Metabolic profiling of Hoodia, Chamomile, Terminalia Species and evaluation of commercial preparations using Ultra-High Performance Quadrupole Time of Flight-Mass Spectrometry

USDA-ARS?s Scientific Manuscript database

Ultra-High Performance-Quadrupole Time of Flight Mass Spectrometr(UHPLC-QToF-MS)profiling has become an impattant tool for identification of marker compounds and generation of metabolic patterns that could be interrogated using chemometric modeling software. Chemometric approaches can be used to ana...

Ultra-high-performance supercritical fluid chromatography with quadrupole-time-of-flight mass spectrometry (UHPSFC/QTOF-MS) for analysis of lignin-derived monomeric compounds in processed lignin samples.

PubMed

Prothmann, Jens; Sun, Mingzhe; Spégel, Peter; Sandahl, Margareta; Turner, Charlotta

2017-12-01

The conversion of lignin to potentially high-value low molecular weight compounds often results in complex mixtures of monomeric and oligomeric compounds. In this study, a method for the quantitative and qualitative analysis of 40 lignin-derived compounds using ultra-high-performance supercritical fluid chromatography coupled to quadrupole-time-of-flight mass spectrometry (UHPSFC/QTOF-MS) has been developed. Seven different columns were explored for maximum selectivity. Makeup solvent composition and ion source settings were optimised using a D-optimal design of experiment (DoE). Differently processed lignin samples were analysed and used for the method validation. The new UHPSFC/QTOF-MS method showed good separation of the 40 compounds within only 6-min retention time, and out of these, 36 showed high ionisation efficiency in negative electrospray ionisation mode. Graphical abstract A rapid and selective method for the quantitative and qualitative analysis of 40 lignin-derived compounds using ultra-high-performance supercritical fluid chromatography coupled to quadrupole-time-of-flight mass spectrometry (UHPSFC/QTOF-MS).

Phenolic profiling of the skin, pulp and seeds of Albariño grapes using hybrid quadrupole time-of-flight and triple-quadrupole mass spectrometry.

PubMed

Di Lecce, Giuseppe; Arranz, Sara; Jáuregui, Olga; Tresserra-Rimbau, Anna; Quifer-Rada, Paola; Lamuela-Raventós, Rosa M

2014-02-15

This paper describes for the first time a complete characterisation of the phenolic compounds in different anatomical parts of the Albariño grape. The application of high-performance liquid chromatography coupled with two complementary techniques, hybrid quadrupole time-of-flight and triple-quadrupole mass spectrometry, allowed the phenolic composition of the Albariño grape to be unambiguously identified and quantified. A more complete phenolic profile was obtained by product ion and precursor ion scans, while a neutral loss scan at 152 u enabled a fast screening of procyanidin dimers, trimers and their galloylated derivatives. The compounds were confirmed by accurate mass measurements in QqToF-MS and QqToF-MS/MS modes at high resolution, and good fits were obtained for all investigated ions, with errors ranging from 0.2 to 4.5 mDa. To the best of our knowledge, two flavanol monomer hexosides were detected in the grape berry for the first time. Copyright © 2013 Elsevier Ltd. All rights reserved.

Ultra high performance liquid chromatography coupled with electrospray ionization/quadrupole time-of-flight mass spectrometry for the rapid analysis of constituents in the traditional Chinese medicine formula Wu Ji Bai Feng Pill.

PubMed

Duan, Shengnan; Qi, Wen; Zhang, Siwen; Huang, Kunkun; Yuan, Dan

2017-10-01

An ultra high performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight mass spectrometry method in both positive and negative ion modes was established in order to comprehensively investigate the major constituents in Wu Ji Bai Feng Pill. Briefly, a Waters ACQUITY UPLC HSS C 18 column was used to separate the aqueous extract of Wu Ji Bai Feng Pill. A total of 0.1% formic acid in acetonitrile and 0.1% aqueous formic acid v/v were used as the mobile phase. All analytes were determined using quadrupole time-of-flight mass spectrometry with electrospray ionization source in positive and negative ion modes. At length, a total of 173 components including flavones and their glycosides, monoterpene glycosides, triterpene saponins, phenethylalchohol glycosides, iridoid glycosides, phthalides, tanshinones, phenolic acids, sesquiterpenoids and cyclopeptides were identified or tentatively characterized in Wu Ji Bai Feng Pill in an analysis of 16.0 min based on the accurate mass and tandem mass spectrometry behaviors. The developed method is rapid and highly sensitive to characterize the chemical constituents of Wu Ji Bai Feng Pill, which could not only be used for chemical standardization and quality control of Wu Ji Bai Feng Pill, but also be helpful for further study in vivo metabolism of Wu Ji Bai Feng Pill. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Profiling the indole alkaloids in yohimbe bark with ultra-performance liquid chromatography coupled with ion mobility quadrupole time-of-flight mass spectrometry.

PubMed

Sun, Jianghao; Baker, Andrew; Chen, Pei

2011-09-30

An ultra-performance liquid chromatography/ion mobility quadrupole time-of-flight mass spectrometry (UPLC/IM-QTOF-MS) method was developed for profiling the indole alkaloids in yohimbe bark. Many indole alkaloids with the yohimbine or ajmalicine core structure, plus methylated, oxidized and reduced species, were characterized. Common fragments and mass differences are described. It was shown that the use of IMS could provide another molecular descriptor, i.e. molecular shape by rotationally averaged collision cross-section; this is of great value for identification of constituents when reference materials are usually not available. Using the combination of high resolution (~40000) accurate mass measurement with time-aligned parallel (TAP) fragmentation, MS(E) (where E represents collision energy), ion mobility mass spectrometry (IMS) and UPLC chromatography, a total 55 indole alkaloids were characterized and a few new indole alkaloids are reported for the first time. Published in 2011 by John Wiley & Sons, Ltd.

Interfacing an aspiration ion mobility spectrometer to a triple quadrupole mass spectrometer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Adamov, Alexey; Viidanoja, Jyrki; Kaerpaenoja, Esko

2007-04-15

This article presents the combination of an aspiration-type ion mobility spectrometer with a mass spectrometer. The interface between the aspiration ion mobility spectrometer and the mass spectrometer was designed to allow for quick mounting of the aspiration ion mobility spectrometer onto a Sciex API-300 triple quadrupole mass spectrometer. The developed instrumentation is used for gathering fundamental information on aspiration ion mobility spectrometry. Performance of the instrument is demonstrated using 2,6-di-tert-butyl pyridine and dimethyl methylphosphonate.

Investigation of an enhanced resolution triple quadrupole mass spectrometer for high-throughput liquid chromatography/tandem mass spectrometry assays.

PubMed

Yang, Liyu; Amad, Ma'an; Winnik, Witold M; Schoen, Alan E; Schweingruber, Hans; Mylchreest, Iain; Rudewicz, Patrick J

2002-01-01

Triple quadrupole mass spectrometers, when operated in multiple reaction monitoring (MRM) mode, offer a unique combination of sensitivity, specificity, and dynamic range. Consequently, the triple quadrupole is the workhorse for high-throughput quantitation within the pharmaceutical industry. However, in the past, the unit mass resolution of quadrupole instruments has been a limitation when interference from matrix or metabolites cannot be eliminated. With recent advances in instrument design, triple quadrupole instruments now afford mass resolution of less than 0.1 Dalton (Da) full width at half maximum (FWHM). This paper describes the evaluation of an enhanced resolution triple quadrupole mass spectrometer for high-throughput bioanalysis with emphasis on comparison of selectivity, sensitivity, dynamic range, precision, accuracy, and stability under both unit mass (1 Da FWHM) and enhanced (

Laser ablation synthesis of arsenic-phosphide Asm Pn clusters from As-P mixtures. Laser desorption ionisation with quadrupole ion trap time-of-flight mass spectrometry: The mass spectrometer as a synthesizer.

PubMed

Kubáček, Pavel; Prokeš, Lubomír; Pamreddy, Annapurna; Peña-Méndez, Eladia María; Conde, José Elias; Alberti, Milan; Havel, Josef

2018-05-30

Only a few arsenic phosphides are known. A high potential for the generation of new compounds is offered by Laser Ablation Synthesis (LAS) and when Laser Desorption Ionization (LDI) is coupled with simultaneous Time-Of-Flight Mass Spectrometry (TOFMS), immediate identification of the clusters can be achieved. LAS was used for the generation of arsenic phosphides via laser ablation of phosphorus-arsenic mixtures while quadrupole ion trap time-of-flight mass spectrometry (QIT-TOFMS) was used to acquire the mass spectra. Many new As m P n ± clusters (479 binary and 369 mono-elemental) not yet described in the literature were generated in the gas phase and their stoichiometry determined. The likely structures for some of the observed clusters arbitrary selected (20) were computed by density functional theory (DFT) optimization. LAS is an advantageous approach for the generation of new As m P n clusters, while mass spectrometry was found to be an efficient technique for the determination of cluster stoichiometry. The results achieved might inspire the synthesis of new materials. Copyright © 2018 John Wiley & Sons, Ltd.

Applicability of hybrid linear ion trap-high resolution mass spectrometry and quadrupole-linear ion trap-mass spectrometry for mycotoxin analysis in baby food.

PubMed

Rubert, Josep; James, Kevin J; Mañes, Jordi; Soler, Carla

2012-02-03

Recent developments in mass spectrometers have created a paradoxical situation; different mass spectrometers are available, each of them with their specific strengths and drawbacks. Hybrid instruments try to unify several advantages in one instrument. In this study two of wide-used hybrid instruments were compared: hybrid quadrupole-linear ion trap-mass spectrometry (QTRAP®) and the hybrid linear ion trap-high resolution mass spectrometry (LTQ-Orbitrap®). Both instruments were applied to detect the presence of 18 selected mycotoxins in baby food. Analytical parameters were validated according to 2002/657/CE. Limits of quantification (LOQs) obtained by QTRAP® instrument ranged from 0.45 to 45 μg kg⁻¹ while lower limits of quantification (LLOQs) values were obtained by LTQ-Orbitrap®: 7-70 μg kg⁻¹. The correlation coefficients (r) in both cases were upper than 0.989. These values highlighted that both instruments were complementary for the analysis of mycotoxin in baby food; while QTRAP® reached best sensitivity and selectivity, LTQ-Orbitrap® allowed the identification of non-target and unknowns compounds. Copyright © 2011 Elsevier B.V. All rights reserved.

Determination of Grayanotoxins from Rhododendron brachycarpum in Dietary Supplements and Homemade Wine by Liquid Chromatography-Quadrupole Time-of-Flight-Mass Spectrometry and Liquid Chromatography-Tandem Mass Spectrometry.

PubMed

Hwang, Taeik; Noh, Eunyoung; Jeong, Ji Hye; Park, Sung-Kwan; Shin, Dongwoo; Kang, Hoil

2018-02-28

A sensitive and specific high-performance liquid chromatography-quadrupole time-of-flight-mass spectrometry (LC-QTOF-MS) method combined with liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed for the determination of grayanotoxins I and III in dietary supplements and homemade wine. Grayanotoxins I and III were successfully extracted using solid-phase extraction cartridges, characterized by LC-QTOF-MS, and quantitated by LC-MS/MS. The LC-MS/MS calibration curves were linear over concentrations of 10-100 ng/mL (grayanotoxin I) and 20-400 ng/mL (grayanotoxin III). Grayanotoxins I and III were found in 51 foodstuffs, with quantitative determinations revealing total toxin concentrations of 18.4-101 000 ng/mL (grayanotoxin I) and 15.3-56 000 ng/mL (grayanotoxin III). The potential of the validated method was demonstrated by successful quantitative analysis of grayanotoxins I and III in dietary supplements and homemade wine; the method appears suitable for the routine detection of grayanotoxins I and III from Rhododendron brachycarpum.

A fragmentation study of dihydroquercetin using triple quadrupole mass spectrometry and its application for identification of dihydroflavonols in Citrus juices.

PubMed

Abad-García, Beatriz; Garmón-Lobato, Sergio; Berrueta, Luis A; Gallo, Blanca; Vicente, Francisca

2009-09-01

A mass spectrometric method using electrospray ionization with triple quadrupole and quadrupole time-of-flight hybrid (Q-Tof) mass spectrometry has been applied to the structural characterization of dihydroflavonols. This family of compounds has been studied by liquid chromatography/tandem mass spectrometry (LC/MS/MS) for the first time in this work. A comprehensive study of the product ion MS spectra of the [M+H](+) ion of a commercially available standard has been performed. The most useful fragmentations in terms of structural identification are those that involve cleavage of the C-ring, resulting in diagnostic ions of dihydroflavonol family: (1,3)A(0) (+), (1,2)B(0) (+), (1,2)B(0) (+)-CO, (0,2)A(0) (+), (0,2)A(0) (+)-H(2)O, (0,2)A(0) (+)-CO, and (0,2)A(0) (+)-H(2)O-CO, that allow the characterization of the substituents in the A- and B-rings. In addition to those ions, other product ions due to losses of H(2)O and CO molecules from the Y(0) (+) ion were observed. Their fragmentation mechanisms and ion structures have been proposed. The established fragmentation patterns have been used to successfully identity three dihydroflavonols found in tangerine juices for the first time. Copyright (c) 2009 John Wiley & Sons, Ltd.

An efficient approach to identify different chemical markers between fibrous root and rhizome of Anemarrhena asphodeloides by ultra high-performance liquid chromatography quadrupole time-of-flight tandem mass spectrometry with multivariate statistical analysis.

PubMed

Wang, Fang-Xu; Yuan, Jian-Chao; Kang, Li-Ping; Pang, Xu; Yan, Ren-Yi; Zhao, Yang; Zhang, Jie; Sun, Xin-Guang; Ma, Bai-Ping

2016-09-10

An ultra high-performance liquid chromatography quadrupole time-of-flight tandem mass spectrometry approach coupled with multivariate statistical analysis was established and applied to rapidly distinguish the chemical differences between fibrous root and rhizome of Anemarrhena asphodeloides. The datasets of tR-m/z pairs, ion intensity and sample code were processed by principal component analysis and orthogonal partial least squares discriminant analysis. Chemical markers could be identified based on their exact mass data, fragmentation characteristics, and retention times. And the new compounds among chemical markers could be isolated rapidly guided by the ultra high-performance liquid chromatography quadrupole time-of-flight tandem mass spectrometry and their definitive structures would be further elucidated by NMR spectra. Using this approach, twenty-four markers were identified on line including nine new saponins and five new steroidal saponins of them were obtained in pure form. The study validated this proposed approach as a suitable method for identification of the chemical differences between various medicinal parts in order to expand medicinal parts and increase the utilization rate of resources. Copyright © 2016 Elsevier B.V. All rights reserved.

Critical comparison of mass analyzers for forensic hair analysis by ambient ionization mass spectrometry.

PubMed

Duvivier, Wilco F; van Beek, Teris A; Nielen, Michel W F

2016-11-15

Recently, several direct and/or ambient mass spectrometry (MS) approaches have been suggested for drugs of abuse imaging in hair. The use of mass spectrometers with insufficient selectivity could result in false-positive measurements due to isobaric interferences. Different mass analyzers have been evaluated regarding their selectivity and sensitivity for the detection of Δ9-tetrahydrocannabinol (THC) from intact hair samples using direct analysis in real time (DART) ionization. Four different mass analyzers, namely (1) an orbitrap, (2) a quadrupole orbitrap, (3) a triple quadrupole, and (4) a quadrupole time-of-flight (QTOF), were evaluated. Selectivity and sensitivity were assessed by analyzing secondary THC standard dilutions on stainless steel mesh screens and blank hair samples, and by the analysis of authentic cannabis user hair samples. Additionally, separation of isobaric ions by use of travelling wave ion mobility (TWIM) was investigated. The use of a triple quadrupole instrument resulted in the highest sensitivity; however, transitions used for multiple reaction monitoring were only found to be specific when using high mass resolution product ion measurements. A mass resolution of at least 30,000 FWHM at m/z 315 was necessary to avoid overlap of THC with isobaric ions originating from the hair matrix. Even though selectivity was enhanced by use of TWIM, the QTOF instrument in resolution mode could not indisputably differentiate THC from endogenous isobaric ions in drug user hair samples. Only the high resolution of the (quadrupole) orbitrap instruments and the QTOF instrument in high-resolution mode distinguished THC in hair samples from endogenous isobaric interferences. As expected, enhanced selectivity compromises sensitivity and THC was only detectable in hair from heavy users. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Characterization of goat colostrum oligosaccharides by nano-liquid chromatography on chip quadrupole time-of-flight mass spectrometry and hydrophilic interaction liquid chromatography-quadrupole mass spectrometry

PubMed Central

Martín-Ortiz, A.; Salcedo, J.; Barile, D.; Bunyatratchata, A.; Moreno, F.J.; Martin-García, I.; Clemente, A.; Sanz, M.L.; Ruiz-Matute, A.I.

2016-01-01

A detailed qualitative and quantitative characterization of goat colostrum oligosaccharides (GCO) has been carried out for the first time. Defatted and deproteinized colostrum samples, previously treated by size exclusion chromatography (SEC) to remove lactose, were analyzed by nanoflow liquid chromatography-quadrupole-time of flight mass spectrometry (Nano-LC-Chip-Q-TOF MS). Up to 78 oligosaccharides containing hexose, hexosamine, fucose, N-acetylneuraminic acid or N-glycolylneuraminic acid monomeric units were identified in the samples, some of them detected for the first time in goat colostra. As a second step, a hydrophilic interaction liquid chromatography coupled to mass spectrometry (HILIC-MS) methodology was developed for the separation and quantitation of the main GCO, both acidic and neutral carbohydrates. Among other experimental chromatographic conditions, mobile phase additives and column temperature were evaluated in terms of retention time, resolution, peak width and symmetry of target carbohydrates. Narrow peaks (wh: 0.2–0.6 min) and good symmetry (As: 0.8–1.4) were obtained for GCO using an acetonitrile:water gradient with 0.1% ammonium hydroxide at 40 °C. These conditions were selected to quantify the main oligosaccharides in goat colostrum samples. Values ranging from 140 to 315 mg L−1 for neutral oligosaccharides and from 83 to 251 mg L−1 for acidic oligosaccharides were found. The combination of both techniques resulted to be useful to achieve a comprehensive characterization of GCO. PMID:26427327

Mass Spectrometry for Research and Application in Therapeutic Drug Monitoring or Clinical and Forensic Toxicology.

PubMed

Maurer, Hans H

2018-04-30

This paper reviews current applications of various hyphenated low- and high-resolution mass spectrometry techniques in the field of therapeutic drug monitoring and clinical/forensic toxicology in both research and practice. They cover gas chromatography, liquid chromatography, matrix-assisted laser desorption ionization, or paper spray ionization coupled to quadrupole, ion trap, time-of-flight, or Orbitrap mass analyzers.

Evaluating Mass Analyzers as Candidates for Small, Portable, Rugged Single Point Mass Spectrometers for Analysis of Permanent Gases

NASA Technical Reports Server (NTRS)

Arkin, C. Richard; Ottens, Andrew K.; Diaz, Jorge A.; Griffin, Timothy P.; Follestein, Duke; Adams, Fredrick; Steinrock, T. (Technical Monitor)

2001-01-01

For Space Shuttle launch safety, there is a need to monitor the concentration Of H2, He, O2, and Ar around the launch vehicle. Currently a large mass spectrometry system performs this task, using long transport lines to draw in samples. There is great interest in replacing this stationary system with several miniature, portable, rugged mass spectrometers which act as point sensors which can be placed at the sampling point. Five commercial and two non-commercial analyzers are evaluated. The five commercial systems include the Leybold Inficon XPR-2 linear quadrupole, the Stanford Research (SRS-100) linear quadrupole, the Ferran linear quadrupole array, the ThermoQuest Polaris-Q quadrupole ion trap, and the IonWerks Time-of-Flight (TOF). The non-commercial systems include a compact double focusing sector (CDFMS) developed at the University of Minnesota, and a quadrupole ion trap (UF-IT) developed at the University of Florida.

Structural characterization of product ions of regulated veterinary drugs by electrospray ionization and quadrupole time-of-flight mass spectrometry (part 3) Anthelmintics, thyreostats, and flukicides

USDA-ARS?s Scientific Manuscript database

RATIONALE: Previously we have reported a liquid chromatography tandem mass spectrometry method for the identification and quantification of regulated veterinary drugs. The methods used three selected transition ions but most of these ions lacked structural characterization. The work presented here ...

Development of a quadrupole-based Secondary-Ion Mass Spectrometry (SIMS) system at Lewis Research Center

NASA Technical Reports Server (NTRS)

Vargas-Aburto, Carlos; Aron, Paul R.; Liff, Dale R.

1990-01-01

The design, construction, and initial use of an ion microprobe to carry out secondary ion mass spectrometry (SIMS) of solid samples is reported. The system is composed of a differentially pumped custom-made UHV (Ultra High Vacuum) chamber, a quadrupole mass spectrometer and a telefocus A-DIDA ion gun with the capability of producing beams of Cesium, as well as inert and reactive gases. The computer control and acquisition of the data were designed and implemented using a personal computer with plug-in boards, and external circuitry built as required to suit the system needs. The software is being developed by using a FORTH-like language. Initial tests aimed at characterizing the system, as well as preliminary surface and depth-profiling studies are presently underway.

Silver/oxygen depth profile in coins by using laser ablation, mass quadrupole spectrometer and X-rays fluorescence

NASA Astrophysics Data System (ADS)

Cutroneo, M.; Torrisi, L.; Caridi, F.; Sayed, R.; Gentile, C.; Mondio, G.; Serafino, T.; Castrizio, E. D.

2013-05-01

Silver coins belonging to different historical periods were investigated to determine the Ag/O atomic ratio depth profiles. Laser ablation has been employed to remove, in high vacuum, the first superficial layers of the coins. Mass quadrupole spectrometry has been used to detect the Ag and the O atomic elements vaporized from the coin surface. The depth profile allowed to determine the thickness of the oxidation layer indicating that, in general, it is high in old coins. A complementary technique, using scanning electron microscope and the associated XRF microprobe, have been devoted to confirm the measurements of Ag/O atomic ratio measured with the laser-coupled mass spectrometry. The oxidation layer thicknesses range between about 25 and 250 microns.

Structural characterization of product ions by electrospray ionization and quadrupole time-of-flight mass spectrometry to support regulatory analysis of veterinary drug residues in foods Part 2: Benzimidazoles nitromidaz.....

USDA-ARS?s Scientific Manuscript database

RATIONALE: Analysis for identification and quantification of regulated veterinary drug residues in foods are usually achieved by liquid chromatography coupled to tandem mass spectrometry. The instrument method requires the selection of characteristic ions, but structure elucidation is seldom perform...

Characterization of goat colostrum oligosaccharides by nano-liquid chromatography on chip quadrupole time-of-flight mass spectrometry and hydrophilic interaction liquid chromatography-quadrupole mass spectrometry.

PubMed

Martín-Ortiz, A; Salcedo, J; Barile, D; Bunyatratchata, A; Moreno, F J; Martin-García, I; Clemente, A; Sanz, M L; Ruiz-Matute, A I

2016-01-08

A detailed qualitative and quantitative characterization of goat colostrum oligosaccharides (GCO) has been carried out for the first time. Defatted and deproteinized colostrum samples, previously treated by size exclusion chromatography (SEC) to remove lactose, were analyzed by nanoflow liquid chromatography-quadrupole-time of flight mass spectrometry (Nano-LC-Chip-Q-TOF MS). Up to 78 oligosaccharides containing hexose, hexosamine, fucose, N-acetylneuraminic acid or N-glycolylneuraminic acid monomeric units were identified in the samples, some of them detected for the first time in goat colostra. As a second step, a hydrophilic interaction liquid chromatography coupled to mass spectrometry (HILIC-MS) methodology was developed for the separation and quantitation of the main GCO, both acidic and neutral carbohydrates. Among other experimental chromatographic conditions, mobile phase additives and column temperature were evaluated in terms of retention time, resolution, peak width and symmetry of target carbohydrates. Narrow peaks (wh: 0.2-0.6min) and good symmetry (As: 0.8-1.4) were obtained for GCO using an acetonitrile:water gradient with 0.1% ammonium hydroxide at 40°C. These conditions were selected to quantify the main oligosaccharides in goat colostrum samples. Values ranging from 140 to 315mgL(-1) for neutral oligosaccharides and from 83 to 251mgL(-1) for acidic oligosaccharides were found. The combination of both techniques resulted to be useful to achieve a comprehensive characterization of GCO. Copyright © 2015 Elsevier B.V. All rights reserved.

Differentiation of regioisomeric aromatic ketocarboxylic acids by atmospheric pressure chemical ionization CAD tandem mass spectrometry in a linear quadrupole ion trap mass spectrometer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Amundson, Lucas M.; Owen, Ben C.; Gallardo, Vanessa A.

2011-01-01

Positive-mode atmospheric pressure chemical ionization tandem mass spectrometry (APCI-MS n ) was tested for the differentiation of regioisomeric aromatic ketocarboxylic acids. Each analyte forms exclusively an abundant protonated molecule upon ionization via positive-mode APCI in a commercial linear quadrupole ion trap (LQIT) mass spectrometer. Energy-resolved collision-activated dissociation (CAD) experiments carried out on the protonated analytes revealed fragmentation patterns that varied based on the location of the functional groups. Unambiguous differentiation between the regioisomers was achieved in each case by observing different fragmentation patterns, different relative abundances of ion-molecule reaction products, or different relative abundances of fragment ions formed at differentmore » collision energies. The mechanisms of some of the reactions were examined by H/D exchange reactions and molecular orbital calculations.« less

Use of liquid chromatography hybrid triple-quadrupole mass spectrometry for the detection of emodin metabolites in rat bile and urine.

PubMed

Wu, Songyan; Zhang, Yaqing; Zhang, Zunjian; Song, Rui

2017-10-01

Emodin is the representative form of rhubarb, which is widely used in traditional Chinese medicine for the treatment of purgative, anti-inflammatory, antioxidative and antiviral, etc. Previous reports demonstrated that emodin glucuronide was the major metabolite in plasma. Owing to the extensive conjugation reactions of polyphenols, the aim of this study was to identify the metabolites of emodin in rat bile and urine. Neutral loss and precursor ion scan methods of triple-quadrupole mass spectrometer revealed 13 conjugated metabolites in rat bile and 22 metabolites in rat urine, which included four phase I and 18 phase II metabolites. The major metabolites in rat biosamples were emodin glucuronoconjugates. Moreover, rhein monoglucuronide, chrysophanol monoglucuronide and rhein sulfate were proposed for the first time after oral administration of emodin. Overall, liquid chromatography hybrid triple-quadrupole mass spectrometry analysis leads to the discovery of several novel emodin metabolites in rat bile and urine and underscores that conjugated with glucuronic acid is the main metabolic pathway. Copyright © 2017 John Wiley & Sons, Ltd.

Ion-mobility study of two functionalized pentacene structural isomers using a modified electrospray/triple quadrupole mass spectrometer

NASA Astrophysics Data System (ADS)

Prada, Svitlana V.; Bohme, Diethard K.; Baranov, Vladimir I.

2007-03-01

We report ion-mobility measurements with a modified triple quadrupole mass spectrometer fitted with an ion molecule reactor (IMR) designed to investigate ion molecule reactivity in organic mass spectrometry. Functionalized pentacene ions, which are generally unreactive were chosen for study to decouple drift/diffusion effects from reactivity (including clustering). The IMR is equipped with a variable axial electrostatic drift field (ADF) and is able to trap ions. These capabilities were successfully employed in the measurement of ion mobilities in different modes of IMR operation. Theoretical modeling of the drift dynamics and the special localization of the large ion packet was successfully implemented. The contribution of the quadrupole RF field to the drift dynamics also was taken into consideration.

Analysis of non-steroidal anti-inflammatory drugs in milk using QuEChERS and liquid chromatography coupled to mass spectrometry: triple quadrupole versus Q-Orbitrap mass analyzers.

PubMed

Rúbies, Antoni; Guo, Lili; Centrich, Francesc; Granados, Mercè

2016-08-01

We developed a Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) method for the high throughput determination of 10 non-steroidal anti-inflammatory drugs (NSAIDs) in milk samples using high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) with a triple quadrupole (QqQ) instrument and an electrospray ionization (ESI) source. The new extraction procedure is highly efficient, and we obtained absolute recoveries in the range 78.1-97.1 % for the extraction and clean-up steps. Chromatographic separation is performed in the gradient mode with a biphenyl column and acidic mobile phases consisting of water and acetonitrile containing formic acid. The chromatographic run time was about 12 min, and NSAID peaks showed a good symmetry factor. For MS/MS detection, we used multiple reaction monitoring (MRM) mode, using ESI in both positive and negative modes. Our method has been validated in compliance with the European Commission Decision 657/2002/EC, and we obtained very satisfactory results in inter-laboratory testing. Furthermore, we explored the use of a hybrid high resolution mass spectrometer, combining a quadrupole and an Orbitrap mass analyzer, for high resolution (HR) MS/MS detection of NSAIDs. We achieved lower NSAID quantification limits with Q-Orbitrap high resolution mass spectrometry (HRMS/MS) detection than those achieved with the QqQ instrument; however, its main feature is its very high selectivity, which makes HRMS/MS particularly suitable for confirmatory analysis.

Quantification of steroid hormones in human serum by liquid chromatography-high resolution tandem mass spectrometry.

PubMed

Matysik, Silke; Liebisch, Gerhard

2017-12-01

A limited specificity is inherent to immunoassays for steroid hormone analysis. To improve selectivity mass spectrometric analysis of steroid hormones by liquid chromatography-tandem mass spectrometry (LC-MS/MS) has been introduced in the clinical laboratory over the past years usually with low mass resolution triple-quadrupole instruments or more recently by high resolution mass spectrometry (HR-MS). Here we introduce liquid chromatography-high resolution tandem mass spectrometry (LC-MS/HR-MS) to further increase selectivity of steroid hormone quantification. Application of HR-MS demonstrates an enhanced selectivity compared to low mass resolution. Separation of isobaric interferences reduces background noise and avoids overestimation. Samples were prepared by automated liquid-liquid extraction with MTBE. The LC-MS/HR-MS method using a quadrupole-Orbitrap analyzer includes eight steroid hormones i.e. androstenedione, corticosterone, cortisol, cortisone, 11-deoxycortisol, 17-hydroxyprogesterone, progesterone, and testosterone. It has a run-time of 5.3min and was validated according to the U.S. Food and Drug Administration (FDA) and the European Medicines Agency (EMA) guidelines. For most of the analytes coefficient of variation were 10% or lower and LOQs were determined significantly below 1ng/ml. Full product ion spectra including accurate masses substantiate compound identification by matching their masses and ratios with authentic standards. In summary, quantification of steroid hormones by LC-MS/HR-MS is applicable for clinical diagnostics and holds also promise for highly selective quantification of other small molecules. Copyright © 2017 Elsevier B.V. All rights reserved.

Fast analysis of doping agents in urine by ultra-high-pressure liquid chromatography-quadrupole time-of-flight mass spectrometry. II: Confirmatory analysis.

PubMed

Badoud, F; Grata, E; Perrenoud, L; Saugy, M; Rudaz, S; Veuthey, J-L

2010-06-18

For doping control, analyses of samples are generally achieved in two steps: a rapid screening and, in the case of a positive result, a confirmatory analysis. A two-step methodology based on ultra-high-pressure liquid chromatography coupled to a quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS) was developed to screen and confirm 103 doping agents from various classes (e.g., beta-blockers, stimulants, diuretics, and narcotics). The screening method was presented in a previous article as part I (i.e., Fast analysis of doping agents in urine by ultra-high-pressure liquid chromatography-quadrupole time-of-flight mass spectrometry. Part I: screening analysis). For the confirmatory method, basic, neutral and acidic compounds were extracted by a dedicated solid-phase extraction (SPE) in a 96-well plate format and detected by MS in the tandem mode to obtain precursor and characteristic product ions. The mass accuracy and the elemental composition of precursor and product ions were used for compound identification. After validation including matrix effect determination, the method was considered reliable to confirm suspect results without ambiguity according to the positivity criteria established by the World Anti-Doping Agency (WADA). Moreover, an isocratic method was developed to separate ephedrine from its isomer pseudoephedrine and cathine from phenylpropanolamine in a single run, what allowed their direct quantification in urine. Copyright (c) 2010 Elsevier B.V. All rights reserved.

A New Approach To Selectively Identify And Quantify Perfluorochemicals In Complex Matrices Using Ion Trap Time-Of-Flight Mass Spectrometry

EPA Science Inventory

Most of the published studies focusing on the environmental and biological distribution of perfluorinated alkyl compounds (PFCs) have used triple quadrupole mass spectrometers for compound identification and quantitation. Multiple-reaction-monitoring (MRM) is a sensitive mass sp...

Metabolism studies of benzbromarone in rats by high performance liquid chromatography-quadrupole time of flight mass spectrometry.

PubMed

Wu, Haiqing; Peng, Ying; Wang, Shaojie; Wang, Kai; Zhao, Xunchen; Jiang, Fan

2012-12-12

A high performance liquid chromatography-quadrupole time of flight mass spectrometry (HPLC-QTOF-MS) method was employed in investigation of benzbromarone metabolites in rat plasma, urine, feces and bile samples. Meanwhile, the metabolic pathways of benzbromarone in rats were discussed. The identification was achieved on a reversed-phase C(18) column with mobile phase gradient method. The QTOF-MS was operated under full scan of MS or MS/MS in negative mode. The fragments were acquired by raising collision induced dissociation (CID) energy for speculating the structures of parent ions. According to the information from the chromatograms and mass spectra, 17 metabolites were obtained. Among them, the deoxidized phase I metabolites and an array of phase II metabolites-sulfate conjugates detected in the biological samples made the work more significant. Copyright © 2012 Elsevier B.V. All rights reserved.

Identification of non-volatile compounds and their migration from hot melt adhesives used in food packaging materials characterized by ultra-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry.

PubMed

Vera, Paula; Canellas, Elena; Nerín, Cristina

2013-05-01

The identification of unknown non-volatile migrant compounds from adhesives used in food contact materials is a very challenging task because of the number of possible compounds involved, given that adhesives are complex mixtures of chemicals. The use of ultra-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (UPLC-MS/QTOF) is shown to be a successful tool for identifying non-targeted migrant compounds from two hot melt adhesives used in food packaging laminates. Out of the seven migrants identified and quantified, five were amides and one was a compound classified in Class II of the Cramer toxicity. None of the migration values exceeded the recommended Cramer exposure values.

Airfoil sampling of a pulsed Laval beam with tunable vacuum ultraviolet synchrotron ionization quadrupole mass spectrometry: application to low-temperature kinetics and product detection.

PubMed

Soorkia, Satchin; Liu, Chen-Lin; Savee, John D; Ferrell, Sarah J; Leone, Stephen R; Wilson, Kevin R

2011-12-01

A new pulsed Laval nozzle apparatus with vacuum ultraviolet (VUV) synchrotron photoionization quadrupole mass spectrometry is constructed to study low-temperature radical-neutral chemical reactions of importance for modeling the atmosphere of Titan and the outer planets. A design for the sampling geometry of a pulsed Laval nozzle expansion has been developed that operates successfully for the determination of rate coefficients by time-resolved mass spectrometry. The new concept employs airfoil sampling of the collimated expansion with excellent sampling throughput. Time-resolved profiles of the high Mach number gas flow obtained by photoionization signals show that perturbation of the collimated expansion by the airfoil is negligible. The reaction of C(2)H with C(2)H(2) is studied at 70 K as a proof-of-principle result for both low-temperature rate coefficient measurements and product identification based on the photoionization spectrum of the reaction product versus VUV photon energy. This approach can be used to provide new insights into reaction mechanisms occurring at kinetic rates close to the collision-determined limit.

High-resolution liquid chromatography/electrospray ionization time-of-flight mass spectrometry combined with liquid chromatography/electrospray ionization tandem mass spectrometry to identify polyphenols from grape antioxidant dietary fiber.

PubMed

Touriño, Sonia; Fuguet, Elisabet; Jáuregui, Olga; Saura-Calixto, Fulgencio; Cascante, Marta; Torres, Josep Lluís

2008-11-01

Grape antioxidant dietary fiber (GADF) is a dietary supplement that combines the benefits of both fiber and antioxidants that help prevent cancer and cardiovascular diseases. The antioxidant polyphenolic components in GADF probably help prevent cancer in the digestive tract, where they are bioavailable. Mass spectrometry coupled to liquid chromatography is a powerful tool for the analysis of complex plant derivatives such as GADF. We use a combination of MS techniques, namely liquid chromatography/electrospray ionization time-of-flight mass spectrometry (LC/ESI-TOF-MS) and liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) on a triple quadrupole, for the identification of the polyphenolic constituents of the soluble fraction of GADF. First, we separated the mixture into four fractions which were tested for phenolic constituents using the TOF system in the full scan mode. The high sensitivity and resolution of the TOF detector over the triple quadrupole facilitate the preliminary characterization of the fractions. Then we used LC/ESI-MS/MS to identify the individual phenols through MS/MS experiments (product ion scan, neutral loss scan, precursor ion scan). Finally, most of the identities were unequivocally confirmed by accurate mass measurements on the TOF spectrometer. LC/ESI-TOF-MS combined with MS/MS correctly identifies the bioactive polyphenolic components from the soluble fraction of GADF. High-resolution TOF-MS is particularly useful for identifying the structure of compounds with the same LC/ESI-MS/MS fragmentation patterns.

Characterization of carbonyl by-products during Uniblu-A ozonation by liquid chromatography/hybrid quadrupole time-of-flight/mass spectrometry.

PubMed

Amorisco, A; Locaputo, V; Mascolo, G

2011-07-15

The structural elucidation of carbonyl-containing by-products arising from Uniblu-OH ozonation has been investigated by liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) employing a quadrupole time-of-flight mass spectrometer. The by-products were derivatized with 2,4-dinitrophenylhydrazine, allowing the formation of [M-H](-) ions of the derivatives in the electrospray source. Exact mass measurements of both the [M-H](-) ions and their product ions allowed the elemental formulae and related structures of ten by-products to be determined confidently. The main degradation pathway were decarboxylation followed by further oxidation. It is noteworthy that the experimental procedure employed allowed the identification of both nitrogen- and sulphur-containing carbonyl by-products during Uniblu-OH ozonation. This result is of environmental relevance for monitoring the balance of organic nitrogen and sulphur during the ozonation of organic pollutants. These atoms, in fact, do not undergo complete mineralization. Copyright © 2011 John Wiley & Sons, Ltd.

Chemical profiling of Qixue Shuangbu Tincture by ultra-performance liquid chromatography with electrospray ionization quadrupole-time-of-flight high-definition mass spectrometry (UPLC-QTOF/MS).

PubMed

Chen, Lin-Wei; Wang, Qin; Qin, Kun-Ming; Wang, Xiao-Li; Wang, Bin; Chen, Dan-Ni; Cai, Bao-Chang; Cai, Ting

2016-02-01

The present study was designed to develop and validate a sensitive and reliable ultra high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-QTOF/MS) method to separate and identify the chemical constituents of Qixue Shuangbu Tincture (QXSBT), a classic traditional Chinese medicine (TCM) prescription. Under the optimized UPLC and QTOF/MS conditions, 56 components in QXSBT, including chalcones, triterpenoids, protopanaxatriol, flavones and flavanones were identified and tentatively characterized within a running time of 42 min. The components were identified by comparing the retention times, accurate mass, and mass spectrometric fragmentation characteristic ions, and matching empirical molecular formula with that of the published compounds. In conclusion, the established UPLC-QTOF/MS method was reliable for a rapid identification of complicated components in the TCM prescriptions. Copyright © 2016 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.

Qualitative analysis of seized synthetic cannabinoids and synthetic cathinones by gas chromatography triple quadrupole tandem mass spectrometry.

PubMed

Gwak, Seongshin; Arroyo-Mora, Luis E; Almirall, José R

2015-02-01

Designer drugs are analogues or derivatives of illicit drugs with a modification of their chemical structure in order to circumvent current legislation for controlled substances. Designer drugs of abuse have increased dramatically in popularity all over the world for the past couple of years. Currently, the qualitative seized-drug analysis is mainly performed by gas chromatography-electron ionization-mass spectrometry (GC-EI-MS) in which most of these emerging designer drug derivatives are extensively fragmented not presenting a molecular ion in their mass spectra. The absence of molecular ion and/or similar fragmentation pattern among these derivatives may cause the equivocal identification of unknown seized-substances. In this study, the qualitative identification of 34 designer drugs, mainly synthetic cannabinoids and synthetic cathinones, were performed by gas chromatography-triple quadrupole-tandem mass spectrometry with two different ionization techniques, including electron ionization (EI) and chemical ionization (CI) only focusing on qualitative seized-drug analysis, not from the toxicological point of view. The implementation of CI source facilitates the determination of molecular mass and the identification of seized designer drugs. Developed multiple reaction monitoring (MRM) mode may increase sensitivity and selectivity in the analysis of seized designer drugs. In addition, CI mass spectra and MRM mass spectra of these designer drug derivatives can be used as a potential supplemental database along with EI mass spectral database. Copyright © 2014 John Wiley & Sons, Ltd.

Proton-transfer reaction mass spectrometry (PTRMS) in combination with thermal desorption (TD) for sensitive off-line analysis of volatiles.

PubMed

Crespo, Elena; Devasena, Samudrala; Sikkens, Cor; Centeno, Raymund; Cristescu, Simona M; Harren, Frans J M

2012-04-30

When performing trace gas analysis, it is not always possible to bring the source of volatiles and the gas analyzer together. In these cases, volatile storage containers, such as thermal desorption (TD) tubes, can be used for off-line measurement. TD is routinely combined with gas chromatography/mass spectrometry (GC/MS), but so far not with proton-transfer reaction mass spectrometry (PTRMS), which has a faster response. A PTR-quadrupole-MS instrument and a PTR-ion-trap-MS instrument were separately coupled to a TD unit for off-line analysis of trace volatiles in air. Carbograph 1TD/Carbopack X sorbent tubes were filled with different concentrations of a trace gas mixture containing low molecular weight volatiles (32 g/mol up to 136 g/mol) and measured with the above-mentioned combinations. The carrier gas in the TD unit was changed from helium to nitrogen to be able to combine this instrument with the mass spectrometer. Good linearity and reproducibility with the amount of gas stored were obtained. The storage capacity over time (up to 14 days) showed larger variability (<11% for all compounds, except for acetone 27%). Several tubes were filled with breath of different persons, and the breath of a smoker showed increased levels of acetonitrile and benzene. The combination of the PTR ion-trap instrument with the TD unit was also investigated. Due to its higher sampling rate, the ion-trap system showed higher throughput capabilities than the quadrupole system. The combination of TD with PTRMS using both a quadrupole and an ion trap for off-line volatile analysis has been validated. TD tubes can be a robust and compact volatile storage method when the mass spectrometry and the sampling cannot be performed in the same place, for example in large screening studies. In addition, a higher measurement throughput than with GC/MS could be obtained. Copyright © 2012 John Wiley & Sons, Ltd.

Measuring masses of single bacterial whole cells with a quadrupole ion trap.

PubMed

Peng, Wen-Ping; Yang, Yi-Chang; Kang, Ming-Wei; Lee, Yuan T; Chang, Huan-Cheng

2004-09-29

A novel method has been developed to precisely measure the masses of single bacterial whole cells using a quadrupole ion trap as an electrodynamic balance. The bacterial cells were introduced into the ion trap by matrix-assisted laser desorption/ionization, confined in space by audio frequency ac fields, and detected by elastic light scattering. Mass measurement accuracy approaching 0.1% was achieved for Escherichia coli K-12 with a mass distribution of +/-3% from 60 repetitive measurements of the particles and their clusters. This is the first high-precision mass measurement reported for any intact microorganisms with masses greater than 1 x 1010 Da. The method opens new avenues for high-precision mass measurement of single microbial particles and offers an alternative approach for rapid identification of microorganisms by mass spectrometry.

Electrospray ionization tandem mass spectrometry of ammonium cationized polyethers.

PubMed

Nasioudis, Andreas; Heeren, Ron M A; van Doormalen, Irene; de Wijs-Rot, Nicolette; van den Brink, Oscar F

2011-05-01

Quaternary ammonium salts (Quats) and amines are known to facilitate the MS analysis of high molar mass polyethers by forming low charge state adduct ions. The formation, stability, and behavior upon collision-induced dissociation (CID) of adduct ions of polyethers with a variety of Quats and amines were studied by electrospray ionization quadrupole time-of-flight, quadrupole ion trap, and linear ion trap tandem mass spectrometry (MS/MS). The linear ion trap instrument was part of an Orbitrap hybrid mass spectrometer that allowed accurate mass MS/MS measurements. The Quats and amines studied were of different degree of substitution, structure, and size. The stability of the adduct ions was related to the structure of the cation, especially the amine's degree of substitution. CID of singly/doubly charged primary and tertiary ammonium cationized polymers resulted in the neutral loss of the amine followed by fragmentation of the protonated product ions. The latter reveals information about the monomer unit, polymer sequence, and endgroup structure. In addition, the detection of product ions retaining the ammonium ion was observed. The predominant process in the CID of singly charged quaternary ammonium cationized polymers was cation detachment, whereas their doubly charged adduct ions provided the same information as the primary and tertiary ammonium cationized adduct ions. This study shows the potential of specific amines as tools for the structural elucidation of high molar mass polyethers. © American Society for Mass Spectrometry, 2011

Alkaloid profiling of the traditional Chinese medicine Rhizoma corydalis using high performance liquid chromatography-tandem quadrupole time-of-flight mass spectrometry

PubMed Central

Sun, Mingqian; Liu, Jianxun; Lin, Chengren; Miao, Lan; Lin, Li

2014-01-01

Since alkaloids are the major active constituents of Rhizoma corydalis (RC), a convenient and accurate analytical method is needed for their identification and characterization. Here we report a method to profile the alkaloids in RC based on liquid chromatography-tandem quadrupole time-of-flight mass spectrometry (LC–Q-TOF-MS/MS). A total of 16 alkaloids belonging to four different classes were identified by comparison with authentic standards. The fragmentation pathway of each class of alkaloid was clarified and their differences were elucidated. Furthermore, based on an analysis of fragmentation pathways and alkaloid profiling, a rapid and accurate method for the identification of unknown alkaloids in RC is proposed. The method could also be useful for the quality control of RC. PMID:26579385

Qualitative and quantitative characterization of secondary metabolites and carbohydrates in Bai-Hu-Tang using ultraperformance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry and ultraperformance liquid chromatography coupled with photodiode array detector.

PubMed

Zhong, Wei-Fang; Tong, Wing-Sum; Zhou, Shan-Shan; Yip, Ka-Man; Li, Song-Lin; Zhao, Zhong-Zhen; Xu, Jun; Chen, Hu-Biao

2017-10-01

Bai-Hu-Tang (BHT), a classic traditional Chinese medicine (TCM) formula used for clearing heat and promoting body fluid, consists of four traditional Chinese medicines, i.e., Gypsum Fibrosum (Shigao), Anemarrhenae Rhizoma (Zhimu), Glycyrrhizae Radix et Rhizoma Praeparata cum Melle (Zhigancao), and nonglutinous rice (Jingmi). The chemical composition of BHT still remains largely elusive thus far. To qualitatively and quantitatively characterize secondary metabolites and carbohydrates in BHT, here a combination of analytical approaches using ultraperformance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry and ultraperformance liquid chromatography coupled with photodiode array detector was developed and validated. A total of 42 secondary metabolites in BHT were tentatively or definitely identified, of which 10 major chemicals were quantified by the extracting ion mode of quadrupole time-of-flight mass spectrometry. Meanwhile, polysaccharides, oligosaccharides, and monosaccharides in BHT were also characterized via sample pretreatment followed by sugar composition analysis. The quantitative results indicated that the determined chemicals accounted for 35.76% of the total extract of BHT, which demonstrated that the study could be instrumental in chemical dissection and quality control of BHT. The research deliverables not only laid the root for further chemical and biological evaluation of BHT, but also provided a comprehensive analytical strategy for chemical characterization of secondary metabolites and carbohydrates in traditional Chinese medicine formulas. Copyright © 2017. Published by Elsevier B.V.

Simultaneous Determination of Ten Constituents in Chaiqin Qingning Capsule by High-performance Liquid Chromatography Coupled with Triple-quadrupole Mass Spectrometry

PubMed Central

Li, Ting Yu; Huo, Xiao Kui; Zheng, Lu; Wang, Chao; Cong, Hai Jian; Xiang, Ting; Zhang, Lin; Zhang, Bao Jing; Huang, Shan Shan; Wu, Bin; Li, Xin Yu

2017-01-01

Background: Chaiqin Qingning Capsule (CQQNC) was a prescription of Traditional Chinese Medicine with the effects of clearing away heat and removing toxin, harmonizing the exterior and interior, it was widely used in Asian, for example, China and Japan, different batches of the raws materials and different processing time may be the vital factor which raised a challenge to control the quality of the CQQNC. Experimental Methods: In this experiment, a high-performance liquid chromatography-mass spectrometry/MS (HPLC-MS/MS) method was developed to simultaneously determine ten bioactive components for the quality control of CQQNC. Chromatographic separation was achieved using an XBridge BEH C18 column (150 mm × 4.6 mm, 2.5 μm) with a mobile phase composed of 10 mm aqueous ammonium acetate and acetonitrile using a gradient elution in 20 min. This study was conducted by multiple reaction monitoring mode through electrospray ionization resource with a negative ionization mode. Results: The established method was validated with good performance of precision, accuracy, stability, and reproducibility and was utilized to simultaneously quantify ten constituents of CQQNC obtained from seven different batches. Conclusion: It is the first time to report the rapid and simultaneous analysis of the ten compounds in CQQNC by HPLC-MS/MS and apply to determine 10 constituents in 7 batches of CQQNC bought from drug store in china. This method could be considered as good quality criteria to control the quality of CQQNC. SUMMARY In this paper, a simple, specific, and rapid high-performance liquid chromatogram coupled with triple-quadrupole mass spectrometry method for simultaneous quantification of ten constituents in Chaiqin Qingning Capsule has been developed for the first time. This method could be considered as good quality criteria to control the quality of CQQNC. Abbreviations used: CHM: Chinese herbal medicine; TCM: Traditional Chinese Medicine; CQQNC: Triple-quadrupole mass spectrometry Chaiqin Qingning Capsules; HPLC–MS/MS: High liquid chromatography equipped with tandem mass spectrometry; ESI: Electrospray ionization; DP: Declustering potential; CE: Collision energy; RSD: Relative standard deviation; LOD: Limit of detection; LOQ: Limit of quantity. PMID:29200714

Simultaneous Determination of Ten Constituents in Chaiqin Qingning Capsule by High-performance Liquid Chromatography Coupled with Triple-quadrupole Mass Spectrometry.

PubMed

Li, Ting Yu; Huo, Xiao Kui; Zheng, Lu; Wang, Chao; Cong, Hai Jian; Xiang, Ting; Zhang, Lin; Zhang, Bao Jing; Huang, Shan Shan; Wu, Bin; Li, Xin Yu

2017-01-01

Chaiqin Qingning Capsule (CQQNC) was a prescription of Traditional Chinese Medicine with the effects of clearing away heat and removing toxin, harmonizing the exterior and interior, it was widely used in Asian, for example, China and Japan, different batches of the raws materials and different processing time may be the vital factor which raised a challenge to control the quality of the CQQNC. In this experiment, a high-performance liquid chromatography-mass spectrometry/MS (HPLC-MS/MS) method was developed to simultaneously determine ten bioactive components for the quality control of CQQNC. Chromatographic separation was achieved using an XBridge BEH C18 column (150 mm × 4.6 mm, 2.5 μm) with a mobile phase composed of 10 mm aqueous ammonium acetate and acetonitrile using a gradient elution in 20 min. This study was conducted by multiple reaction monitoring mode through electrospray ionization resource with a negative ionization mode. The established method was validated with good performance of precision, accuracy, stability, and reproducibility and was utilized to simultaneously quantify ten constituents of CQQNC obtained from seven different batches. It is the first time to report the rapid and simultaneous analysis of the ten compounds in CQQNC by HPLC-MS/MS and apply to determine 10 constituents in 7 batches of CQQNC bought from drug store in china. This method could be considered as good quality criteria to control the quality of CQQNC. In this paper, a simple, specific, and rapid high-performance liquid chromatogram coupled with triple-quadrupole mass spectrometry method for simultaneous quantification of ten constituents in Chaiqin Qingning Capsule has been developed for the first time. This method could be considered as good quality criteria to control the quality of CQQNC. Abbreviations used: CHM: Chinese herbal medicine; TCM: Traditional Chinese Medicine; CQQNC: Triple-quadrupole mass spectrometry Chaiqin Qingning Capsules; HPLC-MS/MS: High liquid chromatography equipped with tandem mass spectrometry; ESI: Electrospray ionization; DP: Declustering potential; CE: Collision energy; RSD: Relative standard deviation; LOD: Limit of detection; LOQ: Limit of quantity.

Environmental applications for the analysis of chlorinated dibenzo-p-dioxins and dibenzofurans using mass spectrometry/mass spectrometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reiner, E.J.; Schellenberg, D.H.; Taguchi, V.Y.

1991-01-01

A mass spectrometry/mass spectrometry-multiple reaction monitoring (MS/MS-MRM) technique for the analysis of all tetra- through octachlorinated dibenzo-p-dioxins (Cl{sub x}DD, x = 4-8) and dibenzofurans (Cl{sub x}DF, x = 4-8) has been developed at the Ministry of the Environment (MOE) utilizing a triple quadrupole mass spectrometer. Optimization of instrumental parameters using the analyte of interest in a direct insertion probe (DIP) resulted in sensitivities approaching those obtainable by high-resolution mass spectrometric (HRMS) methods. All congeners of dioxins and furans were detected in the femtogram range. Results on selected samples indicated that for some matrices, fewer chemical interferences were observed by MS/MSmore » than by HRMS. The technique used to optimize the instrument for chlorinated dibenzo-p-dioxins (CDDs) and chlorinated dibenzofurans (CDFs) analysis is adaptable to other analytes.« less

Screening and identification of glyceollins and their metabolites by electrospray ionization tandem mass spectrometry with precursor ion scanning

USDA-ARS?s Scientific Manuscript database

A method has been developed for screening glyceollins and their metabolites based upon precursor ion scanning. Under higher-energy collision conditions, employing a triple quadrupole mass spectrometer in the negative ion mode, deprotonated glyceollin precursors yield a diagnostic radical product ion...

Carbon Isotopic Measurements of Amino Acids in Stardust-Returned Samples

NASA Technical Reports Server (NTRS)

Elsila, Jamie

2009-01-01

NASA's Stardust spacecraft returned to Earth samples from comet 81P/Wild 2 in January 2006. Preliminary examinations revealed the presence of a suite of organic compounds including several amines and amino acids, but the origin of these compounds could not be identified. Here, we present the carbon isotopic ratios of glycine and e-aminocaproic acid (EACA), the two most abundant amino acids, in Stardust-returned foil samples measured by gas chromatography-combustion-isotope ratio mass spectrometry coupled with quadrupole mass spectrometry (GC-CAMS/IRMS).

Urinary metabolomic study of non-small cell lung carcinoma based on ultra high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry.

PubMed

Wu, Qian; Wang, Yan; Gu, Xue; Zhou, Junyi; Zhang, Huiping; Lv, Wang; Chen, Zhe; Yan, Chao

2014-07-01

Metabolic profiles from human urine reveal the significant difference of carnitine and acylcarnitines levels between non-small cell lung carcinoma patients and healthy controls. Urine samples from cancer patients and healthy individuals were assayed in this metabolomic study using ultra high performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry. The data were normalized by the sum of all intensities and creatinine calibration, respectively, before orthogonal partial least squares discriminant analysis. Twenty differential metabolites were identified based on standard compounds or tandem mass spectrometry fragments. Among them, some medium-/long-chain acylcarnitines, for example, cis-3,4-methylene heptanoylcarnitine, were found to be downregulated while carnitine was upregulated in urine samples from the cancer group compared to the control group. Receiver operating characteristic analysis of the two groups showed that the area under curve for the combination of carnitine and 11 selected acylcarnitines was 0.958. This study suggests that the developed carnitine and acylcarnitines profiling method has the potential to be used for screening non-small cell lung carcinoma. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Profiling of Arabidopsis secondary metabolites by capillary liquid chromatography coupled to electrospray ionization quadrupole time-of-flight mass spectrometry.

PubMed

von Roepenack-Lahaye, Edda; Degenkolb, Thomas; Zerjeski, Michael; Franz, Mathias; Roth, Udo; Wessjohann, Ludger; Schmidt, Jürgen; Scheel, Dierk; Clemens, Stephan

2004-02-01

Large-scale metabolic profiling is expected to develop into an integral part of functional genomics and systems biology. The metabolome of a cell or an organism is chemically highly complex. Therefore, comprehensive biochemical phenotyping requires a multitude of analytical techniques. Here, we describe a profiling approach that combines separation by capillary liquid chromatography with the high resolution, high sensitivity, and high mass accuracy of quadrupole time-of-flight mass spectrometry. About 2000 different mass signals can be detected in extracts of Arabidopsis roots and leaves. Many of these originate from Arabidopsis secondary metabolites. Detection based on retention times and exact masses is robust and reproducible. The dynamic range is sufficient for the quantification of metabolites. Assessment of the reproducibility of the analysis showed that biological variability exceeds technical variability. Tools were optimized or established for the automatic data deconvolution and data processing. Subtle differences between samples can be detected as tested with the chalcone synthase deficient tt4 mutant. The accuracy of time-of-flight mass analysis allows to calculate elemental compositions and to tentatively identify metabolites. In-source fragmentation and tandem mass spectrometry can be used to gain structural information. This approach has the potential to significantly contribute to establishing the metabolome of Arabidopsis and other model systems. The principles of separation and mass analysis of this technique, together with its sensitivity and resolving power, greatly expand the range of metabolic profiling.

Structural elucidation and identification of a new derivative of phenethylamine using quadrupole time-of-flight mass spectrometry.

PubMed

Sekuła, Karolina; Zuba, Dariusz

2013-09-30

In recent years, the phenomenon of uncontrolled distribution of new psychoactive substances that were marketed without prior toxicological studies has been observed. Because many designer drugs are related in chemical structure, the potential for misidentifying them is an important problem. It is therefore essential to develop an analytical procedure for unequivocal elucidation of the structures of these compounds. The issue has been discussed in the context of 25I-NBMD [2-(4-iodo-2,5-dimethoxyphenyl)-N-[(2,3-methylenedioxyphenyl)methyl]ethanamine], a psychoactive substance first discovered on the drug market in 2012. The substance was extracted from blotter papers with methanol. Separation was achieved via liquid chromatography. Analysis was conducted by electrospray ionization quadrupole time-of-flight mass spectrometry (ESI-QTOFMS). Identification of the psychoactive component was supported by electron impact gas chromatography/mass spectrometry (GC/EI-MS). The high accuracy of the LC/ESI-QTOFMS method allowed the molecular mass of the investigated substance (M(exp) = 441.0438 Da; mass error, ∆m = 0.2 ppm) and the formulae of ions formed during fragmentation to be determined. The main ions were recorded at m/z = 135.0440, 290.9876 and 305.9981. Structures of the obtained ions were elucidated in the tandem mass spectrometry (MS/MS) experiments by comparing them to mass spectra of previously detected derivatives of phenethylamine. The performed study indicated the potential for using LC/QTOFMS method to identify new designer drugs. This technique can be used supplementary to standard GC/MS. Prior knowledge of the fragmentation mechanisms of phenethylamines allowed to predict the mass spectra of the novel substance--25I-NBMD. Copyright © 2013 John Wiley & Sons, Ltd.

Rapid characterisation and identification of compounds in Saposhnikoviae Radix by high-performance liquid chromatography coupled with electrospray ionisation quadrupole time-of-flight mass spectrometry.

PubMed

Chen, Luxiao; Chen, Xiangyang; Su, Lei; Jiang, Yanyan; Liu, Bin

2018-04-01

Saposhnikoviae Radix (SR), the dried root of Saposhnikovia divaricata (Turcz.) Schischk. (Umbelliferae), is commonly used as a traditional Chinese medicine. In this study, a rapid and accurate method was firstly, developed for the qualitative analysis of SR by high-performance liquid chromatography coupled with electrospray ionisation quadrupole time-of-flight mass spectrometry (HPLC-ESI-Q-TOF-MS/MS). A total of 45 compounds were identified or tentatively characterised, including 13 chromones, 28 coumarins and four others. Among them, 16 compounds were identified from SR for the first time. In addition, six chromones reference standards, including two isolated compounds of 3'-O-angeloylhamaudol and norcimifugin from the extraction of SR, were used to study the fragmentation pathways of chromones. The developed method was effective for characterising the compounds of SR, and the results of the study enriched the understanding of the chemical connotation.

Identification and quantification of nitrofurazone metabolites by ultraperformance liquid chromatography-quadrupole time-of-flight high-resolution mass spectrometry with precolumn derivatization.

PubMed

Zhang, Shuai; Li, PeiPei; Yan, Zhongyong; Long, Ju; Zhang, Xiaojun

2017-03-01

An ultraperformance liquid chromatography-quadrupole time-of-flight high-resolution mass spectrometry method was developed and validated for the determination of nitrofurazone metabolites. Precolumn derivatization with 2,4-dinitrophenylhydrazine and p-dimethylaminobenzaldehyde as an internal standard was used successfully to determine the biomarker 5-nitro-2-furaldehyde. In negative electrospray ionization mode, the precise molecular weights of the derivatives were 320.0372 for the biomarker and 328.1060 for the internal standard (relative error 1.08 ppm). The matrix effect was evaluated and the analytical characteristics of the method and derivatization reaction conditions were validated. For comparison purposes, spiked samples were tested by both internal and external standard methods. The results show high precision can be obtained with p-dimethylaminobenzaldehyde as an internal standard for the identification and quantification of nitrofurazone metabolites in complex biological samples. Graphical Abstract A simplified preparation strategy for biological samples.

Triacylglycerol compositions of sunflower, corn and soybean oils examined with supercritical CO2 ultra-performance convergence chromatography combined with quadrupole time-of-flight mass spectrometry.

PubMed

Gao, Boyan; Luo, Yinghua; Lu, Weiying; Liu, Jie; Zhang, Yaqiong; Yu, Liangli Lucy

2017-03-01

A supercritical CO 2 ultra-performance convergence chromatography (UPC 2 ) system was utilized with a quadrupole time-of-flight mass spectrometry (Q-TOF MS) to examine the triacylglycerol compositions of sunflower, corn and soybean oils. UPC 2 provided an excellent resolution and separation for the triacylglycerols, while the high performance Q-TOF MS system was able to provide the molecular weight and fragment ions information for triacylglycerol compound characterization. A total of 33 triacylglycerols were identified based on their elementary compositions and MS 2 fragment ion profiles, and their levels in the three oils were estimated. The combination of UPC 2 and Q-TOF MS may determine triacylglycerol compositions for oils and fats, and provide sn-position information for fatty acids, which may be important for food nutritional value and stability. Copyright © 2016 Elsevier Ltd. All rights reserved.

Profiling of nonvolatiles in whiskeys using ultra high pressure liquid chromatography quadrupole time-of-flight mass spectrometry (UHPLC-QTOF MS).

PubMed

Collins, Thomas S; Zweigenbaum, Jerry; Ebeler, Susan E

2014-11-15

Commercial samples of 63 American whiskeys, including bourbon whiskeys, Tennessee whiskeys, rye whiskeys and other blended whiskeys were analysed using ultra high pressure liquid chromatography (UHPLC) coupled with quadrupole time-of-flight (QTOF) mass spectrometry (MS). The non-volatile composition of the whiskeys was used to model differences among the samples using discriminant analysis. The blended American whiskeys were readily distinguished from the remaining types. Additionally, most Tennessee whiskeys could be differentiated from bourbon and rye whiskeys. Similarly, younger (<4 years old) and older (>8 years old) whiskeys could be separated. The compounds important for differentiating among these whiskeys included wood derived phenolic compounds, lignan derived compounds and several C8 and larger lipids. A number of additional compounds differentiated the whiskeys but could not be identified using MS and MS/MS data alone. Copyright © 2014 Elsevier Ltd. All rights reserved.

Multi-constituent determination and fingerprint analysis of Scutellaria indica L. using ultra high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry.

PubMed

Liang, Xianrui; Zhao, Cui; Su, Weike

2015-11-01

An ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry method integrating multi-constituent determination and fingerprint analysis has been established for quality assessment and control of Scutellaria indica L. The optimized method possesses the advantages of speediness, efficiency, and allows multi-constituents determination and fingerprint analysis in one chromatographic run within 11 min. 36 compounds were detected, and 23 of them were unequivocally identified or tentatively assigned. The established fingerprint method was applied to the analysis of ten S. indica samples from different geographic locations. The quality assessment was achieved by using principal component analysis. The proposed method is useful and reliable for the characterization of multi-constituents in a complex chemical system and the overall quality assessment of S. indica. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

High-throughput and direct measurement of androgen levels using turbulent flow chromatography liquid chromatography-triple quadrupole mass spectrometry (TFC-LC-TQMS) to discover chemicals that modulate dihydrotestosterone production in human prostate cancer cells.

PubMed

Kang, Kyungsu; Peng, Lei; Jung, Yu-Jin; Kim, Joo Yeon; Lee, Eun Ha; Lee, Hee Ju; Kim, Sang Min; Sung, Sang Hyun; Pan, Cheol-Ho; Choi, Yongsoo

2018-02-01

To develop a high-throughput screening system to measure the conversion of testosterone to dihydrotestosterone (DHT) in cultured human prostate cancer cells using turbulent flow chromatography liquid chromatography-triple quadrupole mass spectrometry (TFC-LC-TQMS). After optimizing the cell reaction system, this method demonstrated a screening capability of 103 samples, including 78 single compounds and 25 extracts, in less than 12 h without manual sample preparation. Consequently, fucoxanthin, phenethyl caffeate, and Curcuma longa L. extract were validated as bioactive chemicals that inhibited DHT production in cultured DU145 cells. In addition, naringenin boosted DHT production in DU145 cells. The method can facilitate the discovery of bioactive chemicals that modulate the DHT production, and four phytochemicals are potential candidates of nutraceuticals to adjust DHT levels in male hormonal dysfunction.

Qualitative and quantitative analysis of poly(amidoamine) dendrimers in an aqueous matrix by liquid chromatography-electrospray ionization-hybrid quadrupole/time-of-flight mass spectrometry (LC-ESI-QTOF-MS).

PubMed

Uclés, A; Ulaszewska, M M; Hernando, M D; Ramos, M J; Herrera, S; García, E; Fernández-Alba, A R

2013-07-01

This work introduces a liquid chromatography-electrospray ionization-hybrid quadrupole/time-of-flight mass spectrometry (LC-ESI-QTOF-MS)-based method for qualitative and quantitative analysis of poly(amidoamine) (PAMAM) dendrimers of generations 0 to 3 in an aqueous matrix. The multiple charging of PAMAM dendrimers generated by means of ESI has provided key advantages in dendrimer identification by assignation of charge state through high resolution of isotopic clusters. Isotopic distribution in function of abundance of isotopes (12)C and (13)C yielded valuable and complementarity data for confident characterization. A mass accuracy below 3.8 ppm for the most abundant isotopes (diagnostic ions) provided unambiguous identification of PAMAM dendrimers. Validation of the LC-ESI-QTOF-MS method and matrix effect evaluation enabled reliable and reproducible quantification. The validation parameters, limits of quantification in the range of 0.012 to 1.73 μM, depending on the generation, good linear range (R > 0.996), repeatability (RSD < 13.4%), and reproducibility (RSD < 10.9%) demonstrated the suitability of the method for the quantification of dendrimers in aqueous matrices (water and wastewater). The added selectivity, achieved by multicharge phenomena, represents a clear advantage in screening aqueous mixtures due to the fact that the matrix had no significant effect on ionization, with what is evidenced by an absence of sensitivity loss in most generations of PAMAM dendrimers. Fig Liquid chromatography-electrospray ionization-hybrid quadrupole/time of flight mass spectrometry (LC-ESI-QTOF-MS) based method for qualitative and quantitative analysis of PAMAM dendrimers in aqueous matrix.

Miniaturized GC/MS instrumentation for in situ measurements: micro gas chromatography coupled with miniature quadrupole array and paul ion trap mass spectrometers

NASA Technical Reports Server (NTRS)

Holland, P.; Chutjian, A.; Darrach, M.; Orient, O.

2002-01-01

Miniaturized chemical instrumentation is needed for in situ measurements in planetary exploration and other spaceflight applications where factors such as reduction in payload requirements and enhanced robustness are important. In response to this need, we are 'continuing to develop miniaturized GC/MS instrumentation which combines chemical separations by gas chromatography (GC) with mass spectrometry (MS) to provide positive identification of chemical compounds in complex mixtures of gases, such as those found in the International Space Station's cabin atmosphere. Our design approach utilizes micro gas chromatography components coupled with either a miniature quadrupole mass spectrometer array (QMSA) or compact, high-resolution Paul ion trap.

INTERLABORATORY COMPARISON OF MASS SPECTROMETRIC METHODS FOR LEAD ISOTOPES AND TRACE ELEMENTS IN NIST SRM 1400 BONE ASH

EPA Science Inventory

The results of an interlaboratory comparison are reported for he lead isotope composition and for trace element concentrations in NIST SRM 1400 Bone Ash obtained using quadrupole and magnetic-sector inductively coupled plasma mass spectrometry (ICP-MS) and (for the Pb isotopes on...

Comprehensive two-dimensional gas chromatography in combination with rapid scanning quadrupole mass spectrometry in perfume analysis.

PubMed

Mondello, Luigi; Casillia, Alessandro; Tranchida, Peter Quinto; Dugo, Giovanni; Dugo, Paola

2005-03-04

Single column gas chromatography (GC) in combination with a flame ionization detector (FID) and/or a mass spectrometer is routinely employed in the determination of perfume profiles. The latter are to be considered medium to highly complex matrices and, as such, can only be partially separated even on long capillaries. Inevitably, several monodimensional peaks are the result of two or more overlapping components, often hindering reliable identification and quantitation. The present investigation is based on the use of a comprehensive GC (GC x GC) method, in vacuum outlet conditions, for the near to complete resolution of a complex perfume sample. A rapid scanning quadrupole mass spectrometry (qMS) system, employed for the assignment of GC x GC peaks, supplied high quality mass spectra. The validity of the three-dimensional (3D) GC x GC-qMS application was measured and compared to that of GC-qMS analysis on the same matrix. Peak identification, in all applications, was achieved through MS spectra library matching and the interactive use of linear retention indices (LRI).

Simultaneous determination of 3-monochloropropane-1,2-diol and acrylamide in food by gas chromatography-triple quadrupole mass spectrometry with coupled column separation.

PubMed

Xu, Xiao-min; He, Hua-li; Zhu, Yan; Feng, Liang; Ying, Ying; Huang, Bai-fen; Shen, Hai-tao; Han, Jian-long; Ren, Yi-ping

2013-01-14

Both 3-monochloropropane-1,2-diol (3-MCPD) and acrylamide are contaminants found in heat-processed foods and their related products. A quantitative method was developed for the simultaneous determination of both contaminants in food by gas chromatography-triple quadrupole mass spectrometry (GC-MS/MS). The analytes were purified and extracted by the matrix solid-phase dispersion extraction (MSPDE) technique with Extrelut NT. A coupled column (a 3 m Innowax combined with a 30 m DB-5 ms) was developed to separate both compounds efficiently without derivatization. Triple quadrupole mass spectrometry in multiple reaction monitoring mode (MRM) was applied to suppress matrix interference and obtain good sensitivity in the determination of both analytes. The limit of detection (LOD) in the sample matrix was 5 μg kg(-1) for 3-MCPD or acrylamide. The average recoveries for 3-MCPD and acrylamide in different food matrices were 90.5-107% and 81.9-95.7%, respectively, with the intraday relative standard deviations (RSDs) of 5.6-13.5% and 5.3-13.4%, respectively. The interday RSDs were 6.1-12.6% for 3-MCPD and were 5.0-12.8% for acrylamide. Both contaminants were found in samples of bread, fried chips, fried instant noodles, soy sauce, and instant noodle flavoring. Neither 3-MCPD nor acrylamide was detected in the samples of dairy products (solid or liquid samples) and non-fried instant noodles. Copyright © 2012 Elsevier B.V. All rights reserved.

An improved pseudotargeted metabolomics approach using multiple ion monitoring with time-staggered ion lists based on ultra-high performance liquid chromatography/quadrupole time-of-flight mass spectrometry.

PubMed

Wang, Yang; Liu, Fang; Li, Peng; He, Chengwei; Wang, Ruibing; Su, Huanxing; Wan, Jian-Bo

2016-07-13

Pseudotargeted metabolomics is a novel strategy integrating the advantages of both untargeted and targeted methods. The conventional pseudotargeted metabolomics required two MS instruments, i.e., ultra-high performance liquid chromatography/quadrupole-time- of-flight mass spectrometry (UHPLC/Q-TOF MS) and UHPLC/triple quadrupole mass spectrometry (UHPLC/QQQ-MS), which makes method transformation inevitable. Furthermore, the picking of ion pairs from thousands of candidates and the swapping of the data between two instruments are the most labor-intensive steps, which greatly limit its application in metabolomic analysis. In the present study, we proposed an improved pseudotargeted metabolomics method that could be achieved on an UHPLC/Q-TOF/MS instrument operated in the multiple ion monitoring (MIM) mode with time-staggered ion lists (tsMIM). Full scan-based untargeted analysis was applied to extract the target ions. After peak alignment and ion fusion, a stepwise ion picking procedure was used to generate the ion lists for subsequent single MIM and tsMIM. The UHPLC/Q-TOF tsMIM MS-based pseudotargeted approach exhibited better repeatability and a wider linear range than the UHPLC/Q-TOF MS-based untargeted metabolomics method. Compared to the single MIM mode, the tsMIM significantly increased the coverage of the metabolites detected. The newly developed method was successfully applied to discover plasma biomarkers for alcohol-induced liver injury in mice, which indicated its practicability and great potential in future metabolomics studies. Copyright © 2016 Elsevier B.V. All rights reserved.

Rapid and sensitive determination of major polyphenolic components in Euphoria longana Lam. seeds using matrix solid-phase dispersion extraction and UHPLC with hybrid linear ion trap triple quadrupole mass spectrometry.

PubMed

Rathore, Atul S; Sathiyanarayanan, L; Deshpande, Shreekant; Mahadik, Kakasaheb R

2016-11-01

A rapid and sensitive method for the extraction and determination of four major polyphenolic components in Euphoria longana Lam. seeds is presented for the first time based on matrix solid-phase dispersion extraction followed by ultra high performance liquid chromatography with hybrid triple quadrupole linear ion trap mass spectrometry. Matrix solid-phase dispersion method was designed for the extraction of Euphoria longana seed constituents and compared with microwave-assisted extraction and ultrasonic-assisted extraction methods. An Ultra high performance liquid chromatography with hybrid triple quadrupole linear ion-trap mass spectrometry method was developed for quantitative analysis in multiple-reaction monitoring mode in negative electrospray ionization. The chromatographic separation was accomplished using an ACQUITY UPLC BEH C 18 (2.1 mm × 50 mm, 1.7 μm) column with gradient elution of 0.1% aqueous formic acid and 0.1% formic acid in acetonitrile. The developed method was validated with acceptable linearity (r 2 > 0.999), precision (RSD ≤ 2.22%) and recovery (RSD ≤ 2.35%). The results indicated that matrix solid-phase dispersion produced comparable extraction efficiency compared with other methods nevertheless was more convenient and time-saving with reduced requirements on sample and solvent volumes. The proposed method is rapid and sensitive in providing a promising alternative for extraction and comprehensive determination of active components for quality control of Euphoria longana products. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Metabolic profile of naringenin in the stomach and colon using liquid chromatography/electrospray ionization linear ion trap quadrupole-Orbitrap-mass spectrometry (LC-ESI-LTQ-Orbitrap-MS) and LC-ESI-MS/MS.

PubMed

Orrego-Lagarón, Naiara; Vallverdú-Queralt, Anna; Martínez-Huélamo, Miriam; Lamuela-Raventos, Rosa M; Escribano-Ferrer, Elvira

2016-02-20

Several biological activities (antioxidant, anti-inflammatory, anticarcinogenic) are attributed to naringenin (NAR)-a predominant flavonoid of citrus fruit and tomato-despite its low bioavailability after ingestion. NAR undergoes extensive metabolism when crossing the gastrointestinal tract, resulting in enteric, hepatic and microbial metabolites, some of them with recognized beneficial effects on human health. This study sought to provide new insights into the metabolism of NAR in regions of the gastrointestinal tract where it has been less studied: the stomach and colon. With this purpose, liquid chromatography coupled with an electrospray ionization hybrid linear ion trap quadrupole Orbitrap mass spectrometry technique (LC-ESI-LTQ-Orbitrap-MS) was used for an accurate identification of NAR metabolites, and liquid chromatography/electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) on a triple quadrupole was used for their identification and quantification. The combination of both analytical techniques provided a broader metabolic profile of NAR. As far as we know, this is the first in-depth metabolic profiling study of NAR in the stomach of mice. Three of the metabolites determined using the LC-LTQ-Orbitrap could not be identified by LC-ESI-MS/MS in stomach perfusion samples: apigenin, 3-(4-hydroxyphenyl) propionic acid and phloroglucinol. The number of colonic metabolites determined using the LTQ-Orbitrap-MS was more than twice the number identified by LC-ESI-MS/MS. Copyright © 2015 Elsevier B.V. All rights reserved.

Chiral separation and chemical profile of Dengzhan Shengmai by integrating comprehensive with multiple heart-cutting two-dimensional liquid chromatography coupled with quadrupole time-of-flight mass spectrometry.

PubMed

Sheng, Ning; Zheng, Hao; Xiao, Yao; Wang, Zhe; Li, Menglin; Zhang, Jinlan

2017-09-29

Chemical profile for Chinese medicine formulas composed of several herbs is always a challenge due to a big array of small molecules with high chemical diversity so much as isomers. The present paper develops a feasible strategy to characterize and identify complex chemical constituents of a four-herb traditional Chinese medicine formula, Denzhan Shenmai (DZSM) by integrating comprehensive two-dimensional liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (LC×LC-qTOF-MS) with multiple heart-cutting two-dimensional liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (MHC-qTOF-MS). DZSM was separated by C8×C18 HPLC column system for comprehensive two-dimensional liquid chromatography system and 283 compounds most of which belonged to phenolic acid, flavonoid, saponin and lignan families were characterized and identified within 75min. Some isomers and compounds at low level were analyzed on C8×Chiral HPLC column system for multiple heart-cutting two-dimensional liquid chromatography system with 1D and 2D optimized gradient elution program. These 1D cutting fractions were successively separated on 2D chiral chromatographic column under extended the 2D gradient elution time from 30s to 5.0min. 12 pairs of isomer compounds were separated with good resolution. The combination of LC×LC and MHC system provides a powerful technique for global chemical profiling of DZSM and provided feasible strategy for other complex systems. Copyright © 2017 Elsevier B.V. All rights reserved.

Capabilities of different liquid chromatography tandem mass spectrometry systems in determining pesticide residues in food. Application to estimate their daily intake.

PubMed

Soler, Carla; James, K J; Picó, Yolanda

2007-07-20

Three different liquid chromatography-mass spectrometry (LC-MS) instruments equipped with triple quadrupole (QqQ), quadrupole ion trap (QIT) and quadrupole-time-of-flight (QqTOF), suitable to carry out tandem mass spectrometry, were examined to determine pesticide residues in food. Twelve pesticides (acrinathrin, bupirimate, buprofezin, cyproconazole, lambda-cyhalothrin, fluvalinate, hexaflumuron, kresoxim-methyl, propanil, pyrifenox, pyriproxyfen and tebufenpyrad) and six matrices (oranges, strawberries, cherries, peaches, apricots and pears) were taken as model. The comparison was focused on two aspects: the quantitative, covering sensitivity, precision and accuracy as well as the qualitative, checking the possibility to identify any metabolite present in the samples, which were not targeted in the methods. The extraction was carried out using pressurized liquid extraction (PLE) with ethyl acetate and acid alumina. Recoveries were over 70 % for all the analytes. Repeatabilities were better for the QqQ (5-12%) than for QIT (6-15%) and for QqTOF (14-19%). QqQ offered a linear dynamic range of at least three orders of magnitude, whereas those of QIT and QqTOF were two and one orders of magnitude, respectively. QqQ reached at least 20-fold higher sensitivity than QIT and QqTOF. However, the QqQ failed to identify non-target compounds. QIT and QqTOF were able to successfully identify the metabolite of bupirimate, ethirimol. Application to monitor the content in fruits, taken from agricultural cooperatives, and to calculate the estimated daily intake (EDI) to establish if there is any difference of toxicological interest is also reported.

Lysophosphatidylcholine and amide as metabolites for detecting alzheimer disease using ultrahigh-performance liquid chromatography-quadrupole time-of-flight mass spectrometry-based metabonomics.

PubMed

Cui, Yu; Liu, Xiuqin; Wang, Maoqing; Liu, Liyan; Sun, Xiaohong; Ma, Lan; Xie, Wei; Wang, Chao; Tang, Sisi; Wang, Decai; Wu, Qunhong

2014-10-01

Alzheimer disease (AD) can be diagnosed by clinical and neuropsychologic tests and at autopsy, but there are no simple effective diagnostic methods for detecting biomarkers in patients at early stages of cognitive impairment. Early metabolic alterations that may facilitate AD diagnosis have not been thoroughly explored. We applied a nontargeted metabonomic approach using ultrahigh-performance liquid chromatography-quadrupole time-of-flight mass spectrometry to analyze serum and urine samples from 46 patients with AD and 36 healthy controls. Metabolite profiles were processed using multivariate analysis to identify potential metabolites, which were further confirmed using tandem mass spectrometry. Ultrahigh-performance liquid chromatography mass spectrometry methods were additionally used to quantify potentially important biomarkers. Independent samples were then selected to validate the identified biomarkers. There was a clear separation between healthy controls and AD patients; AD patient samples had disordered amino acid and phospholipid metabolism and dysregulated palmitic amide. Receiver operator characteristic curve and quantification suggested that palmitic amide, lysophosphatidylcholine (LysoPC, 18:0), LysoPC(18:2), L-glutamine, and 5-L-glutamylglycine were the optimal metabolites. In addition, areas under the curve from the palmitic amide, LysoPC(18:2), and 5-L-glutamylglycine in the validation study were 0.714, 0.996, and 0.734, respectively. These data elucidate the metabolic alterations associated with AD and suggest new biomarkers for AD diagnosis, thereby permitting early intervention designed to prevent disease progression.

Bioinformatics Pertinent to Lipid Analysis in Biological Samples.

PubMed

Ma, Justin; Arbelo, Ulises; Guerra, Yenifer; Aribindi, Katyayini; Bhattacharya, Sanjoy K; Pelaez, Daniel

2017-01-01

Electrospray ionization mass spectrometry has revolutionized the way lipids are studied. In this work, we present a tutorial for analyzing class-specific lipid spectra obtained from a triple quadrupole mass spectrometer. The open-source software MZmine 2.21 is used, coupled with LIPID MAPS databases. Here, we describe the steps for lipid identification, ratiometric quantification, and briefly address the differences to the analyses when using direct infusion versus tandem liquid chromatography-mass spectrometry (LC-MS). We also provide a tutorial and equations for quantification of lipid amounts using synthetic lipid standards and normalization to a protein amount.

Mass spectrometry. [review of techniques

NASA Technical Reports Server (NTRS)

Burlingame, A. L.; Kimble, B. J.; Derrick, P. J.

1976-01-01

Advances in mass spectrometry (MS) and its applications over the past decade are reviewed in depth, with annotated literature references. New instrumentation and techniques surveyed include: modulated-beam MS, chromatographic MS on-line computer techniques, digital computer-compatible quadrupole MS, selected ion monitoring (mass fragmentography), and computer-aided management of MS data and interpretation. Areas of application surveyed include: organic MS and electron impact MS, field ionization kinetics, appearance potentials, translational energy release, studies of metastable species, photoionization, calculations of molecular orbitals, chemical kinetics, field desorption MS, high pressure MS, ion cyclotron resonance, biochemistry, medical/clinical chemistry, pharmacology, and environmental chemistry and pollution studies.

On the isobaric space of 25-hydroxyvitamin D in human serum: potential for interferences in liquid chromatography/tandem mass spectrometry, systematic errors and accuracy issues.

PubMed

Qi, Yulin; Geib, Timon; Schorr, Pascal; Meier, Florian; Volmer, Dietrich A

2015-01-15

Isobaric interferences in human serum can potentially influence the measured concentration levels of 25-hydroxyvitamin D [25(OH)D], when low resolving power liquid chromatography/tandem mass spectrometry (LC/MS/MS) instruments and non-specific MS/MS product ions are employed for analysis. In this study, we provide a detailed characterization of these interferences and a technical solution to reduce the associated systematic errors. Detailed electrospray ionization Fourier transform ion cyclotron resonance (FTICR) high-resolution mass spectrometry (HRMS) experiments were used to characterize co-extracted isobaric components of 25(OH)D from human serum. Differential ion mobility spectrometry (DMS), as a gas-phase ion filter, was implemented on a triple quadrupole mass spectrometer for separation of the isobars. HRMS revealed the presence of multiple isobaric compounds in extracts of human serum for different sample preparation methods. Several of these isobars had the potential to increase the peak areas measured for 25(OH)D on low-resolution MS instruments. A major isobaric component was identified as pentaerythritol oleate, a technical lubricant, which was probably an artifact from the analytical instrumentation. DMS was able to remove several of these isobars prior to MS/MS, when implemented on the low-resolution triple quadrupole mass spectrometer. It was shown in this proof-of-concept study that DMS-MS has the potential to significantly decrease systematic errors, and thus improve accuracy of vitamin D measurements using LC/MS/MS. Copyright © 2014 John Wiley & Sons, Ltd.

Systematic forensic toxicological analysis by liquid-chromatography-quadrupole-time-of-flight mass spectrometry in serum and comparison to gas chromatography-mass spectrometry.

PubMed

Grapp, Marcel; Kaufmann, Christoph; Streit, Frank; Binder, Lutz

2018-06-01

Comprehensive screening procedures for psychoactive agents in body fluids are an essential task in clinical and forensic toxicology. With the continuous emergence and adaption of new psychoactive substances (NPS) keeping a screening method up to date is challenging. To meet these demands, hyphenated high-resolution mass spectrometry has gained interest as extensive and expandable screening approach. Here we present a comprehensive method for systematic toxicological analysis of serum by liquid chromatography-quadrupole-time-of-flight mass spectrometry (LC-QTOF-MS) with data independent acquisition. The potential of this method was demonstrated by analysis of 247 authentic serum- and 12 post-mortem femoral blood samples. Thus 950 compounds, comprising 185 different drugs and metabolites could be identified. For the detected substances, including pharmaceutical substances, illicit drugs as well as NPS, serum concentrations were confirmed ranging from traces to toxic values indicating the capability for forensic toxicological requirements. Positive identification of drugs was achieved by accurate mass measurement (±5ppm for [M+H] + ; ±10ppm for [M-H] - ), retention time (±0.35min), isotopic pattern match (less than 10 m/z RMS [ppm]), isotope match intensity (less than 20% RMS) and the presence of at least two fragment ions. The LC-QTOF-MS procedure was shown to be superior to serum screening by GC-MS, since 240% (335 versus 141) more drugs were identified in serum samples compared to GC-MS. Copyright © 2018 Elsevier B.V. All rights reserved.

Real-time measurement of sodium chloride in individual aerosol particles by mass spectrometry

NASA Technical Reports Server (NTRS)

Sinha, M. P.; Friedlander, S. K.

1985-01-01

The method of particle analysis by mass spectrometry has been applied to the quantitative measurement of sodium chloride in individual particles on a real-time basis. Particles of known masses are individually introduced, in the form of a beam, into a miniature Knudsen cell oven (1600 K). The oven is fabricated from rhenium metal sheet (0.018 mm thick) and is situated in the ion source of a quadrupole mass spectrometer. A particle once inside the oven is trapped and completely volatilized; this overcomes the problem of partial volatilization due to particles bouncing from the filament surface. Individual particles are thermally volatilized and ionized inside the rhenium oven, and produce discrete sodium ion pulses whose intensities are measured with the quadrupole mass spectrometer. An ion pulse width of several milliseconds (4-12 ms) is found for particles in the mass range 1.3 x 10 to the -13th to 5.4 x 10 to the -11th g. The sodium ion intensity is found to be proportional to the particle mass to the 0.86-power. The intensity distribution for monodisperse aerosol particles possesses a geometric standard deviation of 1.09, showing that the method can be used for the determination of the mass distribution function with good resolution in a polydisperse aerosol.

Quantification of 2'-deoxy-2'-β-fluoro-4'-azidocytidine in rat and dog plasma using liquid chromatography-quadrupole time-of-flight and liquid chromatography-triple quadrupole mass spectrometry: Application to bioavailability and pharmacokinetic studies.

PubMed

Peng, Youmei; Cheng, Tiefeng; Dong, Lihong; Zhang, Yuhai; Chen, Xiaojing; Jiang, Jinhua; Zhang, Jingmin; Guo, Xiaohe; Guo, Mintong; Chang, Junbiao; Wang, Qingduan

2014-09-01

2'-Deoxy-2'-β-fluoro-4'-azidocytidine (FNC) is a novel pyrimidine analog that inhibits not only the replication of the hepatitis B virus (HBV), hepatitis C virus (HCV) and HIV but also the replication of lamivudine-resistant HBV, 4'-azidocytidine or 2'-β-methylcytidine-resistant HCV, and nucleoside reverse-transcriptase inhibitor-resistant HIV variants. The present study was undertaken to evaluate the absolute oral bioavailability of FNC in rats and the pharmacokinetic properties of FNC after intragastric administration of single and multiple doses in rats and dogs. A sensitive high-performance liquid chromatography tandem quadrupole time-of-flight mass spectrometry (HPLC/Q-TOF MS) method and a reliable high-performance liquid chromatography tandem triple quadrupole mass spectrometry (HPLC/QqQ MS/MS) method were established for the determination of FNC in the rat and dog plasmas, respectively. The sample preparation involved a protein-precipitation method with methanol after the addition of lamivudine as an internal standard. FNC was analyzed by LC using a YMC-Pack Pro C18 column (150mm×4.6mm, 3μm) with methanol (containing 0.3% formic acid): 10mM ammonium acetate (containing 0.3% formic acid, pH 2.8) (35:65, v/v) as the mobile phase. Both mass spectrometers were equipped with an electrospray ionization interface in the positive-ion mode. The linear range was from 2.00 to 2000.00ngmL(-1) in rat plasma and 0.50 to 400.00ngmL(-1) in dog plasma. The intraday and interday precision were less than 10.55%, and the accuracy was in the range of -5.86 to 5.13%. The mean recoveries were greater than 82.70% and 82.97% for FNC and IS, respectively. The HPLC/Q-TOF MS and HPLC/QqQ MS/MS methods were both successfully applied in the pharmacokinetic studies of FNC in rats and dogs. Copyright © 2014 Elsevier B.V. All rights reserved.

A liquid chromatography method with single quadrupole mass spectrometry for quantitative determination of indomethacin in maternal plasma and urine of pregnant patients

PubMed Central

Wang, Xiaoming; Vernikovskaya, Daria I.; Nanovskaya, Tatiana N.; Rytting, Erik; Hankins, Gary D.V.; Ahmed, Mahmoud S.

2013-01-01

A liquid chromatography with single quadrupole mass spectrometry method was developed for the quantitative determination of indomethacin in the maternal plasma and urine of pregnant patients under treatment. A deuterium-labeled isotope of indomethacin (d4-indomethacin) was used as an internal standard. The maternal plasma and urine samples were acidified with 1.0 MHCl then extracted with chloroform to achieve the extraction recovery range of 94% to 104% with variation less than 11%. Chromatographic separation was achieved by a Waters Symmetry C18 column with isocratic elution of 0.05% (v/v) formic acid aqueous solution and acetonitrile (47:53, v/v). An in-source fragmentation was applied on the single quadrupole mass spectrometer equipped with an electrospray ionization source at positive mode. The LC-ESI-MS quantification was performed in the selected ion monitoring mode targeting ions at m/z 139 for indomethacin and m/z 143 for its internal standard. The calibration curves were linear in the concentration ranges between 14.8 and 2.97×103 ng/mL for plasma samples and between 10.5 and 4.21×103 ng/mL for urine samples. The relative standard deviation of this method was less than 8% for intra- and inter-day assays, and the accuracy ranged between 90% and 108%. PMID:23474812

Investigating the presence of omeprazole in waters by liquid chromatography coupled to low and high resolution mass spectrometry: degradation experiments.

PubMed

Boix, C; Ibáñez, M; Sancho, J V; Niessen, W M A; Hernández, F

2013-10-01

Omeprazole is one of the most consumed pharmaceuticals around the world. However, this compound is scarcely detected in urban wastewater and surface water. The absence of this pharmaceutical in the aquatic ecosystem might be due to its degradation in wastewater treatment plants, as well as in receiving water. In this work, different laboratory-controlled degradation experiments have been carried out on surface water in order to elucidate generated omeprazole transformation products (TPs). Surface water spiked with omeprazole was subjected to hydrolysis, photo-degradation under both sunlight and ultraviolet radiation and chlorination. Analyses by liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (LC-QTOF MS) permitted identification of up to 17 omeprazole TPs. In a subsequent step, the TPs identified were sought in surface water and urban wastewater by LC-QTOF MS and by LC coupled to tandem mass spectrometry with triple quadrupole. The parent omeprazole was not detected in any of the samples, but four TPs were found in several water samples. The most frequently detected compound was OTP 5 (omeprazole sulfide), which might be a reasonable candidate to be included in monitoring programs rather than the parent omeprazole. Copyright © 2013 John Wiley & Sons, Ltd.

Dual enzyme activities assay by quantitative electrospray ionization quadrupole-time-of-flight mass spectrometry.

PubMed

Cai, Tingting; Zhang, Li; Wang, Haoyang; Zhang, Jing; Wang, Rong; Zhang, Yurong; Guo, Yinlong

2012-01-01

A practical and rapid method based on electrospray ionization quadrupole-time of flight mass spectrometry (ESI-Q-ToF MS) was developed for detecting activities of both acetylcholinesterase IAChEI and glutathione S-transferase (GST). The simultaneous study of these two enzyme activities is significant for studying human bio-functions, especially for those who take in toxic compounds and have a risk of disease. Here, the enzyme activities were represented by the conversion of enzymatic substrates and determined by quantitatively analyzing enzymatic substrates. Different internal standards were used to quantify each enzymatic substrate and the good linearity of calibration curves demonstrated the feasibility of the internal standards. The Michaelis-Menten constants (Km) of both GST and AChE were measured by this method and were consistent with values previously reported. Furthermore, we applied this approach to detect GST and AChE activities of whole bloods from four deceased and healthy people. The variation in enzyme activity was in accord with information from gas chromatography mass spectrometry [GC/MS). The screening of AChE and GST provided reliable results and strong forensic evidence. This method offers an alternative choice for detecting enzyme activities and is anticipated to have wide applications in pharmaceutical research and prevention in toxic compounds.

Metabolic Profiling of Hoodia, Chamomile, Terminalia Species and Evaluation of Commercial Preparations Using Ultrahigh-Performance Liquid Chromatography Quadrupole-Time-of-Flight Mass Spectrometry.

PubMed

Avula, Bharathi; Wang, Yan-Hong; Isaac, Giorgis; Yuk, Jimmy; Wrona, Mark; Yu, Kate; Khan, Ikhlas A

2017-11-01

Ultrahigh-performance liquid chromatography quadrupole-time-of-flight mass spectrometry (UHPLC-QToF-MS) profiling was used for the identification of marker compounds and generation of metabolic patterns that could be interrogated using chemometric modeling software. UHPLC-QToF-MS was used to generate comprehensive fingerprints of three botanicals ( Hoodia, Terminalia , and chamomile), each having different classes of compounds. Detection of a broad range of ions was carried out in full scan mode in both positive and negative modes over the range m/z 100-1700 using high-resolution mass spectrometry. Multivariate statistical analysis was used to extract relevant chemical information from the data to easily differentiate between Terminalia species, chamomile varieties, and quality control of Hoodia products. Using nontargeted analysis, identification of 37 compounds contributed to the differences between Terminalia species, 26 flavonoids were identified to show the differences between German and Roman chamomile, and 43 pregnane glycosides were identified from Hoodia gordonii samples. The UHPLC-QToF-MS-based chemical fingerprinting with principal component analysis was able to correctly distinguish botanicals and their commercial products. This work can be used as a basis to assure the quality of botanicals and commercial products. Georg Thieme Verlag KG Stuttgart · New York.

Simultaneous qualitative and quantitative analysis of flavonoids and alkaloids from the leaves of Nelumbo nucifera Gaertn. using high-performance liquid chromatography with quadrupole time-of-flight mass spectrometry.

PubMed

Guo, Yujie; Chen, Xi; Qi, Jin; Yu, Boyang

2016-07-01

A reliable method, combining qualitative analysis by high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry and quantitative assessment by high-performance liquid chromatography with photodiode array detection, has been developed to simultaneously analyze flavonoids and alkaloids in lotus leaf extracts. In the qualitative analysis, a total of 30 compounds, including 12 flavonoids, 16 alkaloids, and two proanthocyanidins, were identified. The fragmentation behaviors of four types of flavone glycoside and three types of alkaloid are summarized. The mass spectra of four representative components, quercetin 3-O-glucuronide, norcoclaurine, nuciferine, and neferine, are shown to illustrate their fragmentation pathways. Five pairs of isomers were detected and three of them were distinguished by comparing the elution order with reference substances and the mass spectrometry data with reported data. In the quantitative analysis, 30 lotus leaf samples from different regions were analyzed to investigate the proportion of eight representative compounds. Quercetin 3-O-glucuronide was found to be the predominant constituent of lotus leaf extracts. For further discrimination among the samples, hierarchical cluster analysis, and principal component analysis, based on the areas of the eight quantitative peaks, were carried out. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Screening and identification of steroidal saponins from Anemarrhena asphodeloides employing UPLC tandem triple quadrupole linear ion trap mass spectrometry.

PubMed

Xia, Yong-Gang; Guo, Xin-Dong; Liang, Jun; Yang, Bing-You; Kuang, Hai-Xue

2017-09-01

This study presents a practical and valid strategy for the screening and structural characterization of Anemarrhena asphodeloides Bge steroidal saponins (SSs) using ultra-high performance liquid chromatography coupled with triple quadrupole linear ion trap mass spectrometry. The whole analytical protocols integrate four-step procedures in the positive mode: (1) rational deduction of mass fragmentation pathways of A. asphodeloides SSs; (2) untargeted screening of potential A. asphodeloides SSs by multiple-ion monitoring-information-dependent-acquiring-enhanced product ion (MIM-IDA-EPI) scan through reverse phase liquid chromatography; (3) comprehensive construction of an ammoniated precursor ion database by combining untargeted MIM-IDA-EPI scans and data literature; and (4) structural interpretation of targeted A. asphodeloides SSs using MIM-IDA-EPI and multiple reaction monitoring (MRM)-IDA-EPI with an energy-resolved technique. The protocols were used to analyze SSs in A. asphodeloides; of the 87 detected SSs that were unambiguously characterized or tentatively identified, 19 compounds were the first to be reported from A. asphodeloides and 13 ones were characterized as potential new compounds. Accuracy of the analytical procedure was demonstrated by structural identification of three SSs by NMR spectroscopy. The proposed schemes hold an excellent promise in the structural prediction and interpretation of complex SSs from plant medicines by mass spectrometry. Copyright © 2017 Elsevier Inc. All rights reserved.

Widely-targeted quantitative lipidomics methodology by supercritical fluid chromatography coupled with fast-scanning triple quadrupole mass spectrometry.

PubMed

Takeda, Hiroaki; Izumi, Yoshihiro; Takahashi, Masatomo; Paxton, Thanai; Tamura, Shohei; Koike, Tomonari; Yu, Ying; Kato, Noriko; Nagase, Katsutoshi; Shiomi, Masashi; Bamba, Takeshi

2018-05-03

Lipidomics, the mass spectrometry-based comprehensive analysis of lipids, has attracted attention as an analytical approach to provide novel insight into lipid metabolism and to search for biomarkers. However, an ideal method for both comprehensive and quantitative analysis of lipids has not been fully developed. Herein, we have proposed a practical methodology for widely-targeted quantitative lipidome analysis using supercritical fluid chromatography fast-scanning triple-quadrupole mass spectrometry (SFC/QqQMS) and theoretically calculated a comprehensive lipid multiple reaction monitoring (MRM) library. Lipid classes can be separated by SFC with a normal phase diethylamine-bonded silica column with high-resolution, high-throughput, and good repeatability. Structural isomers of phospholipids can be monitored by mass spectrometric separation with fatty acyl-based MRM transitions. SFC/QqQMS analysis with an internal standard-dilution method offers quantitative information for both lipid class and individual lipid molecular species in the same lipid class. Additionally, data acquired using this method has advantages including reduction of misidentification and acceleration of data analysis. Using the SFC/QqQMS system, alteration of plasma lipid levels in myocardial infarction-prone rabbits to the supplementation of eicosapentaenoic acid was first observed. Our developed SFC/QqQMS method represents a potentially useful tool for in-depth studies focused on complex lipid metabolism and biomarker discovery. Published under license by The American Society for Biochemistry and Molecular Biology, Inc.

Quantification of short- and medium-chain chlorinated paraffins in environmental samples by gas chromatography quadrupole time-of-flight mass spectrometry.

PubMed

Gao, Wei; Wu, Jing; Wang, Yawei; Jiang, Guibin

2016-06-24

Chlorinated paraffins (CPs) are technical products produced and used in bulk for a number of purposes. However, the analysis of CPs is challenging, as they are complex mixtures of compounds and isomers. We herein report the development of an analytical method for the analysis of short-chain CPs (SCCPs) and medium-chain CPs (MCCPs) using quadrupole time-of-flight high-resolution mass spectrometry (GC-NCI-qTOF-HRMS). This method employs gas chromatography with a chemical ionization source working in negative mode. The linear relationship between chlorination and the CP total response factors was applied to quantify the CP content and the congener group distribution patterns. In a single injection, 24 SCCP formula groups and 24 MCCP formula groups were quantified. Extraction of accurate masses using qTOF-HRMS allowed the SCCPs and MCCPs to be distinguished, with interference from other chemicals (e.g., PCBs) being largely avoided. The SCCP and MCCP detection limits were 24-81ng/mL and 27-170ng/mL, respectively. Comparison of the obtained results with analytical results from gas chromatography coupled with electron capture negative ionization low-resolution mass spectrometry (GC-ECNI-LRMS) indicate that the developed technique is a more accurate and convenient method for the analysis of CPs in samples from a range of matrices. Copyright © 2016 Elsevier B.V. All rights reserved.

Design and performance of an instrument for electron impact tandem mass spectrometry and action spectroscopy of mass/charge selected macromolecular ions stored in RF ion trap*

NASA Astrophysics Data System (ADS)

Ranković, Milos Lj.; Giuliani, Alexandre; Milosavljević, Aleksandar R.

2016-06-01

A new apparatus was designed, coupling an electron gun with a linear quadrupole ion trap mass spectrometer, to perform m/ z (mass over charge) selected ion activation by electron impact for tandem mass spectrometry and action spectroscopy. We present in detail electron tracing simulations of a 300 eV electron beam inside the ion trap, design of the mechanical parts, electron optics and electronic circuits used in the experiment. We also report examples of electron impact activation tandem mass spectra for Ubiquitin protein, Substance P and Melittin peptides, at incident electron energies in the range from 280 eV to 300 eV.

Detection of trace ink compounds in erased handwritings using electrospray-assisted laser desorption ionization mass spectrometry.

PubMed

Kao, Yi-Ying; Cheng, Sy-Chyi; Cheng, Chu-Nian; Shiea, Jentaie; Ho, Hsiu-O

2014-06-01

Writings made with erasable pens on paper surfaces can either be rubbed off with an eraser or rendered invisible by changing the temperature of the ink. However, trace ink compounds still remain in the paper fibers even after rubbing or rendering. The detection of these ink compounds from erased handwritings will be helpful in knowing the written history of the paper. In this study, electrospray-assisted laser desorption ionization/mass spectrometry was used to characterize trace ink compounds remaining in visible and invisible ink lines. The ink compounds were desorbed from the paper surface by irradiating the handwritings with a pulsed laser beam; the desorbed analytes were subsequently ionized in an electrospray plume and detected by a quadrupole time-of-flight mass spectrometry mass analyzer. Because of the high spatial resolution of the laser beam, electrospray-assisted laser desorption ionization/mass spectrometry analysis resulted in minimal damage to the sample documents. Copyright © 2014 John Wiley & Sons, Ltd.

Nontarget analysis of polar contaminants in freshwater sediments influenced by pharmaceutical industry using ultra-high-pressure liquid chromatography-quadrupole time-of-flight mass spectrometry.

PubMed

Terzic, Senka; Ahel, Marijan

2011-02-01

A comprehensive analytical procedure for a reliable identification of nontarget polar contaminants in aquatic sediments was developed, based on the application of ultra-high-pressure liquid chromatography (UHPLC) coupled to hybrid quadrupole time-of-flight mass spectrometry (QTOFMS). The procedure was applied for the analysis of freshwater sediment that was highly impacted by wastewater discharges from the pharmaceutical industry. A number of different contaminants were successfully identified owing to the high mass accuracy of the QTOFMS system, used in combination with high chromatographic resolution of UHPLC. The major compounds, identified in investigated sediment, included a series of polypropylene glycols (n=3-16), alkylbenzene sulfonate and benzalkonium surfactants as well as a number of various pharmaceuticals (chlorthalidone, warfarin, terbinafine, torsemide, zolpidem and macrolide antibiotics). The particular advantage of the applied technique is its capability to detect less known pharmaceutical intermediates and/or transformation products, which have not been previously reported in freshwater sediments. Copyright © 2010 Elsevier Ltd. All rights reserved.

Quantification of proteins in urine samples using targeted mass spectrometry methods.

PubMed

Khristenko, Nina; Domon, Bruno

2015-01-01

Numerous clinical proteomics studies are focused on the development of biomarkers to improve either diagnostics for early disease detection or the monitoring of the response to the treatment. Although, a wealth of biomarker candidates are available, their evaluation and validation in a true clinical setup remains challenging. In biomarkers evaluation studies, a panel of proteins of interest are systematically analyzed in a large cohort of samples. However, in spite of the latest progresses in mass spectrometry, the consistent detection of pertinent proteins in high complex biological samples is still a challenging task. Thus, targeted LC-MS/MS methods are better suited for the systematic analysis of biomarkers rather than shotgun approaches. This chapter describes the workflow used to perform targeted quantitative analyses of proteins in urinary samples. The peptides, as surrogates of the protein of interest, are commonly measured using a triple quadrupole mass spectrometers operated in selected reaction monitoring (SRM) mode. More recently, the advances in targeted LC-MS/MS analysis based on parallel reaction monitoring (PRM) performed on a quadrupole-orbitrap instrument have allowed to increase the specificity and selectivity of the measurements.

Quality classification of Spanish olive oils by untargeted gas chromatography coupled to hybrid quadrupole-time of flight mass spectrometry with atmospheric pressure chemical ionization and metabolomics-based statistical approach.

PubMed

Sales, C; Cervera, M I; Gil, R; Portolés, T; Pitarch, E; Beltran, J

2017-02-01

The novel atmospheric pressure chemical ionization (APCI) source has been used in combination with gas chromatography (GC) coupled to hybrid quadrupole time-of-flight (QTOF) mass spectrometry (MS) for determination of volatile components of olive oil, enhancing its potential for classification of olive oil samples according to their quality using a metabolomics-based approach. The full-spectrum acquisition has allowed the detection of volatile organic compounds (VOCs) in olive oil samples, including Extra Virgin, Virgin and Lampante qualities. A dynamic headspace extraction with cartridge solvent elution was applied. The metabolomics strategy consisted of three different steps: a full mass spectral alignment of GC-MS data using MzMine 2.0, a multivariate analysis using Ez-Info and the creation of the statistical model with combinations of responses for molecular fragments. The model was finally validated using blind samples, obtaining an accuracy in oil classification of 70%, taking the official established method, "PANEL TEST", as reference. Copyright © 2016 Elsevier Ltd. All rights reserved.

Polyphenolic profile of butterhead lettuce cultivar by ultrahigh performance liquid chromatography coupled online to UV-visible spectrophotometry and quadrupole time-of-flight mass spectrometry.

PubMed

Viacava, Gabriela E; Roura, Sara I; López-Márquez, Diana M; Berrueta, Luis A; Gallo, Blanca; Alonso-Salces, Rosa M

2018-09-15

In the present study, the butterhead lettuce cultivar was analyzed by ultrahigh performance liquid chromatography (UHPLC) coupled online to diode array detection (DAD), electrospray ionization (ESI) and quadrupole time-of-flight mass spectrometry (QToF/MS) in the positive and negative ion mode in order to characterize its polyphenolic profile for the first time. The instrument acquisition mode MS E was used to collect automatic and simultaneous information of exact mass at high and low collision energies of precursor ions as well as other ions produced as a result of their fragmentation. One hundred eleven phenolic compounds were identified in the acidified hydromethanolic extract of freeze-dried leaves of butterhead lettuce cultivar: 40 hydroxycinnamic acid derivatives, 21 hydroxybenzoic acid derivatives, 2 hydroxyphenylacetic acid derivatives, 18 flavonols, 9 flavones, one flavanone, 7 coumarins, one hydrolysable tannin and 12 lignans. Forty-seven of these compounds have been tentatively identified for the first time in lettuce. Copyright © 2018 Elsevier Ltd. All rights reserved.

Urinary metabolomic profiling in rats exposed to dietary di(2-ethylhexyl) phthalate (DEHP) using ultra-performance liquid chromatography quadrupole time-of-flight tandem mass spectrometry (UPLC/Q-TOF-MS).

PubMed

Dong, Xinwen; Zhang, Yunbo; Dong, Jin; Zhao, Yue; Guo, Jipeng; Wang, Zhanju; Liu, Mingqi; Na, Xiaolin; Wang, Cheng

2017-07-01

Di(2-ethylhexyl) phthalate (DEHP) is an omnipresent environmental chemical with widespread nonoccupational human exposure through multiple ways. Although considerable efforts have been invested to investigate mechanisms of DEHP toxicity, the key metabolic biomarkers of DEHP toxicity remain to be identified. The aim of this study was to assess the urinary metabonomics of dietary DEHP in rats using the technique of ultra-performance liquid chromatography quadrupole time-of-flight tandem mass spectrometry (UPLC/Q-TOF-MS). Fourteen female Wistar rats were divided into two groups and given increasing dietary doses of DEHP for 30 consecutive days. The urinary metabolite profile was studied using ultra-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry. Principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA) enabled clusters to be clearly separated. Eleven principal urinary metabolites were identified as contributing to the clusters. The clusters in the positive electrospray ionization (ESI) mode were xanthurenic acid, kynurenic acid, nonate, N6-methyladenosine, and L-isoleucyl-L-proline. The clusters in the negative ESI mode were hippuric acid, tetrahydrocortisol, citric acid, phenylpropionylglycine, cPA(18:2(9Z, 12Z)/0:0), and LysoPC(14:1(9Z)). The urinary metabonomic changes indicated that exposure to dietary DEHP can affect energy-related metabolism, liver and renal function, fatty acid metabolism, and cause DNA damage in rats. The findings of this study on the urinary metabolites and metabolic pathways of DEHP may form the basis for future studies on the mechanisms of toxicity of this commonly found environmental chemical.

Development and Application of an MSALL-Based Approach for the Quantitative Analysis of Linear Polyethylene Glycols in Rat Plasma by Liquid Chromatography Triple-Quadrupole/Time-of-Flight Mass Spectrometry.

PubMed

Zhou, Xiaotong; Meng, Xiangjun; Cheng, Longmei; Su, Chong; Sun, Yantong; Sun, Lingxia; Tang, Zhaohui; Fawcett, John Paul; Yang, Yan; Gu, Jingkai

2017-05-16

Polyethylene glycols (PEGs) are synthetic polymers composed of repeating ethylene oxide subunits. They display excellent biocompatibility and are widely used as pharmaceutical excipients. To fully understand the biological fate of PEGs requires accurate and sensitive analytical methods for their quantitation. Application of conventional liquid chromatography-tandem mass spectrometry (LC-MS/MS) is difficult because PEGs have polydisperse molecular weights (MWs) and tend to produce multicharged ions in-source resulting in innumerable precursor ions. As a result, multiple reaction monitoring (MRM) fails to scan all ion pairs so that information on the fate of unselected ions is missed. This Article addresses this problem by application of liquid chromatography-triple-quadrupole/time-of-flight mass spectrometry (LC-Q-TOF MS) based on the MS ALL technique. This technique performs information-independent acquisition by allowing all PEG precursor ions to enter the collision cell (Q2). In-quadrupole collision-induced dissociation (CID) in Q2 then effectively generates several fragments from all PEGs due to the high collision energy (CE). A particular PEG product ion (m/z 133.08592) was found to be common to all linear PEGs and allowed their total quantitation in rat plasma with high sensitivity, excellent linearity and reproducibility. Assay validation showed the method was linear for all linear PEGs over the concentration range 0.05-5.0 μg/mL. The assay was successfully applied to the pharmacokinetic study in rat involving intravenous administration of linear PEG 600, PEG 4000, and PEG 20000. It is anticipated the method will have wide ranging applications and stimulate the development of assays for other pharmaceutical polymers in the future.

Gas-phase ion chemistry and organic chemistry-the story of a hybrid six sector mass spectrometer--the "AutoSpec 6F".

PubMed

Gerbaux, Pascal; Lamote, Luc; Van Haverbeke, Yves; Flammang, Robert; Brown, Jeffrey M

2012-01-01

The AutoSpec 6F mass spectrometer is a large, floor standing instrument comprising a pair of commercial EBE geometry (AutoSpec) mass spectrometers coupled in series to provide an hybrid EBE-EBE configuration, (E and B being respectively electrostatic and magnetic sectors.) It was designed in close collaboration between Professor R. Flammang and VG Analytical in Manchester, UK. It was equipped with five collision cells and allowed the recording of high energy CID (collision induced dissociation), MIKES (mass analyzed ion kinetic energy spectrometry) and NRMS (neutralization re-ionization mass spectrometry) data as well as consecutive MSn analyses. The field-free regions between sectors allowed the study of unimolecular decomposition products from long-lived metastable ions. The mass spectrometer became even more versatile when an RF-only quadrupole collision cell was installed between the second and the third electric sector. This allowed the study of associative ion/molecule reactions in the low kinetic energy regime. Bimolecular chemical reactions were performed inside the quadrupole cell when a neutral reagent was introduced and the reaction products were analyzed by high energy CID in the downstream sectors. This paper tells the history and summarizes the capabilities of this versatile instrument.

Identification of N-nitrosamines in treated drinking water using nanoelectrospray ionization high-field asymmetric waveform ion mobility spectrometry with quadrupole time-of-flight mass spectrometry.

PubMed

Zhao, Yuan Yuan; Liu, Xin; Boyd, Jessica M; Qin, Feng; Li, Jianjun; Li, Xing-Fang

2009-01-01

We report a nanoelectrospray ionization (nESI) with high-field asymmetric waveform ion mobility spectrometry (FAIMS) and tandem mass spectrometry (MS-MS) method for determination of small molecules of m/z 50 to 200 and its potential application in environmental analysis. Integration of nESI with FAIMS and MS-MS combines the advantages of these three techniques into one method. The nESI provides efficient sample introduction and ionization and allows for collection of multiple data from only microliters of samples. The FAIMS provides rapid separation, reduces or eliminates background interference, and improves the signal-to-noise ratio as much as 10-fold over nESI-MS-MS. The tandem quadrupole time-of-flight MS detection provides accurate mass and mass spectral measurements for structural identification. Characteristics of FAIMS compensation voltage (CV) spectra of seven nitrosamines, N-nitrosodimethylamine (NDMA), N-nitrosomethylethylamine (NMEA), N-nitrosodiethylamine (NDEA), N-nitrosodi-n-propylamine (NDPA), N-nitrosodi-n-butylamine (NDBA), N-nitrosopiperidine (NPip), and N-nitrosopyrrolidine (NPyr), were analyzed. The optimal CV of the nitrosamines (at DV -4000 V) were: -1.6 V, NDBA; 2.6 V, NDPA; 6.6 V, NPip; 8.8 V, NDEA; 13.2 V, NPyr; 14.4 V, NMEA; and 19.4 V, NDMA. Fragmentation patterns of the seven nitrosamines in the nESI-FAIMS-MS-MS were also obtained. The specific CV and MS-MS spectra resulted in positive identification of NPyr and NPip in a treated water sample, demonstrating the potential application of this technique in environmental analysis.

Fragmentation pathways of 2-substituted pyrrole derivatives using electrospray ionization ion trap and electrospray ionization quadrupole time-of-flight mass spectrometry.

PubMed

Liang, Xianrui; Guo, Zili; Yu, Chuanming

2013-10-30

Pyrrole derivatives are of considerable importance and are present in a wide range of natural products and used extensively in drug discovery. Fragmentation pathway studies play an important role in the structural identification of pyrrole derivatives. As a part of our ongoing work on heterocycles, fragmentation pathways of 2-substituted pyrrole derivatives were investigated by mass spectrometry (MS). Twelve pyrrole derivatives were synthesized and analyzed. Low-resolution fragmentation ions of all the compounds were generated by ion trap mass spectrometry (ITMS(n) ) with an electrospray ionization (ESI) source in positive mode. Hybrid quadrupole time-of-flight mass spectrometry (QTOFMS) was used to determine the elemental compositions of the resultant product ions. The side-chain substituents at the 2-position influence the fragmentation pathways. Typical losses of H2 O, aldehydes and pyrrole moieties from the [M + H](+) ion are observed for the compounds with side chains bearing aromatic groups at the 2-position of the pyrrole. However, losses of H2 O, alcohols and C3 H6 are the main cleavage pathways for compounds 6 and 12 with nonphenyl-substituted side chains at the 2-position. Typical fragmentation mechanisms of 2-substituted pyrrole derivatives are proposed and elucidated based on the observations of ITMS(n) and QTOFMS spectra. The results showed that the fragmentation pathways were remarkably influenced by the side-chain substituents at the 2-position of pyrrole. This investigation should have value in the structural identification of this series of molecules or compounds with similar structures. Copyright © 2013 John Wiley & Sons, Ltd.

Use of a Designed Peptide Array To Infer Dissociation Trends for Nontryptic Peptides in Quadrupole Ion Trap and Quadrupole Time-of-Flight Mass Spectrometry

DOE PAGES

Gaucher, Sara P.; Morrow, Jeffrey A.; Faulon, Jean-Loup M.

2007-09-14

Observed peptide gas-phase fragmentation patterns are a complex function of many variables. In order to systematically probe this phenomenon, an array of 40 peptides was synthesized for study. The array of sequences was designed to hold certain variables (peptide length) constant and randomize or balance others (peptide amino acid distribution and position). A high-quality tandem mass spectrometry (MS/MS) data set was acquired for each peptide for all observed charge states on multiple MS instruments, quadrupole-time-of-flight and quadrupole ion trap. The data were analyzed as a function of total charge state and number of mobile protons. Previously known dissociation trends weremore » observed, validating our approach. In addition, the general influence of basic amino acids on dissociation could be determined because, in contrast to the more widely studied tryptic peptides, the amino acids H, K, and R were positionally distributed. Interestingly, our results suggest that cleavage at all basic amino acids is suppressed when a mobile proton is available. Cleavage at H becomes favored only under conditions where a partially mobile proton is present, a caveat to the previously reported trend of enhanced cleavage at H. In conclusion, all acquired data were used as a benchmark to determine how well these sequences would have been identified in a database search using a common algorithm, Mascot.« less

The use of ultra-high pressure liquid chromatography with tandem mass spectrometric detection of analysis of agrochemical residues and mycotoxines in food - challenges and applications

USDA-ARS?s Scientific Manuscript database

In the field of food contaminant analysis, the most significant development of recent years has been the integration of ultra-high pressure liquid chromatography (UHPLC), coupled to tandem quadrupole mass spectrometry (MS/MS), into analytical applications. In this review, we describe the emergence o...

Recent applications of gas chromatography with high-resolution mass spectrometry.

PubMed

Špánik, Ivan; Machyňáková, Andrea

2018-01-01

Gas chromatography coupled to high-resolution mass spectrometry is a powerful analytical method that combines excellent separation power of gas chromatography with improved identification based on an accurate mass measurement. These features designate gas chromatography with high-resolution mass spectrometry as the first choice for identification and structure elucidation of unknown volatile and semi-volatile organic compounds. Gas chromatography with high-resolution mass spectrometry quantitative analyses was previously focused on the determination of dioxins and related compounds using magnetic sector type analyzers, a standing requirement of many international standards. The introduction of a quadrupole high-resolution time-of-flight mass analyzer broadened interest in this method and novel applications were developed, especially for multi-target screening purposes. This review is focused on the development and the most interesting applications of gas chromatography coupled to high-resolution mass spectrometry towards analysis of environmental matrices, biological fluids, and food safety since 2010. The main attention is paid to various approaches and applications of gas chromatography coupled to high-resolution mass spectrometry for non-target screening to identify contaminants and to characterize the chemical composition of environmental, food, and biological samples. The most interesting quantitative applications, where a significant contribution of gas chromatography with high-resolution mass spectrometry over the currently used methods is expected, will be discussed as well. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Gas-phase structural characterization of neuropeptides Y Y1 receptor antagonists using mass spectrometry: Orbitrap vs triple quadrupole.

PubMed

Silva, Eduarda M P; Varandas, Pedro A M M; Melo, Tânia; Barros, Cristina; Alencastre, Inês S; Barreiros, Luísa; Domingues, Pedro; Lamghari, Meriem; Domingues, M Rosário M; Segundo, Marcela A

2018-03-20

Collision induced dissociation of triple quadrupole mass spectrometer (CID-QqQ) and high-energy collision dissociation (HCD) of Orbitrap were compared for four neuropeptides Y Y1 (NPY Y1) receptor antagonists and showed similar qualitative fragmentation and structural information. Orbitrap high resolution and high mass accuracy HCD fragmentation spectra allowed unambiguous identification of product ions in the range 0.04-4.25 ppm. Orbitrap mass spectrometry showed abundant analyte-specific product ions also observed on CID-QqQ. These results show the suitability of these product ions for use in quantitative analysis by MRM mode. In addition, it was found that all compounds could be determined at levels >1 μg L -1 using the QqQ instrument and that the detection limits for this analyzer ranged from 0.02 to 0.6 μg L -1 . Overall, the results obtained from experiments acquired in QqQ show a good agreement with those acquired from the Orbitrap instrument allowing the use of this relatively inexpensive technique (QqQ) for accurate quantification of these compounds in clinical and academic applications. Copyright © 2018 Elsevier B.V. All rights reserved.

Comparative metabolites profiles of osthole in normal and osteoporosis rats using liquid chromatography quadrupole time-of-flight mass spectrometry.

PubMed

Wang, Nani; Wang, Xuping; Zhang, Yang; Zhang, Qiaoyan; Xu, Pingcui; Xin, Hailiang; Wu, Renjie; Shou, Dan; Qin, Luping

2018-05-30

Osthole is a derivative of coumnarin, which has been used to treat several diseases, including osteoporosis. To investigate the metabolite profile of osthole in osteoporosis rats was utilized to understand its underlying mechanisms of its anti-osteoporosis effect. In this study, plasma samples were collected from normal and osteoporosis rats after oral administration of osthole and analyzed to identify the metabolites of osthole by high performance liquid chromatography quadrupole time-of-flight mass spectrometry. By comparing the molecular weight and MS fragmentation of the metabolites with those of parent drug and reference standards, a total of 36 metabolites in plasma were identified. Demethylation, hydroxylation, hydroxymethylene loss and reduction, and subsequent glucuronidation, methylation and sulfation were the major metabolic pathways of osthole in both normal and osteoporosis rats. A specific hydration metabolic pathway was found in osteoporosis rats. These results provided a meaningful basis for studying the underlying mechanism of the anti-osteoporosis effect of osthole. Copyright © 2018 Elsevier B.V. All rights reserved.

Characterization of a novel oxyfluorfen-degrading bacterial strain Chryseobacterium aquifrigidense and its biochemical degradation pathway.

PubMed

Zhao, Huanhuan; Xu, Jun; Dong, Fengshou; Liu, Xingang; Wu, Yanbing; Wu, Xiaohu; Zheng, Yongquan

2016-08-01

Persistent use of the diphenyl ether herbicides oxyfluorfen may seriously increase the health risks and ecological safety problems. A newly bacterium R-21 isolated from active soil was able to degrade and utilize oxyfluorfen as the sole carbon source. R-21 was identified as Chryseobacterium aquifrigidense by morphology, physiobiochemical characteristics, and genetic analysis. Under the optimum cultural conditions (pH 6.9, temperature 33.4 °C, and inoculum size 0.2 g L(-1)), R-21 could degrade 92.1 % of oxyfluorfen at 50 mg L(-1) within 5 days. During oxyfluorfen degradation, six metabolites were detected and identified by atmospheric pressure gas chromatography coupled to quadrupole-time of flight mass spectrometry and ultra-performance liquid chromatography coupled to quadrupole-time of flight mass spectrometry, and a plausible degradation pathway was deduced. Strain R-21 is a promising potential in bioremediation of oxyfluorfen-contaminated environments.

Liquid chromatography quadrupole time-of-flight mass spectrometry determination of six pharmaceuticals in vegetal biota. Uptake study in Lavandula dentata.

PubMed

Barreales-Suárez, Sofía; Callejón-Mochón, Manuel; Azoulay, Stéphane; Bello-López, Miguel Ángel; Fernández-Torres, Rut

2018-05-01

A procedure based on microwave assisted extraction for the determination of 6 pharmaceuticals in samples of Lavandula dentata, Salicornia ramosissima and Juncus sp. by liquid chromatography-quadrupole time of flight mass spectrometry (LC-QTOF/MS) was optimized and validated. Best results were obtained using microwave assisted extraction of 1.0g of homogeneous lyophilized samples and 5mL of a mixture ACN:H 2 O (1:1 v/v) as extracting solvent. Analytical recoveries ranged from 60 to 107% with relative standard deviation (RSD) lower than 15%. Limits of quantitation (LOQ) for the 6 pharmaceuticals flumequine (FLM), carbamazepine (CBZ), ciprofloxacin (CPR), enrofloxacin (ENR), diclofenac (DCL), and ibuprofen (IBU) were in the range 20.8-125ngg -1 . The method was satisfactory applied for an uptake study in Lavandula dentata samples finding quantifying concentrations of FLM and CBZ in roots, leaf and stem. Copyright © 2017 Elsevier B.V. All rights reserved.

Characterization of organic gunshot residues in lead-free ammunition using a new sample collection device for liquid chromatography-quadrupole time-of-flight mass spectrometry.

PubMed

Benito, Sandra; Abrego, Zuriñe; Sánchez, Alicia; Unceta, Nora; Goicolea, M Aranzazu; Barrio, Ramón J

2015-01-01

The identification of characteristic organic gunshot residues (OGSR) provides conclusive evidence in the elucidation of elemental profiles when lead-free ammunition is fired. OGSR also prevents false negatives. Toward this aim, a quick and efficient method based on liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-QTOF) was developed to detect and identify 18 gunpowder additives in gunshot residues (GSR). The unequivocal identification of target analytes was assured by using MS/MS mode. Swabs were compared with home-modified tape lift supports covered with a PTFE layer to determine the better sampling technique. The modified tape lift provided better extraction recoveries and enabled the analysis of inorganic and organic GSR simultaneously. The developed method was applied to the analysis of GSR from four different lead-free ammunitions. Diphenylamine and its nitrated degradation products and centralites were identified in all samples, providing strong evidence of GSR. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Characterization of metabolic profile of honokiol in rat feces using liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry and (13)C stable isotope labeling.

PubMed

Dong, Yinfeng; Tang, Minghai; Song, Hang; Li, Rong; Wang, Chunyu; Ye, Haoyu; Qiu, Neng; Zhang, Yongkui; Chen, Lijuan; Wei, Yuquan

2014-03-15

As fecal excretion is one of important routes of elimination of drugs and their metabolites, it is indispensable to investigate the metabolites in feces for more comprehensive information on biotransformation in vivo. In this study, a sensitive and reliable approach based on ultra-performance liquid chromatography/quadrupole-time-of-flight-mass spectrometry (UHPLC-Q-TOF-MS) was applied to characterize the metabolic profile of honokiol in rat feces after the administration of an equimolar mixture of honokiol and [(13)C6]-labeled honokiol. Totally 42 metabolites were discovered and tentatively identified in rat feces samples, 26 metabolites were first reported, including two novel classes of metabolites, methylated and dimeric metabolites of honokiol. Moreover, this study provided basic comparative data on the metabolites in rat plasma, feces and urine, which gave better understanding of the metabolic fate of honokiol in vivo. Copyright © 2014 Elsevier B.V. All rights reserved.

Determination of diffusion coefficients of hydrogen and deuterium in Zr-2.5%Nb pressure tube material using hot vacuum extraction-quadrupole mass spectrometry

NASA Astrophysics Data System (ADS)

Shrivastava, Komal Chandra; Kulkarni, A. S.; Ramanjaneyulu, P. S.; Sunil, Saurav; Saxena, M. K.; Singh, R. N.; Tomar, B. S.; Ramakumar, K. L.

2015-06-01

The diffusion coefficients of hydrogen and deuterium in Zr-2.5%Nb alloy were measured in the temperature range 523 to 673 K, employing hot vacuum extraction-quadrupole mass spectrometry (HVE-QMS). One end of the Zr-2.5%Nb alloy specimens was charged electrolytically with the desired hydrogen isotope. After annealing at different temperatures for a predetermined time, the specimens were cut into thin slices, which were analyzed for their H2/D2 content using the HVE-QMS technique. The depth profile data were fitted into the equation representing the solution of Fick's second law of diffusion. The activation energy of hydrogen/deuterium diffusion was obtained from the Arrhenius relation between the diffusion coefficient and temperature. The temperature dependent diffusion coefficient can be represented as DH = 1.41 × 10-7 exp(-36,000/RT) and DD = 6.16 × 10-8 exp(-35,262/RT) for hydrogen and deuterium, respectively.

Evaluation of gas chromatography-tandem quadrupole mass spectrometry for the determination of organochlorine pesticides in fats and oils.

PubMed

Patel, Katan; Fussell, Richard J; Hetmanski, Mike; Goodall, David M; Keely, Brendan J

2005-03-18

A gas chromatography-tandem quadrupole mass spectrometry multi-residue method for the analysis of 19 organochlorine pesticides in fats and oils has been developed. Gel permeation chromatography was employed to remove lipid material prior to GC-MS/MS analysis. Average recoveries of the pesticides spiked at 10 and 50 microg kg(-1) into fish oil, pork fat, olive oil and hydrogenated vegetable oil were typically in the range 70-110% with relative standard deviations generally less than 10%. Calculated limits of detection are between 0.1 and 2.0 microg kg(-1) and results obtained for the analysis of proficiency test materials are in good agreement with assigned values. The higher selectivity of the GC-MS/MS compared to electron capture detection and GC-MS in selective ion monitoring mode allowed unambiguous identification and confirmation of all the target pesticides at low microg kg(-1) levels in fats and oils in a single analysis.

Synthesis and analytical follow-up of the mineralization of a new fluorosurfactant prototype.

PubMed

Peschka, M; Fichtner, N; Hierse, W; Kirsch, P; Montenegro, E; Seidel, M; Wilken, R D; Knepper, T P

2008-08-01

Fluorinated surfactants have become essential in numerous technical applications due to their unparalleled effectiveness and efficiency. The environmental persistence of the non-biodegradable perfluorinated alkyl moiety has become a matter of concern. Therefore, it was searched for new molecules with chemically stable fluorinated end groups which can be microbially transformed into labile fluorinated substances. One prototype substance, 10-(trifluoromethoxy)decane-1-sulfonate, has shown biomineralization. Monitoring the formation of metabolites over time elucidated the mechanism of biotransformation. Analysis was performed utilizing liquid chromatography-single quadrupole mass spectrometry (LC-MS) and quadrupole-time of flight tandem mass spectrometry (QqTOF-MS). It was possible to distinguish between two major degradation pathways of the fluorinated alkylsulfonate derivative: (i) a desulfonation and subsequent oxidation and degradation of the alkyl chain being predominant and (ii) an insertion of oxygen with a subsequent cleavage and degradation of the molecule. The utilized trifluoromethoxy-endgroup resulted in instable trifluoromethanol after degradation of the alkyl chain, which led to a high degree of mineralization of the molecule.

Analysis of 100 pharmaceuticals and their degradates in water samples by liquid chromatography/quadrupole time-of-flight mass spectrometry.

PubMed

Ferrer, Imma; Thurman, E Michael

2012-10-12

A straightforward methodology for the chromatographic separation and accurate mass identification of 100 pharmaceuticals including some of their degradation products was developed using liquid chromatography/quadrupole time-of-flight mass spectrometry (LC/Q-TOF-MS). A table compiling the protonated or deprotonated exact masses for all compounds, as well as the exact mass of several fragment ions obtained by MS-MS is included. Excellent chromatographic separation was achieved by using 3.5 μm particle size columns and a slow and generic 30-min gradient. Isobaric and isomeric compounds (same nominal mass and same exact mass, respectively) were distinguished by various methods, including chromatography separation, MS-MS fragmentation, and isotopic signal identification. Method reporting limits of detection ranged from 1 to 1000 ng/L, after solid-phase extraction of 100mL aqueous samples. The methodology was successfully applied to the analysis of surface water impacted by wastewater effluent by identifying many of the pharmaceuticals and metabolites included in the list. Examples are given for some of the most unusual findings in environmental samples. This paper is meant to serve as a guide for those doing analysis of pharmaceuticals in environmental samples, by providing exact mass measurements of several well known, as well as newly identified and environmentally relevant pharmaceuticals in water samples. Copyright © 2012 Elsevier B.V. All rights reserved.

Current use of high-resolution mass spectrometry in drug screening relevant to clinical and forensic toxicology and doping control.

PubMed

Ojanperä, Ilkka; Kolmonen, Marjo; Pelander, Anna

2012-05-01

Clinical and forensic toxicology and doping control deal with hundreds or thousands of drugs that may cause poisoning or are abused, are illicit, or are prohibited in sports. Rapid and reliable screening for all these compounds of different chemical and pharmaceutical nature, preferably in a single analytical method, is a substantial effort for analytical toxicologists. Combined chromatography-mass spectrometry techniques with standardised reference libraries have been most commonly used for the purpose. In the last ten years, the focus has shifted from gas chromatography-mass spectrometry to liquid chromatography-mass spectrometry, because of progress in instrument technology and partly because of the polarity and low volatility of many new relevant substances. High-resolution mass spectrometry (HRMS), which enables accurate mass measurement at high resolving power, has recently evolved to the stage that is rapidly causing a shift from unit-resolution, quadrupole-dominated instrumentation. The main HRMS techniques today are time-of-flight mass spectrometry and Orbitrap Fourier-transform mass spectrometry. Both techniques enable a range of different drug-screening strategies that essentially rely on measuring a compound's or a fragment's mass with sufficiently high accuracy that its elemental composition can be determined directly. Accurate mass and isotopic pattern acts as a filter for confirming the identity of a compound or even identification of an unknown. High mass resolution is essential for improving confidence in accurate mass results in the analysis of complex biological samples. This review discusses recent applications of HRMS in analytical toxicology.

Identification and Quantitative Measurements of Chemical Species by Mass Spectrometry

NASA Technical Reports Server (NTRS)

Zondlo, Mark A.; Bomse, David S.

2005-01-01

The development of a miniature gas chromatograph/mass spectrometer system for the measurement of chemical species of interest to combustion is described. The completed system is a fully-contained, automated instrument consisting of a sampling inlet, a small-scale gas chromatograph, a miniature, quadrupole mass spectrometer, vacuum pumps, and software. A pair of computer-driven valves controls the gas sampling and introduction to the chromatographic column. The column has a stainless steel exterior and a silica interior, and contains an adsorbent of that is used to separate organic species. The detection system is based on a quadrupole mass spectrometer consisting of a micropole array, electrometer, and a computer interface. The vacuum system has two miniature pumps to maintain the low pressure needed for the mass spectrometer. A laptop computer uses custom software to control the entire system and collect the data. In a laboratory demonstration, the system separated calibration mixtures containing 1000 ppm of alkanes and alkenes.

Real-time quantitative analysis of H2, He, O2, and Ar by quadrupole ion trap mass spectrometry.

PubMed

Ottens, Andrew K; Harrison, W W; Griffin, Timothy P; Helms, William R

2002-09-01

The use of a quadrupole ion trap mass spectrometer (QITMS) for quantitative analysis of hydrogen and helium as well as of other permanent gases is demonstrated. Like commercial instruments, the customized QITMS uses mass selective instability; however, this instrument operates at a greater trapping frequency and without a buffer gas. Thus, a useable mass range from 2 to over 50 daltons (Da) is achieved. The performance of the ion trap is evaluated using part-per-million (ppm) concentrations of hydrogen, helium, oxygen, and argon mixed into a nitrogen gas stream, as outlined by the National Aeronautics and Space Administration (NASA), which is interested in monitoring for cryogenic fuel leaks within the Space Shuttle during launch preparations. When quantitating the four analytes, relative accuracy and precision were better than the NASA-required minimum of 10% error and 5% deviation, respectively. Limits of detection were below the NASA requirement of 25-ppm hydrogen and 100-ppm helium; those for oxygen and argon were within the same order of magnitude as the requirements. These results were achieved at a fast data recording rate, and demonstrate the utility of the QITMS as a real-time quantitative monitoring device for permanent gas analysis. c. 2002 American Society for Mass Spectrometry.

A new hybrid electrospray Fourier transform mass spectrometer: design and performance characteristics.

PubMed

O'connor, Peter B; Pittman, Jason L; Thomson, Bruce A; Budnik, Bogdan A; Cournoyer, Jason C; Jebanathirajah, Judith; Lin, Cheng; Moyer, Susanne; Zhao, Cheng

2006-01-01

A new hybrid electrospray quadrupole Fourier transform mass spectrometry (FTMS) instrument design is shown and characterized. This instrument involves coupling an electrospray source and mass-resolving quadrupole, ion accumulation, and collision cell linear ion trap system developed by MDS Sciex with a home-built ion guide and ion cyclotron resonance (ICR) cell. The iterative progression of this design is shown. The final design involves a set of hexapole ion guides to transfer the ions from the accumulation/collision trap through the magnetic field gradient and into the cell. These hexapole ion guides are separated by a thin gate valve and two conduction limits to maintain the required <10(-9) mbar vacuum for FTICR. Low-attomole detection limits for a pure peptide are shown, 220 000 resolving power in broadband mode and 820 000 resolving power in narrow-band mode are demonstrated, and mass accuracy in the <2 ppm range is routinely available provided the signal is abundant, cleanly resolved, and internally calibrated. This instrument design provides high experimental flexibility, allowing Q2 CAD, SORI-CAD, IRMPD, and ECD experiments with selected ion accumulation as well as experiments such as nozzle skimmer dissociation. Initial top-down mass spectrometry experiments on a protein is shown using ECD.

Correlation between y-type ions observed in ion trap and triple quadrupole mass spectrometers.

PubMed

Sherwood, Carly A; Eastham, Ashley; Lee, Lik Wee; Risler, Jenni; Vitek, Olga; Martin, Daniel B

2009-09-01

Multiple reaction monitoring mass spectrometry (MRM-MS) is a technique for high-sensitivity targeted analysis. In proteomics, MRM-MS can be used to monitor and quantify a peptide based on the production of expected fragment peaks from the selected peptide precursor ion. The choice of which fragment ions to monitor in order to achieve maximum sensitivity in MRM-MS can potentially be guided by existing MS/MS spectra. However, because the majority of discovery experiments are performed on ion trap platforms, there is concern in the field regarding the generalizability of these spectra to MRM-MS on a triple quadrupole instrument. In light of this concern, many operators perform an optimization step to determine the most intense fragments for a target peptide on a triple quadrupole mass spectrometer. We have addressed this issue by targeting, on a triple quadrupole, the top six y-ion peaks from ion trap-derived consensus library spectra for 258 doubly charged peptides from three different sample sets and quantifying the observed elution curves. This analysis revealed a strong correlation between the y-ion peak rank order and relative intensity across platforms. This suggests that y-type ions obtained from ion trap-based library spectra are well-suited for generating MRM-MS assays for triple quadrupoles and that optimization is not required for each target peptide.

Quantitative Determination of Bioactive Constituents in Noni Juice by High-performance Liquid Chromatography with Electrospray Ionization Triple Quadrupole Mass Spectrometry.

PubMed

Yan, Yongqiu; Lu, Yu; Jiang, Shiping; Jiang, Yu; Tong, Yingpeng; Zuo, Limin; Yang, Jun; Gong, Feng; Zhang, Ling; Wang, Ping

2018-01-01

Noni juice has been extensively used as folk medicine for the treatment of arthritis, infections, analgesic, colds, cancers, and diabetes by Polynesians for many years. Due to the lack of standard scientific evaluation methods, various kinds of commercial Noni juice with different quality and price were available on the market. To establish a sensitive, reliable, and accurate high-performance liquid chromatography with electrospray ionization triple quadrupole mass spectrometry (HPLC-ESI-MS/MS) method for separation, identification, and simultaneous quantitative analysis of bioactive constituents in Noni juice. The analytes and eight batches of commercially available samples from different origins were separated and analyzed by the HPLC-ESI-MS/MS method on an Agilent ZORBAX SB-C 18 (150 mm × 4.6 mm i.d., 5 μm) column using a gradient elution of acetonitrile-methanol-0.05% glacial acetic acid in water (v/v) at a constant flow rate of 0.5 mL/min. Seven components were identification and all of the assay parameters were within the required limits. Components were within the correlation coefficient values ( R 2 ≥ 0.9993) at the concentration ranges tested. The precision of the assay method was <0.91% and the repeatability between 1.36% and 3.31%. The accuracy varied from 96.40% to 103.02% and the relative standard deviations of stability were <3.91%. Samples from the same origin showed similar content while different origins showed significant different result. The developed methods would provide a reliable basis and be useful in the establishment of a rational quality control standard of Noni juice. Separation, identification, and simultaneous quantitative analysis method of seven bioactive constituents in Noni juice is originally developed by high-performance liquid chromatography with electrospray ionization triple quadrupole mass spectrometryThe presented method was successfully applied to the quality control of eight batches of commercially available samples of Noni juiceThis method is simple, sensitive, reliable, accurate, and efficient method with strong specificity, good precision, and high recovery rate and provides a reliable basis for quality control of Noni juice. Abbreviations used: HPLC-ESI-MS/MS: High-performance liquid chromatography with electrospray ionization triple quadrupole mass spectrometry, LOD: Limit of detection, LOQ: Limit of quantitation, S/N: Signal-to-noise ratio, RSD: Relative standard deviations, DP: Declustering potential, CE: Collision energy, MRM: Multiple reaction monitoring, RT: Retention time.

Quantitative Determination of Bioactive Constituents in Noni Juice by High-performance Liquid Chromatography with Electrospray Ionization Triple Quadrupole Mass Spectrometry

PubMed Central

Yan, Yongqiu; Lu, Yu; Jiang, Shiping; Jiang, Yu; Tong, Yingpeng; Zuo, Limin; Yang, Jun; Gong, Feng; Zhang, Ling; Wang, Ping

2018-01-01

Background: Noni juice has been extensively used as folk medicine for the treatment of arthritis, infections, analgesic, colds, cancers, and diabetes by Polynesians for many years. Due to the lack of standard scientific evaluation methods, various kinds of commercial Noni juice with different quality and price were available on the market. Objective: To establish a sensitive, reliable, and accurate high-performance liquid chromatography with electrospray ionization triple quadrupole mass spectrometry (HPLC-ESI-MS/MS) method for separation, identification, and simultaneous quantitative analysis of bioactive constituents in Noni juice. Materials and Methods: The analytes and eight batches of commercially available samples from different origins were separated and analyzed by the HPLC-ESI-MS/MS method on an Agilent ZORBAX SB-C18 (150 mm × 4.6 mm i.d., 5 μm) column using a gradient elution of acetonitrile-methanol-0.05% glacial acetic acid in water (v/v) at a constant flow rate of 0.5 mL/min. Results: Seven components were identification and all of the assay parameters were within the required limits. Components were within the correlation coefficient values (R2 ≥ 0.9993) at the concentration ranges tested. The precision of the assay method was <0.91% and the repeatability between 1.36% and 3.31%. The accuracy varied from 96.40% to 103.02% and the relative standard deviations of stability were <3.91%. Samples from the same origin showed similar content while different origins showed significant different result. Conclusions: The developed methods would provide a reliable basis and be useful in the establishment of a rational quality control standard of Noni juice. SUMMARY Separation, identification, and simultaneous quantitative analysis method of seven bioactive constituents in Noni juice is originally developed by high-performance liquid chromatography with electrospray ionization triple quadrupole mass spectrometryThe presented method was successfully applied to the quality control of eight batches of commercially available samples of Noni juiceThis method is simple, sensitive, reliable, accurate, and efficient method with strong specificity, good precision, and high recovery rate and provides a reliable basis for quality control of Noni juice. Abbreviations used: HPLC-ESI-MS/MS: High-performance liquid chromatography with electrospray ionization triple quadrupole mass spectrometry, LOD: Limit of detection, LOQ: Limit of quantitation, S/N: Signal-to-noise ratio, RSD: Relative standard deviations, DP: Declustering potential, CE: Collision energy, MRM: Multiple reaction monitoring, RT: Retention time. PMID:29576704

Analysis of metal-binding proteins separated by non-denaturating gel electrophoresis using matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS).

PubMed

Becker, J Susanne; Mounicou, Sandra; Zoriy, Miroslav V; Becker, J Sabine; Lobinski, Ryszard

2008-09-15

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) have become established as very efficient and sensitive biopolymer and elemental mass spectrometric techniques for studying metal-binding proteins (metalloproteins) in life sciences. Protein complexes present in rat tissues (liver and kidney) were separated in their native state in the first dimension by blue native gel electrophoresis (BN-PAGE). Essential and toxic metals, such as zinc, copper, iron, nickel, chromium, cadmium and lead, were detected by scanning the gel bands using quadrupole LA-ICP-MS with and without collision cell as a microanalytical technique. Several proteins were identified by using MALDI-TOF-MS together with a database search. For example, on one protein band cut from the BN-PAGE gel and digested with the enzyme trypsin, two different proteins - protein FAM44B and cathepsin B precursor - were identified. By combining biomolecular and elemental mass spectrometry, it was possible to characterize and identify selected metal-binding rat liver and kidney tissue proteins.

Fenofibrate Metabolism in the Cynomolgus Monkey using Ultraperformance Liquid Chromatography-Quadrupole Time-of-Flight Mass Spectrometry-Based MetabolomicsS⃞

PubMed Central

Liu, Aiming; Patterson, Andrew D.; Yang, Zongtao; Zhang, Xinying; Liu, Wei; Qiu, Fayang; Sun, He; Krausz, Kristopher W.; Idle, Jeffrey R.; Gonzalez, Frank J.; Dai, Renke

2009-01-01

Fenofibrate, widely used for the treatment of dyslipidemia, activates the nuclear receptor, peroxisome proliferator-activated receptor α. However, liver toxicity, including liver cancer, occurs in rodents treated with fibrate drugs. Marked species differences occur in response to fibrate drugs, especially between rodents and humans, the latter of which are resistant to fibrate-induced cancer. Fenofibrate metabolism, which also shows species differences, has not been fully determined in humans and surrogate primates. In the present study, the metabolism of fenofibrate was investigated in cynomolgus monkeys by ultraperformance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOFMS)-based metabolomics. Urine samples were collected before and after oral doses of fenofibrate. The samples were analyzed in both positive-ion and negative-ion modes by UPLC-QTOFMS, and after data deconvolution, the resulting data matrices were subjected to multivariate data analysis. Pattern recognition was performed on the retention time, mass/charge ratio, and other metabolite-related variables. Synthesized or purchased authentic compounds were used for metabolite identification and structure elucidation by liquid chromatographytandem mass spectrometry. Several metabolites were identified, including fenofibric acid, reduced fenofibric acid, fenofibric acid ester glucuronide, reduced fenofibric acid ester glucuronide, and compound X. Another two metabolites (compound B and compound AR), not previously reported in other species, were characterized in cynomolgus monkeys. More importantly, previously unknown metabolites, fenofibric acid taurine conjugate and reduced fenofibric acid taurine conjugate were identified, revealing a previously unrecognized conjugation pathway for fenofibrate. PMID:19251819

Gas chromatographic quadrupole time-of-flight full scan high resolution mass spectrometric screening of human urine in antidoping analysis.

PubMed

Abushareeda, Wadha; Lyris, Emmanouil; Kraiem, Suhail; Wahaibi, Aisha Al; Alyazidi, Sameera; Dbes, Najib; Lommen, Arjen; Nielen, Michel; Horvatovich, Peter L; Alsayrafi, Mohammed; Georgakopoulos, Costas

2017-09-15

This paper presents the development and validation of a high-resolution full scan (FS) electron impact ionization (EI) gas chromatography coupled to quadrupole Time-of-Flight mass spectrometry (GC/QTOF) platform for screening anabolic androgenic steroids (AAS) in human urine samples. The World Antidoping Agency (WADA) enlists AAS as prohibited doping agents in sports, and our method has been developed to comply with the qualitative specifications of WADA to be applied for the detection of sports antidoping prohibited substances, mainly for AAS. The method also comprises of the quantitative analysis of the WADA's Athlete Biological Passport (ABP) endogenous steroidal parameters. The applied preparation of urine samples includes enzymatic hydrolysis for the cleavage of the Phase II glucuronide conjugates, generic liquid-liquid extraction and trimethylsilyl (TMS) derivatization steps. Tandem mass spectrometry (MS/MS) acquisition was applied on few selected ions to enhance the specificity and sensitivity of GC/TOF signal of few compounds. The full scan high resolution acquisition of analytical signal, for known and unknown TMS derivatives of AAS provides the antidoping system with a new analytical tool for the detection designer drugs and novel metabolites, which prolongs the AAS detection, after electronic data files' reprocessing. The current method is complementary to the respective liquid chromatography coupled to mass spectrometry (LC/MS) methodology widely used to detect prohibited molecules in sport, which cannot be efficiently ionized with atmospheric pressure ionization interface. Copyright © 2017 Elsevier B.V. All rights reserved.

A rapid and reliable method for Pb isotopic analysis of peat and lichens by laser ablation-quadrupole-inductively coupled plasma-mass spectrometry for biomonitoring and sample screening.

PubMed

Kylander, M E; Weiss, D J; Jeffries, T E; Kober, B; Dolgopolova, A; Garcia-Sanchez, R; Coles, B J

2007-01-16

An analytical protocol for rapid and reliable laser ablation-quadrupole (LA-Q)- and multi-collector (MC-) inductively coupled plasma-mass spectrometry (ICP-MS) analysis of Pb isotope ratios ((207)Pb/(206)Pb and (208)Pb/(206)Pb) in peats and lichens is developed. This technique is applicable to source tracing atmospheric Pb deposition in biomonitoring studies and sample screening. Reference materials and environmental samples were dry ashed and pressed into pellets for introduction by laser ablation. No binder was used to reduce contamination. LA-MC-ICP-MS internal and external precisions were <1.1% and <0.3%, respectively, on both (207)Pb/(206)Pb and (208)Pb/(206)Pb ratios. LA-Q-ICP-MS internal precisions on (207)Pb/(206)Pb and (208)Pb/(206)Pb ratios were lower with values for the different sample sets <14.3% while external precisions were <2.9%. The level of external precision acquired in this study is high enough to distinguish between most modern Pb sources. LA-MC-ICP-MS measurements differed from thermal ionisation mass spectrometry (TIMS) values by 1% or less while the accuracy obtained using LA-Q-ICP-MS compared to solution MC-ICP-MS was 3.1% or better using a run bracketing (RB) mass bias correction method. Sample heterogeneity and detector switching when measuring (208)Pb by Q-ICP-MS are identified as sources of reduced analytical performance.

New Potential Biomarker for Methasterone Misuse in Human Urine by Liquid Chromatography Quadrupole Time of Flight Mass Spectrometry.

PubMed

Zhang, Jianli; Lu, Jianghai; Wu, Yun; Wang, Xiaobing; Xu, Youxuan; Zhang, Yinong; Wang, Yan

2016-09-24

In this study, methasterone urinary metabolic profiles were investigated by liquid chromatography quadrupole time of flight mass spectrometry (LC-QTOF-MS) in full scan and targeted MS/MS modes with accurate mass measurement. A healthy male volunteer was asked to take the drug and liquid-liquid extraction was employed to process urine samples. Chromatographic peaks for potential metabolites were hunted out with the theoretical [M - H](-) as a target ion in a full scan experiment and actual deprotonated ions were studied in targeted MS/MS experiment. Fifteen metabolites including two new sulfates (S1 and S2), three glucuronide conjugates (G2, G6 and G7), and three free metabolites (M2, M4 and M6) were detected for methasterone. Three metabolites involving G4, G5 and M5 were obtained for the first time in human urine samples. Owing to the absence of helpful fragments to elucidate the steroid ring structure of methasterone phase II metabolites, gas chromatography mass spectrometry (GC-MS) was employed to obtain structural information of the trimethylsilylated phase I metabolite released after enzymatic hydrolysis and the potential structure was inferred using a combined MS method. Metabolite detection times were also analyzed and G2 (18-nor-17β-hydroxymethyl-2α, 17α-dimethyl-androst-13-en-3α-ol-ξ-O-glucuronide) was thought to be new potential biomarker for methasterone misuse which can be detected up to 10 days.

Separation and characterisation of five polar herbicides using countercurrent chromatography with detection by negative ion electrospray ionisation mass spectrometry.

PubMed

Kidwell, H; Jones, J J; Games, D E

2001-01-01

Five polar herbicides were separated and characterised using high-speed analytical countercurrent chromatography (HSACCC) in conjunction with online electrospray mass spectrometry (ESI-MS). The countercurrent chromatography used a standard isocratic biphasic solvent system of hexane/ethyl acetate/methanol/water in reverse phase to effect the separation of these five environmentally important compounds. The chromatograph was coupled to a triple quadrupole mass spectrometer via a standard electrospray liquid chromatography interface that was able to give mass spectra in negative ion mode of each compound. Limits of detection are reported for this series of compounds along with representative negative ion ESI-MS data and calibrations for the separation. Copyright 2001 John Wiley & Sons, Ltd.

Characterization of crude oil biomarkers using comprehensive two-dimensional gas chromatography coupled to tandem mass spectrometry.

PubMed

Mogollón, Noroska Gabriela Salazar; Prata, Paloma Santana; Dos Reis, Jadson Zeni; Neto, Eugênio Vaz Dos Santos; Augusto, Fabio

2016-09-01

Oil samples from Recôncavo basin (NE Brazil), previously analyzed by traditional techniques such as gas chromatography coupled to tandem mass spectrometry, were evaluated using comprehensive two-dimensional gas chromatography coupled to quadrupole mass spectrometry and comprehensive two-dimensional gas chromatography coupled to tandem mass spectrometry along with simplified methods of samples preparation to evaluate the differences and advantages of these analytical techniques to better understand the development of the organic matter in this basin without altering the normal distribution of the compounds in the samples. As a result, the geochemical parameters calculated by comprehensive two-dimensional gas chromatography coupled to tandem mass spectrometry described better the origin, maturity, and biodegradation of both samples probably by increased selectivity, resolution, and sensitivity inherent of the multidimensional technique. Additionally, the detection of the compounds such as, the C(14α-) homo-26-nor-17α-hopane series, diamoretanes, nor-spergulanes, C19 -C26 A-nor-steranes and 4α-methylsteranes resolved and detected by comprehensive two-dimensional gas chromatography coupled to tandem mass spectrometry were key to classify and differentiate these lacustrine samples according to their maturity and deposition conditions. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Parallel Reaction Monitoring: A Targeted Experiment Performed Using High Resolution and High Mass Accuracy Mass Spectrometry

PubMed Central

Rauniyar, Navin

2015-01-01

The parallel reaction monitoring (PRM) assay has emerged as an alternative method of targeted quantification. The PRM assay is performed in a high resolution and high mass accuracy mode on a mass spectrometer. This review presents the features that make PRM a highly specific and selective method for targeted quantification using quadrupole-Orbitrap hybrid instruments. In addition, this review discusses the label-based and label-free methods of quantification that can be performed with the targeted approach. PMID:26633379

High-energy and low-energy collision-induced dissociation of protonated flavonoids generated by MALDI and by electrospray ionization

NASA Astrophysics Data System (ADS)

March, Raymond E.; Li, Hongxia; Belgacem, Omar; Papanastasiou, Dimitris

2007-04-01

Product ion mass spectra of a series of nine protonated flavonoids have been observed by electrospray ionization combined with quadrupole/time-of-flight (ESI QTOF), and matrix-assisted laser desorption ionization combined either with quadrupole ion trap (MALDI QIT) tandem mass spectrometry or time-of-flight tandem mass spectrometry (MALDI TOF ReTOF). The compounds examined are 3,6-, 3,2'-, and 3,3'-dihydoxyflavone, apigenin (5,7,4'-trihydroxyflavone), luteolin (5,7,3',4'-tetrahydroxyflavone), apigenin-7-O-glucoside, hesperidin (5,7,3'-trihydroxy-4'-methoxyflavanone), daidzen (7,4'-dihydroxyisoflavone), and rutin (quercitin-3-O-rutinoside) where quercitin is 3,5,7,3',4'-pentahydroxyflavone; sodiated rutin was examined also. The center-of-mass energies in ESI QTOF and MALDI QIT are similar (1-4 eV) and their product ion mass spectra are virtually identical. In the MALDI TOF ReTOF instrument, center-of-mass energies range from 126-309 eV for sodiated rutin to protonated dihydroxyflavones, respectively. Due to the high center-of-mass energies available with the MALDI TOF ReTOF instrument, some useful structural information may be obtained; however, with increasing precursor mass/charge ratio, product ion mass spectra become simplified so as to be of limited structural value. Electronic excitation of the protonated (and sodiated) species examined here offers an explanation for the very simple product ion mass spectra observed particularly for glycosylated flavonoids.

Chemical fingerprint of Ganmaoling granule by double-wavelength ultra high performance liquid chromatography and ultra high performance liquid chromatography with quadrupole time-of-flight mass spectrometry.

PubMed

Lou, Qiong; Ye, Xiaolan; Zhou, Yingyi; Li, Hua; Song, Fenyun

2015-06-01

A method incorporating double-wavelength ultra high performance liquid chromatography with quadrupole time-of-flight mass spectrometry was developed for the investigation of the chemical fingerprint of Ganmaoling granule. The chromatographic separations were performed on an ACQUITY UPLC HSS C18 column (2.1 × 50 mm, 1.8 μm) at 30°C using gradient elution with water/formic acid (1%) and acetonitrile at a flow rate of 0.4 mL/min. A total of 11 chemical constituents of Ganmaoling granule were identified from their molecular weight, UV spectra, tandem mass spectrometry data, and retention behavior by comparing the results with those of the reference standards or literature. And 25 peaks were selected as the common peaks for fingerprint analysis to evaluate the similarities among 25 batches of Ganmaoling granule. The results of principal component analysis and orthogonal projection to latent structures discriminant analysis showed that the important chemical markers that could distinguish the different batches were revealed as 4,5-di-O-caffeoylquinic acid, 3,5-di-O-caffeoylquinic acid, and 4-O-caffeoylquinic acid. This is the first report of the ultra high performance liquid chromatography chemical fingerprint and component identification of Ganmaoling granule, which could lay a foundation for further studies of Ganmaoling granule. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

TEMPO-Assisted Free Radical-Initiated Peptide Sequencing Mass Spectrometry (FRIPS MS) in Q-TOF and Orbitrap Mass Spectrometers: Single-Step Peptide Backbone Dissociations in Positive Ion Mode

NASA Astrophysics Data System (ADS)

Jang, Inae; Lee, Sun Young; Hwangbo, Song; Kang, Dukjin; Lee, Hookeun; Kim, Hugh I.; Moon, Bongjin; Oh, Han Bin

2017-01-01

The present study demonstrates that one-step peptide backbone fragmentations can be achieved using the TEMPO [2-(2,2,6,6-tetramethyl piperidine-1-oxyl)]-assisted free radical-initiated peptide sequencing (FRIPS) mass spectrometry in a hybrid quadrupole time-of-flight (Q-TOF) mass spectrometer and a Q-Exactive Orbitrap instrument in positive ion mode, in contrast to two-step peptide fragmentation in an ion-trap mass spectrometer (reference Anal. Chem. 85, 7044-7051 (30)). In the hybrid Q-TOF and Q-Exactive instruments, higher collisional energies can be applied to the target peptides, compared with the low collisional energies applied by the ion-trap instrument. The higher energy deposition and the additional multiple collisions in the collision cell in both instruments appear to result in one-step peptide backbone dissociations in positive ion mode. This new finding clearly demonstrates that the TEMPO-assisted FRIPS approach is a very useful tool in peptide mass spectrometry research.

78 FR 11126 - Receipt of Several Pesticide Petitions Filed for Residues of Pesticide Chemicals in or on Various...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-15

... using capillary gas liquid chromatography (GLC) with flame ionization detector (FID). Contact: Andrew...) purification. Detection and quantitation are conducted by gas chromatograph equipped with nitrogen phosphorus... pressure liquid chromatography/triple stage quadrupole mass spectrometry (LC/MS/MS) using the stable...

Comprehensive characterization of ethoxyquin transformation products in fish feed by traveling-wave ion mobility spectrometry coupled to quadrupole time-of-flight mass spectrometry.

PubMed

Negreira, Noelia; Regueiro, Jorge; Valdersnes, Stig; Berntssen, Marc H G; Ørnsrud, Robin

2017-05-01

Feed additives are typically used in intensive farming production over long periods, and hence, they can accumulate in farmed animal tissues. Concerns regarding the use of ethoxyquin as an antioxidant feed additive, have recently arisen due to its potential conversion into a series of transformation products (TPs). The aim of this work was to characterize the TPs of ethoxyquin in fish feed by a novel approach based on the use of traveling-wave ion mobility spectrometry (TWIMS) coupled to high-resolution quadrupole time-of-flight mass spectrometry (QTOFMS). First, ethoxyquin was oxidized under controlled conditions and the generated TPs were added to a comprehensive database. Atlantic salmon feeds were then screened for ethoxyquin TPs using both targeted and untargeted approaches. Twenty-seven TPs were tentatively identified during the oxidation experiments, fifteen of them also being present in the feed samples. In addition, ten other potential TPs were detected in fish feed following the untargeted approach. Thirty-one of these TPs have been reported for the first time in this work through the oxidation experiments and the feed samples. Therefore, this study provides valuable information on the oxidative fate of ethoxyquin in feed, which can be used for future evaluations of potential risk related to this additive. Copyright © 2017 Elsevier B.V. All rights reserved.

Rapid screening and determination of 11 new psychoactive substances by direct analysis in real time mass spectrometry and liquid chromatography/quadrupole time-of-flight mass spectrometry.

PubMed

Nie, Honggang; Li, Xianjiang; Hua, Zhendong; Pan, Wei; Bai, Yanping; Fu, Xiaofang

2016-08-01

With the amounts and types of new psychoactive substances (NPSs) increasing rapidly in recent years, an excellent high-throughput method for the analysis of these compounds is urgently needed. In this article, a rapid screening method and a quantitative analysis method for 11 NPSs are described and compared, respectively. A simple direct analysis in real time mass spectrometry (DART-MS) method was developed for the analysis of 11 NPSs including three categories of these substances present on the global market such as four cathinones, one phenylethylamine, and six synthetic cannabinoids. In order to analyze these compounds quantitatively with better accuracy and sensitivity, another rapid analytical method with a low limit of detection (LOD) was also developed using liquid chromatography/electrospray ionization quadrupole time-of-flight mass spectrometry (LC/QTOFMS). The 11 NPSs could be determined within 0.5 min by DART-MS. Furthermore, they could also be separated and determined within 5 min by the LC/QTOFMS method. The two methods both showed good linearity with correlation coefficients (r(2) ) higher than 0.99. The LODs for all these target NPSs by DART-MS and LC/QTOFMS ranged from 5 to 40 ng mL(-1) and 0.1 to 1 ng mL(-1) , respectively. Confiscated samples, named as "music vanilla" and "bath salt", and 11 spiked samples were firstly screened by DART-MS and then determined by LC/QTOFMS. The identification of NPSs in confiscated materials was successfully achieved, and the proposed analytical methodology could offer rapid screening and accurate analysis results. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Evaluation of the capabilities of atmospheric pressure chemical ionization source coupled to tandem mass spectrometry for the determination of dioxin-like polychlorobiphenyls in complex-matrix food samples.

PubMed

Portolés, T; Sales, C; Abalos, M; Sauló, J; Abad, E

2016-09-21

The use of the novel atmospheric pressure chemical ionization (APCI) source for gas chromatography (GC) coupled to triple quadrupole using tandem mass spectrometry (MS/MS) and its potential for the simultaneous determination of the 12 dioxin-like polychlorobiphenyls (DL-PCBs) in complex food and feed matrices has been evaluated. In first place, ionization and fragmentation behavior of DL-PCBs on the APCI source under charge transfer conditions has been studied followed by their fragmentation in the collision cell. Linearity, repeatability and sensitivity have been studied obtaining instrumental limits of detection and quantification of 0.0025 and 0.005 pg μL(-1) (2.5 and 5 fg on column) respectively for every DL-PCB. Finally, application to real samples has been carried out and DL-PCB congeners (PCB 77, 81, 105, 114, 118, 123, 126, 156, 157, 167, 169, 189) have been detected in the different samples in the range of 0.40-10000 pg g(-1). GC-(APCI)MS/MS has been proved as a suitable alternative to the traditionally accepted confirmation method based on the use of high resolution mass spectrometry and other triple quadrupole tandem mass spectrometry techniques operating with electron ionization. The development of MS/MS methodologies for the analysis of dioxins and DL-PCBs is nowadays particularly important, since this technique was included as a confirmatory method in the present European Union regulations that establish the requirements for the determination of these compounds in food and feed matrices. Copyright © 2016 Elsevier B.V. All rights reserved.

A peptidomic approach for monitoring and characterising peptide cyanotoxins produced in Italian lakes by matrix-assisted laser desorption/ionisation and quadrupole time-of-flight mass spectrometry.

PubMed

Ferranti, Pasquale; Nasi, Antonella; Bruno, Milena; Basile, Adriana; Serpe, Luigi; Gallo, Pasquale

2011-05-15

In recent years, the occurrence of cyanobacterial blooms in eutrophic freshwaters has been described all over the world, including most European countries. Blooms of cyanobacteria may produce mixtures of toxic secondary metabolites, called cyanotoxins. Among these, the most studied are microcystins, a group of cyclic heptapeptides, because of their potent hepatotoxicity and activity as tumour promoters. Other peptide cyanotoxins have been described whose structure and toxicity have not been thoroughly studied. Herein we present a peptidomic approach aimed to characterise and quantify the peptide cyanotoxins produced in two Italian lakes, Averno and Albano. The procedure was based on matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry mass spectrometry (MALDI-TOF-MS) analysis for rapid detection and profiling of the peptide mixture complexity, combined with liquid chromatography/electrospray ionisation quadrupole time-of- flight tandem mass spectrometry (LC/ESI-Q-TOF-MS/MS) which provided unambiguous structural identification of the main compounds, as well as accurate quantitative analysis of microcystins. In the case of Lake Averno, a novel variant of microcystin-RR and two novel anabaenopeptin variants (Anabaenopeptins B(1) and Anabaenopeptin F(1)), presenting homoarginine in place of the commonly found arginine, were detected and characterised. In Lake Albano, the peculiar peptide patterns in different years were compared, as an example of the potentiality of the peptidomic approach for fast screening analysis, prior to fine structural analysis and determination of cyanotoxins, which included six novel aeruginosin variants. This approach allows for wide range monitoring of cyanobacteria blooms, and to collect data for evaluating possible health risks to consumers, through the panel of the compounds produced along different years. Copyright © 2011 John Wiley & Sons, Ltd.

Identification of multiple constituents in Chinese medicinal prescription Shensong Yangxin capsule by ultra-fast liquid chromatography combined with quadrupole time-of-flight mass spectrometry.

PubMed

Liu, Minyan; Zhao, Shaohua; Wang, Yufeng; Liu, Ting; Li, Song; Wang, Hongtao; Tu, Pengfei

2015-02-01

A practical method using ultra-fast liquid chromatography in tandem with quadrupole time-of-flight mass spectrometry combined with dynamic background subtraction technology was developed for the rapid separation and identification of the complicated constituents in the Shensong Yangxin capsule (SSYX). The chromatographic separation was performed on a C18 column (2.1 × 100 mm, 2.6 μm) with a gradient elution program using methanol and 0.1% formic acid aqueous solution as the mobile phase at a flow rate of 0.4 mL min(-1). Accurate mass measurements of the molecular ions in the full scan and the characteristic fragment ions triggered by information-dependent acquisition provided reliable identification criteria. Thus, 99 compounds, including saponins, phenolic acids, tanshinones, lignans, terpenoids, alkaloids and flavonoids, were unambiguously or tentatively identified in 40 min by comparing their retention times and accurate mass measurements for each molecular ion and its subsequent fragment ions with those of authentic standards or literature data. Simultaneously, all the compounds were further assigned to the individual raw materials. In conclusion, these results will provide a basis for quality control and further study of SSYX, and the proposed technique based on high-resolution mass spectrometry would be expected to be adaptable to the analysis of complicated constituents in various complex matrices. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Inductively coupled plasma mass spectrometry for stable isotope metabolic tracer studies of living systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Luong, Elise

1999-05-10

This dissertation focuses on the development of methods for stable isotope metabolic tracer studies in living systems using inductively coupled plasma single and dual quadrupole mass spectrometers. Sub-nanogram per gram levels of molybdenum (Mo) from human blood plasma are isolated by the use of anion exchange alumina microcolumns. Million-fold more concentrated spectral and matrix interferences such as sodium, chloride, sulfate, phosphate, etc. in the blood constituents are removed from the analyte. The recovery of Mo from the alumina column is 82 ± 5% (n = 5). Isotope dilution inductively coupled plasma mass spectrometry (ID-ICP-MS) is utilized for the quantitative ultra-tracemore » concentration determination of Mo in bovine and human blood samples. The average Mo concentration in reference bovine serum determined by this method is 10.2 ± 0.4 ng/g, while the certified value is 11.5 ± 1.1 ng/g (95% confidence interval). The Mo concentration of one pool of human blood plasma from two healthy male donors is 0.5 ± 0.1 ng/g. The inductively coupled plasma twin quadrupole mass spectrometer (ICP-TQMS) is used to measure the carbon isotope ratio from non-volatile organic compounds and bio-organic molecules to assess the ability as an alternative analytical method to gas chromatography combustion isotope ratio mass spectrometry (GC-combustion-IRMS). Trytophan, myoglobin, and β-cyclodextrin are chosen for the study, initial observation of spectral interference of 13C + with 12C 1H + comes from the incomplete dissociation of myoglobin and/or β-cyclodextrin.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Adamson, B. D.; Coughlan, N. J. A.; Markworth, P. B.

An ion mobility mass spectrometry apparatus for investigating the photoisomerization and photodissociation of electrosprayed molecular ions in the gas phase is described. The device consists of a drift tube mobility spectrometer, with access for a laser beam that intercepts the drifting ion packet either coaxially or transversely, followed by a quadrupole mass filter. An ion gate halfway along the drift region allows the instrument to be used as a tandem ion mobility spectrometer, enabling mobility selection of ions prior to irradiation, with the photoisomer ions being separated over the second half of the drift tube. The utility of the devicemore » is illustrated with photoisomerization and photodissociation action spectra of carbocyanine molecular cations. The mobility resolution of the device for singly charged ions is typically 80 and it has a mass range of 100-440 Da, with the lower limit determined by the drive frequency for the ion funnels, and the upper limit by the quadrupole mass filter.« less

Liquid chromatography/quadrupole-time-of-flight mass spectrometry with metabolic profiling of human urine as a tool for environmental analysis of dextromethorphan.

PubMed

Thurman, E Michael; Ferrer, Imma

2012-10-12

We use the combination of liquid chromatography/quadrupole-time-of-flight mass spectrometry (LC/Q-TOF-MS) and urine metabolic profiling to find and identify the metabolites of dextromethorphan, a common over-the-counter (OTC) cough suppressant. Next, we use the combination of ion masses, their MS/MS fragmentation, and retention times to determine dextromethorphan and its metabolites in surface water impacted by wastewater. Prior to this study, neither dextromethorphan nor its metabolites have been reported in surface water; in spite of its common use in over 100 various OTC medications. We found that the concentration of the dextrorphan metabolite in surface water greatly exceeded the parent compound by factors of 5-10 times, which reflects the urine profile, where parent compound is approximately <2% of the total excreted drug based on ion intensities. Urine profiling also indicated that glucuronide metabolites are major phase 2 products (92% of the total) in urine and then are completely hydrolyzed in wastewater to dextrorphan and N-demethyldextrorphan, which are phase 1 metabolites-a "kind of reversal" of human metabolism. Copyright © 2012 Elsevier B.V. All rights reserved.

Liquid chromatographic/electrospray ionization quadrupole/time of flight tandem mass spectrometric study of polyphenolic composition of different Vaccinium berry species and their comparative evaluation.

PubMed

Ancillotti, Claudia; Ciofi, Lorenzo; Rossini, Daniele; Chiuminatto, Ugo; Stahl-Zeng, Jianru; Orlandini, Serena; Furlanetto, Sandra; Del Bubba, Massimo

2017-02-01

Ultra-high-performance liquid chromatography coupled with high-resolution quadrupole-time of flight mass spectrometry with both negative and positive ionization was used for comprehensively investigating the phenolic and polyphenolic compounds in berries from three spontaneous or cultivated Vaccinium species (i.e., Vaccinium myrtillus, Vaccinium uliginosum subsp. gaultherioides, and Vaccinium corymbosum). More than 200 analytes, among phenolic and polyphenolic compounds belonging to the classes of anthocyanins, monomeric and oligomeric flavonols, flavanols, dihydrochalcones, phenolic acids, together with other polyphenolic compounds of mixed structural characteristics, were identified. Some of the polyphenols herein investigated, such as anthocyanidin glucuronides and malvidin-feruloyl-hexosides in V. myrtillus, or anthocyanindin aldopentosides and coumaroyl-hexosides in V. uliginosum subsp. gaultherioides and a large number of proanthocyanidins with high molecular weight in all species, were described for the first time in these berries. Principal component analysis applied on original LC-TOF data, acquired in survey scan mode, successfully discriminated the three Vaccinium berry species investigated, on the basis of their polyphenolic composition, underlying one more time the fundamental role of mass spectrometry for food characterization.

Structural Characterization of New Peptide Variants Produced by Cyanobacteria from the Brazilian Atlantic Coastal Forest Using Liquid Chromatography Coupled to Quadrupole Time-of-Flight Tandem Mass Spectrometry

PubMed Central

Sanz, Miriam; Andreote, Ana Paula Dini; Fiore, Marli Fatima; Dörr, Felipe Augusto; Pinto, Ernani

2015-01-01

Cyanobacteria from underexplored and extreme habitats are attracting increasing attention in the search for new bioactive substances. However, cyanobacterial communities from tropical and subtropical regions are still largely unknown, especially with respect to metabolite production. Among the structurally diverse secondary metabolites produced by these organisms, peptides are by far the most frequently described structures. In this work, liquid chromatography/electrospray ionization coupled to high resolution quadrupole time-of-flight tandem mass spectrometry with positive ion detection was applied to study the peptide profile of a group of cyanobacteria isolated from the Southeastern Brazilian coastal forest. A total of 38 peptides belonging to three different families (anabaenopeptins, aeruginosins, and cyanopeptolins) were detected in the extracts. Of the 38 peptides, 37 were detected here for the first time. New structural features were proposed based on mass accuracy data and isotopic patterns derived from full scan and MS/MS spectra. Interestingly, of the 40 surveyed strains only nine were confirmed to be peptide producers; all of these strains belonged to the order Nostocales (three Nostoc sp., two Desmonostoc sp. and four Brasilonema sp.). PMID:26096276

Alkaloids Profiling of Fumaria capreolata by Analytical Platforms Based on the Hyphenation of Gas Chromatography and Liquid Chromatography with Quadrupole-Time-of-Flight Mass Spectrometry.

PubMed

Contreras, María Del Mar; Bribi, Noureddine; Gómez-Caravaca, Ana María; Gálvez, Julio; Segura-Carretero, Antonio

2017-01-01

Two analytical platforms, gas chromatography (GC) coupled to quadrupole-time-of-flight (QTOF) mass spectrometry (MS) and reversed-phase ultrahigh performance liquid chromatography (UHPLC) coupled to diode array (DAD) and QTOF detection, were applied in order to study the alkaloid profile of Fumaria capreolata . The use of these mass analyzers enabled tentatively identifying the alkaloids by matching their accurate mass signals and suggested molecular formulae with those previously reported in libraries and databases. Moreover, the proposed structures were corroborated by studying their fragmentation pattern obtained by both platforms. In this way, 8 and 26 isoquinoline alkaloids were characterized using GC-QTOF-MS and RP-UHPLC-DAD-QTOF-MS, respectively, and they belonged to the following subclasses: protoberberine, protopine, aporphine, benzophenanthridine, spirobenzylisoquinoline, morphinandienone, and benzylisoquinoline. Moreover, the latter analytical method was selected to determine at 280 nm the concentration of protopine (9.6 ± 0.7 mg/g), a potential active compound of the extract. In conclusion, although GC-MS has been commonly used for the analysis of this type of phytochemicals, RP-UHPLC-DAD-QTOF-MS provided essential complementary information. This analytical method can be applied for the quality control of phytopharmaceuticals containing Fumaria extracts currently found in the market.

Alkaloids Profiling of Fumaria capreolata by Analytical Platforms Based on the Hyphenation of Gas Chromatography and Liquid Chromatography with Quadrupole-Time-of-Flight Mass Spectrometry

PubMed Central

Bribi, Noureddine; Gómez-Caravaca, Ana María

2017-01-01

Two analytical platforms, gas chromatography (GC) coupled to quadrupole-time-of-flight (QTOF) mass spectrometry (MS) and reversed-phase ultrahigh performance liquid chromatography (UHPLC) coupled to diode array (DAD) and QTOF detection, were applied in order to study the alkaloid profile of Fumaria capreolata. The use of these mass analyzers enabled tentatively identifying the alkaloids by matching their accurate mass signals and suggested molecular formulae with those previously reported in libraries and databases. Moreover, the proposed structures were corroborated by studying their fragmentation pattern obtained by both platforms. In this way, 8 and 26 isoquinoline alkaloids were characterized using GC-QTOF-MS and RP-UHPLC-DAD-QTOF-MS, respectively, and they belonged to the following subclasses: protoberberine, protopine, aporphine, benzophenanthridine, spirobenzylisoquinoline, morphinandienone, and benzylisoquinoline. Moreover, the latter analytical method was selected to determine at 280 nm the concentration of protopine (9.6 ± 0.7 mg/g), a potential active compound of the extract. In conclusion, although GC-MS has been commonly used for the analysis of this type of phytochemicals, RP-UHPLC-DAD-QTOF-MS provided essential complementary information. This analytical method can be applied for the quality control of phytopharmaceuticals containing Fumaria extracts currently found in the market. PMID:29348751

Reaction of β-blockers and β-agonist pharmaceuticals with aqueous chlorine. Investigation of kinetics and by-products by liquid chromatography quadrupole time-of-flight mass spectrometry.

PubMed

Quintana, José Benito; Rodil, Rosario; Cela, Rafael

2012-06-01

The degradation of two β-blockers (atenolol and propranolol) and one β-receptor agonist (salbutamol) during water chlorination was investigated by liquid chromatography-mass spectrometry (LC-MS). An accurate-mass quadrupole time-of-flight system (QTOF) was used to follow the time course of the pharmaceuticals and also used in the identification of the by-products. The degradation kinetics of these drugs was investigated at different concentrations of chlorine, bromide and sample pH by means of a Box-Behnken experimental design. Depending on these factors, dissipation half-lives varied in the ranges 68-145 h for atenolol, 1.3-33 min for salbutamol and 42-8362 min for propranolol. Normally, an increase in chlorine dosage and pH resulted in faster degradation of these pharmaceuticals. Moreover, the presence of bromide in water samples also resulted in a faster transformation of atenolol at low chlorine doses. The use of an accurate-mass high-resolution LC-QTOF-MS system permitted the identification of a total of 14 by-products. The transformation pathway of β-blockers/agonists consisted mainly of halogenations, hydroxylations and dealkylations. Also, many of these by-products are stable, depending on the chlorination operational parameters employed.

Evaluating Mass Analyzers as Candidates for Small, Portable, Rugged Single Point Mass Spectrometers for Analysis of Permanent Gases

NASA Technical Reports Server (NTRS)

Arkin, C. Richard; Ottens, Andrew K.; Diaz, Jorge A.; Griffin, Timothy P.; Follestein, Duke; Adams, Fredrick; Steinrock, T. (Technical Monitor)

2001-01-01

For Space Shuttle launch safety, there is a need to monitor the concentration of H2, He, O2 and Ar around the launch vehicle. Currently a large mass spectrometry system performs this task, using long transport lines to draw in samples. There is great interest in replacing this stationary system with several miniature, portable, rugged mass spectrometers which act as point sensors which can be placed at the sampling point. Five commercial and two non-commercial analyzers are evaluated. The five commercial systems include the Leybold Inficon XPR-2 linear quadrupole, the Stanford Research (SRS-100) linear quadrupole, the Ferran linear quadrupole array, the ThermoQuest Polaris-Q quadrupole ion trap, and the IonWerks Time-of-Flight (TOF). The non-commercial systems include a compact double focusing sector (CDFMS) developed at the University of Minnesota, and a quadrupole ion trap (UF-IT) developed at the University of Florida. The System Volume is determined by measuring the entire system volume including the mass analyzer, its associated electronics, the associated vacuum system, the high vacuum pump and rough pump. Also measured are any ion gauge controllers or other required equipment. Computers are not included. Scan Time is the time required for one scan to be acquired and the data to be transferred. It is determined by measuring the time required acquiring a known number of scans and dividing by said number of scans. Limit of Detection is determined first by performing a zero-span calibration (using a 10-point data set). Then the limit of detection (LOD) is defined as 3 times the standard deviation of the zero data set. (An LOD of 10 ppm or less is considered acceptable.)

The Mechanism of Boron Mobility in Wheat and Canola Phloem1[C][OA

PubMed Central

Stangoulis, James; Tate, Max; Graham, Robin; Bucknall, Martin; Palmer, Lachlan; Boughton, Berin; Reid, Robert

2010-01-01

Low-molecular-weight borate complexes were isolated from canola (Brassica napus) and wheat (Triticum aestivum) phloem exudates, as well as the cytoplasm of the fresh-water alga Chara corallina, and identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Phloem exudate was collected from field-grown canola inflorescence stalks by shallow incision, while wheat phloem exudate was collected by aphid stylectomy. Chara cytoplasm was collected by careful manual separation of the cell wall, vacuole, and cytosolic compartments. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry showed the presence of isotopic borate complexes, at mass-to-charge ratio of 690.22/691.22 in the canola and wheat phloem and at 300.11/301.11 in canola phloem and Chara cytoplasm. Using reference compounds, the borate complexes with mass-to-charge ratio 690.22/691.22 was identified as a bis-sucrose (Suc) borate complex in which the 4,6-hydroxyl pairs from the two α-glucopyranoside moieties formed an [L2B]−1 complex. Further investigation using liquid chromatography electrospray ionization triple quadrupole mass spectrometry analysis confirmed the presence of the bis-Suc borate complex in wheat phloem with a concentration up to 220 μm. The 300.11/301.11 complex was putatively identified as a bis-N-acetyl-serine borate complex but its concentration was below the detection limits of the liquid chromatography electrospray ionization triple quadrupole mass spectrometer so could not be quantified. The presence of borate complexes in the phloem provides a mechanistic explanation for the observed phloem boron mobility in canola and wheat and other species that transport Suc as their primary photoassimilate. PMID:20413647

Analysis of hydraulic fracturing additives by LC/Q-TOF-MS.

PubMed

Ferrer, Imma; Thurman, E Michael

2015-08-01

The chemical additives used in fracturing fluids can be used as tracers of water contamination caused by hydraulic fracturing operations. For this purpose, a complete chemical characterization is necessary using advanced analytical techniques. Liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (LC/Q-TOF-MS) was used to identify chemical additives present in flowback and produced waters. Accurate mass measurements of main ions and fragments were used to characterize the major components of fracking fluids. Sodium adducts turned out to be the main molecular adduct ions detected for some additives due to oxygen-rich structures. Among the classes of chemical components analyzed by mass spectrometry include gels (guar gum), biocides (glutaraldehyde and alkyl dimethyl benzyl ammonium chloride), and surfactants (cocamidopropyl dimethylamines, cocamidopropyl hydroxysultaines, and cocamidopropyl derivatives). The capabilities of accurate mass and MS-MS fragmentation are explored for the unequivocal identification of these compounds. A special emphasis is given to the mass spectrometry elucidation approaches used to identify a major class of hydraulic fracturing compounds, surfactants.

DC Potentials Applied to an End-cap Electrode of a 3-D Ion Trap for Enhanced MSn Functionality

PubMed Central

Prentice, Boone M.; Xu, Wei; Ouyang, Zheng; McLuckey, Scott A.

2010-01-01

The effects of the application of various DC magnitudes and polarities to an end-cap of a 3-D quadrupole ion trap throughout a mass spectrometry experiment were investigated. Application of a monopolar DC field was achieved by applying a DC potential to the exit end-cap electrode, while maintaining the entrance end-cap electrode at ground potential. Control over the monopolar DC magnitude and polarity during time periods associated with ion accumulation, mass analysis, ion isolation, ion/ion reaction, and ion activation can have various desirable effects. Included amongst these are increased ion capture efficiency, increased ion ejection efficiency during mass analysis, effective isolation of ions using lower AC resonance ejection amplitudes, improved temporal control of the overlap of oppositely charged ion populations, and the performance of “broad-band” collision induced dissociation (CID). These results suggest general means to improve the performance of the 3-D ion trap in a variety of mass spectrometry and tandem mass spectrometry experiments. PMID:21927573

Mycotoxins, pesticides and toxic metals in commercial spices and herbs.

PubMed

Reinholds, Ingars; Pugajeva, Iveta; Bavrins, Konstantins; Kuckovska, Galina; Bartkevics, Vadims

2017-03-01

A total of 300 samples representing six condiments (black pepper, basil, oregano, nutmeg, paprika, and thyme) were analysed for 11 mycotoxins, 134 pesticides and 4 heavy metals by ultra-high performance liquid chromatography-tandem quadrupole mass spectrometry and inductively coupled plasma mass spectrometry. Mycotoxins were detected in 4%, 10% and 30% of all nutmeg, basil and thyme samples, respectively. The residues of 24 pesticides were detected in 59% of the analysed condiments. The maximum residue levels of pesticides were exceeded in 10% of oregano and 46% of thyme samples. A risk assessment of heavy metals was performed, indicating daily intake levels far below the tolerable intake levels.

Application of Ultra-performance Liquid Chromatography with Time-of-Flight Mass Spectrometry for the Rapid Analysis of Constituents and Metabolites from the Extracts of Acanthopanax senticosus Harms Leaf

PubMed Central

Zhang, Yingzhi; Zhang, Aihua; Zhang, Ying; Sun, Hui; Meng, Xiangcai; Yan, Guangli; Wang, Xijun

2016-01-01

Acanthopanax senticosus (Rupr and Maxim) Harms (AS), a member of Araliaceae family, is a typical folk medicinal herb, which is widely distributed in the Northeastern part of China. Due to lack of this resource caused by the extensive use of its root, this work studied the chemical constituents of leaves of this plant with the purpose of looking for an alternative resource. In this work, a fast and optimized ultra-performance liquid chromatography method with quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) has been developed for the analysis of constituents in leaves extracts. A total of 131 compounds were identified or tentatively characterized including triterpenoid saponins, phenols, flavonoids, lignans, coumarins, polysaccharides, and other compounds based on their fragmentation behaviors. Besides, a total of 21 metabolites were identified in serum in rats after oral administration, among which 12 prototypes and 9 metabolites through the metabolic pathways of reduction, methylation, sulfate conjugation, sulfoxide to thioether and deglycosylation. The coupling of UPLC-QTOF-MS led to the in-depth characterization of the leaves extracts of AS both in vitro and in vivo on the basis of retention time, mass accuracy, and tandem MS/MS spectra. It concluded that this analytical tool was very valuable in the study of complex compounds in medicinal herb. HIGHLIGHT OF PAPER A fast UPLC-QTOF-MS has been developed for analysis of constituents in leaves extractsA total of 131 compounds were identified in leaves extractsA total of 21 metabolites including 12 prototypes and 9 metabolites were identified in vivo. SUMMARY Constituent’s analysis of Acanthopanax senticosus Harms leaf by ultra-performance liquid chromatography method with quadrupole time-of-flight mass spectrometry. Abbreviations used: AS: Acanthopanax senticosus (Rupr and Maxim) Harms, TCHM: Traditional Chinese herbal medicine, UPLC-QTOF-MS: Ultra-performance liquid chromatography method with time-of-flight mass spectrometry, MS/MS: Tandem mass spectrometry, PCA: Principal component analysis, PLS-DA: Partial least squared discriminant analysis, OPLS-DA: Orthogonal projection to latent structure-discriminant analysis. PMID:27076752

Quantitative LC–MS for water-soluble heterocyclic amines in fine aerosols (PM2.5) at Duke Forest, USA

EPA Science Inventory

In this study, a quantitative liquid chromatography-mass spectrometry (LC-MS) technique capable of measuring the concentrations of heterocyclic nitrogen compounds in ambient fine aerosols (PM2.5) has been developed. Quadrupole time-of-flight (Q-TOF) MS technology is used to provi...

Identification in Rat Plasma and Urine by Linear Trap Quadrupole-Orbitrap Mass Spectrometry of the Metabolites of Maslinic Acid, a Triterpene from Olives.

PubMed

Sánchez-González, Marta; Lozano-Mena, Glòria; Parra, Andrés; Juan, M Emília; Planas, Joana M

2015-02-04

Maslinic acid is a natural pentacyclic triterpenoid widely distributed in edible and medicinal plants with health-promoting activities. The identification and quantification of its metabolites is a requirement for a better understanding of the biological effects of this triterpene. Therefore, maslinic acid was orally administered to Sprague-Dawley rats at a dose of 50 mg/kg of body weight. Blood and urine were withdrawn at 45 min. Samples were extracted with ethyl acetate prior to liquid chromatography-atmospheric pressure chemical ionization-linear trap quadrupole-Orbitrap (LC-APCI-LTQ-Orbitrap) analysis. Screening of plasma yielded four monohydroxylated derivatives (M1-M4), one monohydroxylated and dehydrogenated metabolite (M5), and two dihydroxylated and dehydrogenated compounds (M6 and M7). In urine, M1, M4, M5, and M6 were detected. Quantification by LC-APCI-mass spectrometry (MS) revealed maslinic acid as the prevalent compound in both plasma (81.8%) and urine (73.9%), which indicates that metabolism is low and mainly attributable to phase I reactions.

[Simultaneous determination of 22 typical pharmaceuticals and personal care products in environmental water using ultra performance liquid chromatography- triple quadrupole mass spectrometry].

PubMed

Wu, Chunying; Gu, Feng; Bai, Lu; Lu, Wenlong

2015-08-01

An analytical method for simultaneous determination of 22 typical pharmaceuticals and personal care products (PPCPs) in environmental water samples was developed by ultra performance liquid chromatography-triple quadrupole mass spectrometry (UPLC-MS/MS). An Oasis HLB solid phase extraction cartridge, methanol as washing solution, water containing 0. 1% formic acid-methanol (7:3, v/v) as the mobile phases were selected for sample pretreatment and chromatographic separation. Based on the optimized sample pretreatment procedures and separation condition, the target recoveries ranged from 73% to 125% in water with the relative standard deviations ( RSDs) from 8.8% to 17.5%, and the linear ranges were from 2 to 2 000 µg/L with correlation coefficients (R2) not less than 0.997. The method can be applied to simultaneous determination of the 22 typical PPCPs in environmental water samples because of its low detection limits and high recoveries. It can provide support and help for the related research on water environmental risk assessment and control of the micro-organic pollutants.

Pesticide residues determination in Polish organic crops in 2007-2010 applying gas chromatography-tandem quadrupole mass spectrometry.

PubMed

Walorczyk, Stanisław; Drożdżyński, Dariusz; Kowalska, Jolanta; Remlein-Starosta, Dorota; Ziółkowski, Andrzej; Przewoźniak, Monika; Gnusowski, Bogusław

2013-08-15

A sensitive, accurate and reliable multiresidue method based on the application of gas chromatography-tandem quadrupole mass spectrometry (GC-QqQ-MS/MS) has been established for screening, identification and quantification of a large number of pesticide residues in produce. The method was accredited in compliance with PN-EN ISO/IEC 17025:2005 standard and it was operated under flexible scope as PB-11 method. The flexible scope of accreditation allowed for minor modifications and extension of the analytical scope while using the same analytical technique. During the years 2007-2010, the method was used for the purpose of verification of organic crop production by multiresidue analysis for the presence of pesticides. A total of 528 samples of differing matrices such as fruits, vegetables, cereals, plant leaves and other green parts were analysed, of which 4.4% samples contained pesticide residues above the threshold value of 0.01 mg/kg. A total of 20 different pesticide residues were determined in the samples. Copyright © 2013 Elsevier Ltd. All rights reserved.

HPLC/ESI-quadrupole ion trap mass spectrometry for characterization and direct quantification of amphoteric and nonionic surfactants in aqueous samples

NASA Technical Reports Server (NTRS)

Levine, Lanfang H.; Garland, Jay L.; Johnson, Jodie V.

2002-01-01

An amphoteric (cocamidopropylbetaine, CAPB) and a nonionic (alcohol polyethoxylate, AE) surfactant were characterized by electrospray ionization quadrupole ion trap mass spectrometry (ESI-MS) as to their homologue distribution and ionization/fragmentation chemistry. Quantitative methods involving reversed-phase gradient HPLC and (+)ESI-MSn were developed to directly determine these surfactants in hydroponic plant growth medium that received simulated graywater. The predominant homologues, 12 C alkyl CAPB and 9 EO AE, were monitored to represent the total amount of the respective surfactants. The methods demonstrated dynamic linear ranges of 0.5-250 ng (r2 > 0.996) for CAPB and 8-560 ng (r2 > 0.998) for AE homologue mixture, corresponding to minimum quantification limits of 25 ppb CAPB and 0.4 ppm AE with 20-microL injections. This translated into an even lower limit for individual components due to the polydispersive nature of the surfactants. The procedure was successfully employed for the assessment of CAPB and AE biodegradation in a hydroponic plant growth system used as a graywater bioreactor.

A strategy for untargeted screening of macrolides and metabolites in bass by liquid chromatography coupled to quadrupole orbitrap mass spectrometry.

PubMed

Jia, Wei; Shi, Lin; Chu, Xiaogang; Chang, James; Chen, Ying; Zhang, Feng

2018-10-01

An analytical method for the non-target screening of macrolides and metabolites in bass (Lateolabrax) was developed using an automated on-line extraction procedure followed by ultrahigh-performance liquid chromatography coupled to electrospray ionization quadrupole Orbitrap high-resolution mass spectrometry (UHPLC Q-Orbitrap). The estimated performance characteristics were satisfied, complying with the requirements of the guidelines specified in European Commission Decision 2002/657/EC. The decision limit ranged from 0.12 μg kg -1 to 3.61 μg kg -1 , and detection capability ranged between 0.20 μg kg -1 and 6.02 μg kg -1 . Precision in terms of relative standard deviation (RSD) was under 14% for all compounds, and the extraction recoveries ranged from 81% to 107%. Finally, the method was applied to ten different commercially important bass species and confirmed the presence of ten macrolides and metabolites. Five non-target compounds of robenidine, lincomycin hydrochloride, thiacloprid, fenbendazole, and thiabendazole were elucidated in the untargeted screening. Copyright © 2018 Elsevier Ltd. All rights reserved.

Fast analysis of triterpenoids in Ganoderma lucidum spores by ultra-performance liquid chromatography coupled with triple quadrupole mass spectrometry.

PubMed

Yan, Zhou; Xia, Bing; Qiu, Ming Hua; Li Sheng, Ding; Xu, Hong Xi

2013-11-01

A rapid and reliable method was established for simultaneous determination of main triterpenoids in Ganoderma lucidum spores using ultra-high-performance liquid chromatography coupled with triple quadrupole mass spectrometry (UPLC-TQ-MS). The established method was validated in terms of linearity, sensitivity, precision, accuracy and stability, and was successfully applied to determine the contents of 10 main triterpenoids in different batches of G. lucidum spores. The analysis results showed that moderate levels of triterpenoids were found in G. lucidum spores. In addition, a MS full scan with a daughter ion scan experiment was performed to identify the potential derivatives of triterpenoids present in G. lucidum spores. As a result, a total of 22 triterpenoids from different G. lucidum spores were unequivocally or tentatively identified via comparisons with authentic standards and literatures. This method provides both qualitative and quantitative results without the need for repetitive UPLC-MS analyses, thereby increasing efficiency and productivity, making it suitable for high-throughput applications. Copyright © 2013 John Wiley & Sons, Ltd.

Metabolic profiling of nuciferine in rat urine, plasma, bile and feces after oral administration using ultra-high performance liquid chromatography-diode array detection-quadrupole time-of-flight mass spectrometry.

PubMed

Wu, Xiao-Lei; Wu, Ming-Jiang; Chen, Xin-Ze; Ma, Hao-Ling; Ding, Li-Qin; Qiu, Feng; Pan, Qin; Zhang, De-Qin

2017-06-05

Nuciferine, a major alkaloid found in Nelumbinis Folium, exhibits a broad spectrum of bioactivities, such as antiobesity, anti-diabetes and anti-inflammatory. However, many research regarding nuciferine focused on the extraction, isolation and biological activity, the metabolism is not comprehensively explained in vivo. Thence, the present of this paper is to establish a simple method for speculating metabolites of nuciferine. A total of 15 metabolites were detected and tentatively identified through ultra high performance liquid chromatography-diode array detection-quadrupole time-of-flight mass spectrometry (UHPLC-DAD-QTOF-MS), including 7 new metabolites. Among them, we also discovered a previously unmentioned metabolically active site at the C 1 -OCH 3 position. These metabolites suggested that demethylation, oxidation, glucuronidation and sulfation were major metabolic pathways. This study provided significant experiment basis for its safety estimate and valuable information about the metabolism of nuciferine, which will be advantageous for new drug development. Copyright © 2017 Elsevier B.V. All rights reserved.

Characterization of isochlorogenic acid A metabolites in rats using high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry.

PubMed

Wang, Jing; Cao, Guoxiu; Wang, Hong; Ye, Hui; Zhong, Yunxi; Wang, Guangji; Hao, Haiping

2017-08-01

Isochlorogenic acid A is widely present in fruits, vegetables and herbal medicines, and is characterized by anti-inflammatory, hepatoprotective and antiviral properties. However, little is known about its metabolic fate and pharmacokinetic properties. This study is thus designed to investigate the metabolic fate of isochlorogenic acid A. An analytical method based on high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (HPLC/Q-TOF MS) was established to characterize the metabolites of isochlorogenic acid A in the plasma, urine and feces of rats. A total of 32 metabolites were identified. The metabolic pathways mainly include hydrolyzation, dehydroxylation, hydrogenation and conjugation with methyl, glucuronic acid, glycine, sulfate, glutathione and cysteine. Moreover, the pharmacokinetic profiles of all the circulating metabolites were investigated. M11 resulting from hydrolyzation, dehydroxylation and hydrogenation was the dominant circulating metabolite after the intragastric administration of isochlorogenic acid A. The results obtained will be useful for further study of elucidating potential bioactive metabolites which can provide better explanation of the pharmacological and/or toxicological effects of this compound. Copyright © 2017 John Wiley & Sons, Ltd.

Determination of flubendiamide in honey at trace levels by using solid phase extraction and liquid chromatography coupled to quadrupole time-of-flight mass spectrometry.

PubMed

Ares, Ana M; Valverde, Silvia; Bernal, José L; Toribio, Laura; Nozal, María J; Bernal, José

2017-10-01

In this study, a new method has been developed to determine flubendiamide in honey using liquid chromatography coupled to a selective mass spectrometry detector (quadrupole-time-of-flight). An efficient sample treatment involving a solid phase extraction with a C 18 sorbent was proposed (average analyte recoveries were between 94 and 104%). Chromatographic analysis (9min) was performed on a C 18 column (Gemini C 18 , 50×2.0mm, 3µm, 110Å). The mobile phase consisted of water and acetonitrile, with a flow rate of 0.5mL/min in gradient elution mode. The method was fully validated in terms of selectivity, limits of detection and quantification, matrix effect, linearity, trueness and precision. Low limits of detection and quantification were obtained, ranging from 0.1 to 0.2µg/kg and 0.4 to 0.6µg/kg, respectively. The method was applied to analyze flubendiamide in honey from different botanic origins (multifloral, rosemary and heather). Copyright © 2017 Elsevier Ltd. All rights reserved.

Systematic Analysis of Absorbed Anti-Inflammatory Constituents and Metabolites of Sarcandra glabra in Rat Plasma Using Ultra-High-Pressure Liquid Chromatography Coupled with Linear Trap Quadrupole Orbitrap Mass Spectrometry.

PubMed

Li, Xiong; Zhao, Jin; Liu, Jianxing; Li, Geng; Zhao, Ya; Zeng, Xing

2016-01-01

Ultra-high-pressure liquid chromatography (UHPLC) was coupled with linear ion trap quadrupole Orbitrap mass spectrometry (LTQ-Orbitrap) and was used for the first time to systematically analyze the absorbed components and metabolites in rat plasma after oral administration of the water extract of Sarcandra glabra. This extract is a well-known Chinese herbal medicine for the treatment of inflammation and immunity related diseases. The anti-inflammatory activities of the absorbed components were evaluated by measuring nitric oxide (NO) production and proinflammatory genes expression in lipopolysaccharide (LPS)-stimulated murine RAW 264.7 macrophages. As a result, 54 components in Sarcandra glabra were detected in dosed rat plasma, and 36 of them were positively identified. Moreover, 23 metabolites were characterized and their originations were traced. Furthermore, 20 of the 24 studied components showed anti-inflammatory activities. These results provide evidence that this method efficiency detected constituents in plasma based on the anti-inflammatory mechanism of multiple components and would be a useful technique for screening multiple targets for natural medicine research.

Metabolic Profile of Zearalenone in Liver Microsomes from Different Species and Its in Vivo Metabolism in Rats and Chickens Using Ultra High-Pressure Liquid Chromatography-Quadrupole/Time-of-Flight Mass Spectrometry.

PubMed

Yang, Shupeng; Zhang, Huiyan; Sun, Feifei; De Ruyck, Karl; Zhang, Jinzhen; Jin, Yue; Li, Yanshen; Wang, Zhanhui; Zhang, Suxia; De Saeger, Sarah; Zhou, Jinhui; Li, Yi; De Boevre, Marthe

2017-12-27

To explore differences of zearalenone (ZEN) metabolism between various species, phase I and II metabolism by liver microsomes of animals and human were investigated using ultra high-pressure liquid chromatography-quadrupole/time-of-flight mass spectrometry (UHPLC-Q/TOF MS). A total of 24 metabolites were identified, among which 12 were reported for the first time. Reduction, hydroxylation, and glucuronidation were the major metabolic pathways of ZEN, and significant differences in various species were also observed. Reduction was the main reaction in swine and human, whereas hydroxylation was predominant in rats, chickens, goats, and cows in in vitro systems. Furthemore, in vivo metabolism of ZEN in rats and chickens was investigated, and 23 and 6 metabolites were identified in each species, respectively. Reduction, hydroxylation, and glucuronidation were the major metabolic pathways in rats, while reduction and sulfation predominated in chickens. These results further enrich the biotransformation profile of ZEN, providing a helpful reference for assessing the risks to animals and humans.

Recent advances of liquid chromatography-(tandem) mass spectrometry in clinical and forensic toxicology.

PubMed

Peters, Frank T

2011-01-01

Liquid chromatography (LC) coupled to mass spectrometry (MS) or tandem mass spectrometry (MS/MS) has become increasingly important in clinical and forensic toxicology as well as doping control and is now a robust and reliable technique for routine analysis in these fields. In recent years, methods for LC-MS(/MS)-based systematic toxicological analysis using triple quadrupole or ion trap instruments have been considerably improved and a new screening approach based on high-resolution MS analysis using benchtop time-of-flight MS instruments has been developed. Moreover, many applications for so-called multi-target screening and/or quantification of drugs, poisons, and or their metabolites in various biomatrices have been published. The present paper will provide an overview and discuss these recent developments focusing on the literature published after 2006. Copyright © 2010 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Comprehensive identification and structural characterization of target components from Gelsemium elegans by high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry based on accurate mass databases combined with MS/MS spectra.

PubMed

Liu, Yan-Chun; Xiao, Sa; Yang, Kun; Ling, Li; Sun, Zhi-Liang; Liu, Zhao-Ying

2017-06-01

This study reports an applicable analytical strategy of comprehensive identification and structure characterization of target components from Gelsemium elegans by using high-performance liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QqTOF MS) based on the use of accurate mass databases combined with MS/MS spectra. The databases created included accurate masses and elemental compositions of 204 components from Gelsemium and their structural data. The accurate MS and MS/MS spectra were acquired through data-dependent auto MS/MS mode followed by an extraction of the potential compounds from the LC-QqTOF MS raw data of the sample. The same was matched using the databases to search for targeted components in the sample. The structures for detected components were tentatively characterized by manually interpreting the accurate MS/MS spectra for the first time. A total of 57 components have been successfully detected and structurally characterized from the crude extracts of G. elegans, but has failed to differentiate some isomers. This analytical strategy is generic and efficient, avoids isolation and purification procedures, enables a comprehensive structure characterization of target components of Gelsemium and would be widely applicable for complicated mixtures that are derived from Gelsemium preparations. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Broad screening and identification of β-agonists in feed and animal body fluid and tissues using ultra-high performance liquid chromatography-quadrupole-orbitrap high resolution mass spectrometry combined with spectra library search.

PubMed

Li, Tingting; Cao, Jingjing; Li, Zhen; Wang, Xian; He, Pingli

2016-02-01

Broad screening and identification of β-agonists in feed, serum, urine, muscle and liver samples was achieved in a quick and highly sensitive manner using ultra high performance liquid chromatography-quadrupole-orbitrap high resolution mass spectrometry (UHPLC-Q-Orbitrap HRMS) combined with a spectra library search. Solid-phase extraction technology was employed for sample purification and enrichment. After extraction and purification, the samples were analyzed using a Q-Orbitrap high-resolution mass spectrometer under full-scan and data-dependent MS/MS mode. The acquired mass spectra were compared with an in-house library (compound library and MS/MS mass spectral library) built with TraceFinder Software which contained the M/Z of the precursor ion, chemical formula, retention time, character fragment ions and the entire MS/MS spectra of 32 β-agonist standards. Screening was achieved by comparing 5 key mass spectral results and positive matches were marked. Using the developed method, the identification results from 10 spiked samples and 238 actual samples indicated that only 2% of acquired mass spectra produced false identities. The method validation results showed that the limit of detection ranged from 0.021-3.854 μg kg(-1)and 0.015-1.198 ng mL(-1) for solid and liquid samples, respectively. Copyright © 2015 Elsevier Ltd. All rights reserved.

Compound-Specific Chlorine Isotope Analysis of Tetrachloromethane and Trichloromethane by Gas Chromatography-Isotope Ratio Mass Spectrometry vs Gas Chromatography-Quadrupole Mass Spectrometry: Method Development and Evaluation of Precision and Trueness.

PubMed

Heckel, Benjamin; Rodríguez-Fernández, Diana; Torrentó, Clara; Meyer, Armin; Palau, Jordi; Domènech, Cristina; Rosell, Mònica; Soler, Albert; Hunkeler, Daniel; Elsner, Martin

2017-03-21

Compound-specific chlorine isotope analysis of tetrachloromethane (CCl 4 ) and trichloromethane (CHCl 3 ) was explored by both, gas chromatography-isotope ratio mass spectrometry (GC-IRMS) and GC-quadrupole MS (GC-qMS), where GC-qMS was validated in an interlaboratory comparison between Munich and Neuchâtel with the same type of commercial GC-qMS instrument. GC-IRMS measurements analyzed CCl isotopologue ions, whereas GC-qMS analyzed the isotopologue ions CCl 3 , CCl 2 , CCl (of CCl 4 ) and CHCl 3 , CHCl 2 , CHCl (of CHCl 3 ), respectively. Lowest amount dependence (good linearity) was obtained (i) in H-containing fragment ions where interference of 35 Cl- to 37 Cl-containing ions was avoided; (ii) with tuning parameters favoring one predominant rather than multiple fragment ions in the mass spectra. Optimized GC-qMS parameters (dwell time 70 ms, 2 most abundant ions) resulted in standard deviations of 0.2‰ (CHCl 3 ) and 0.4‰ (CCl 4 ), which are only about twice as large as 0.1‰ and 0.2‰ for GC-IRMS. To compare also the trueness of both methods and laboratories, samples from CCl 4 and CHCl 3 degradation experiments were analyzed and calibrated against isotopically different reference standards for both CCl 4 and CHCl 3 (two of each). Excellent agreement confirms that true results can be obtained by both methods provided that a consistent set of isotopically characterized reference materials is used.

Structural characterization of monoterpene indole alkaloids in ethanolic extracts of Rauwolfia species by liquid chromatography with quadrupole time-of-flight mass spectrometry.

PubMed

Kumar, Sunil; Singh, Awantika; Bajpai, Vikas; Srivastava, Mukesh; Singh, Bhim Pratap; Kumar, Brijesh

2016-12-01

Rauwolfia species (Apocynaceae) are medicinal plants well known worldwide due to its potent bioactive monoterpene indole alkaloids (MIAs) such as reserpine, ajmalicine, ajmaline, serpentine and yohimbine. Reserpine, ajmalicine and ajmaline are powerful antihypertensive, tranquilizing agents used in hypertension. Yohimbine is an aphrodisiac used in dietary supplements. As there is no report on the comparative and comprehensive phytochemical investigation of the roots of Rauwolfia species, we have developed an efficient and reliable liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for ethanolic root extract of Rauwolfia species to elucidate the fragmentation pathways for dereplication of bioactive MIAs using high-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (HPLC-ESI-QTOF-MS/MS) in positive ion mode. We identified and established diagnostic fragment ions and fragmentation pathways using reserpine, ajmalicine, ajmaline, serpentine and yohimbine. The MS/MS spectra of reserpine, ajmalicine, and ajmaline showed C -ring-cleavage whereas E -ring cleavage was observed in serpentine via Retro Diels Alder (RDA). A total of 47 bioactive MIAs were identified and characterized on the basis of their molecular formula, exact mass measurements and MS/MS analysis. Reserpine, ajmalicine, ajmaline, serpentine and yohimbine were unambiguously identified by comparison with their authentic standards and other 42 MIAs were tentatively identified and characterized from the roots of Rauwolfia hookeri, Rauwolfia micrantha, Rauwolfia serpentina, Rauwolfia verticillata, Rauwolfia tetraphylla and Rauwolfia vomitoria . Application of LC-MS followed by principal component analysis (PCA) has been successfully used to discriminate among six Rauwolfia species.

Mass Spectrometry Identification of N-Chlorinated Dipeptides in Drinking Water.

PubMed

Huang, Guang; Jiang, Ping; Li, Xing-Fang

2017-04-04

We report the identification of N-chlorinated dipeptides as chlorination products in drinking water using complementary high-resolution quadrupole time-of-flight (QTOF) and quadrupole ion-trap mass spectrometry techniques. First, three model dipeptides, tyrosylglycine (Tyr-Gly), tyrosylalanine (Tyr-Ala), and phenylalanylglycine (Phe-Gly), reacted with sodium hypochlorite, and these reaction solutions were analyzed by QTOF. N-Cl-Tyr-Gly, N,N-di-Cl-Tyr-Gly, N-Cl-Phe-Gly, N,N-di-Cl-Phe-Gly, N-Cl-Tyr-Ala, and N,N-di-Cl-Tyr-Ala were identified as the major products based on accurate masses, 35 Cl/ 37 Cl isotopic patterns, and MS/MS spectra. These identified N-chlorinated dipeptides were synthesized and found to be stable in water over 10 days except N,N-di-Cl-Phe-Gly. To enable sensitive detection of N-chlorinated dipeptides in authentic water, we developed a high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method with multiple reaction monitoring (MRM) mode. N-Cl-Tyr-Gly, N,N-di-Cl-Tyr-Gly, N-Cl-Phe-Gly, N-Cl-Tyr-Ala, and N,N-di-Cl-Tyr-Ala along with their corresponding dipeptides were detected in authentic tap water samples. The dipeptides were clearly detected in the raw water, but the N-chlorinated dipeptides were at background levels. These results suggest that the N-chlorinated dipeptides are produced by chlorination. This study has identified N-chlorinated dipeptides as new disinfection byproducts in drinking water. The strategy developed in this study can be used to identify chlorination products of other peptides in drinking water.

Identification of pesticide transformation products in agricultural soils using liquid chromatography/quadrupole-time-of-flight mass spectrometry.

PubMed

Padilla-Sánchez, Juan A; Michael Thurman, E; Plaza-Bolaños, Patricia; Ferrer, Imma

2012-05-15

A study of pesticide transformation products (TPs) was carried out in soils of agricultural areas working under integrated pest management programs (IPMs). Bupirimate and cyromazine were the pesticides detected in soils after an initial pre-screening. The aim of this work was the identification of relevant TPs of these two pesticides. Soil samples were extracted by pressurized liquid extraction (PLE), using a mixture of ethyl acetate/methanol (3:1, v/v), and analyzed by ultra-high-pressure liquid chromatography coupled to hybrid quadrupole-time-of-flight mass spectrometry (UHPLC-QTOF-MS). For confirmation purposes, tandem mass spectrometry (MS(2) ) experiments were carried out using QTOF-MS, obtaining specific fragment structures of the pesticides and their degradates. Retention times and exact masses of the protonated molecules were used for the identification of the pesticides bupirimate (m/z 317.1642) and cyromazine (m/z 167.1040) and their respective TPs, namely ethirimol (m/z 210.1601) and melamine (m/z 127.0727). A novel strategy using pseudo-MS(3) experiments was developed to confirm the structure of bupirimate TP (ethirimol). This strategy consists of generating the particular TP in the ion source, via collision-induced fragmentation, and then performing MS/MS to the fragment ion formed in-source. Ethirimol and melamine were identified as degradation products of bupirimate and cyromazine, respectively. The study was applied to the analysis of 15 agricultural soil samples finding bupirimate and ethirimol in seven samples, cyromazine in one sample and melamine in four samples. Copyright © 2012 John Wiley & Sons, Ltd.

Determination of suspected allergens in cosmetic products by headspace-programmed temperature vaporization-fast gas chromatography-quadrupole mass spectrometry.

PubMed

del Nogal Sánchez, Miguel; Pérez-Pavón, José Luis; Moreno Cordero, Bernardo

2010-07-01

In the present work, a strategy for the qualitative and quantitative analysis of 24 volatile compounds listed as suspected allergens in cosmetics by the European Union is reported. The list includes benzyl alcohol, limonene, linalool, methyl 2-octynoate, beta-citronellol, geraniol, citral (two isomers), 7-hydroxycitronellal, anisyl alcohol, cinnamal, cinnamyl alcohol, eugenol, isoeugenol (two isomers), coumarin, alpha-isomethyl ionone, lilial, alpha-amylcinnamal, lyral, alpha-amylcinnamyl alcohol, farnesol (three isomers), alpha-hexyl cinnamal, benzyl cinnamate, benzyl benzoate, and benzyl salicylate. The applicability of a headspace (HS) autosampler in combination with a gas chromatograph (GC) equipped with a programmable temperature vaporizer (PTV) and a quadrupole mass spectrometry (qMS) detector is explored. By using a headspace sampler, sample preparation is reduced to introducing the sample into the vial. This reduces the analysis time and the experimental errors associated with this step of the analytical process. Two different injection techniques were used: solvent-vent injection and hot-split injection. The first offers a way to improve sensitivity at the same time maintaining the simple headspace instrumentation and it is recommended for compounds at trace levels. The use of a liner packed with Tenax-TA allowed the compounds of interest to be retained during the venting process. The signals obtained when hot-split injection was used allowed quantification of all the compounds according to the thresholds of the European Cosmetics Directive. Monodimensional gas chromatography coupled to a conventional quadrupole mass spectrometry detector was used and the 24 analytes were separated appropriately along a run time of about 12 min. Use of the standard addition procedure as a quantification technique overcame the matrix effect. It should be emphasized that the method showed good precision and accuracy. Furthermore, it is rapid, simple, and--in view of the results--highly suitable for the determination of suspected allergens in different cosmetic products.

Induced in-source fragmentation pattern of certain novel (1Z,2E)-N-(aryl)propanehydrazonoyl chlorides by electrospray mass spectrometry (ESI-MS/MS)

PubMed Central

2013-01-01

Background Collision induced dissociation (CID) in the triple quadrupole mass spectrometer system (QQQ) typically yields more abundant fragment ions than those produced with resonance excitation in the presence of helium gas in the ion trap mass spectrometer system (IT). Detailed product ion spectra can be obtained from one stage MS2 scan using the QQQ. In contrast, generating the same number of fragment ions in the ion trap requires multiple stages of fragmentation (MSn) using CID via in-trap resonance excitation with the associated time penalties and drop in sensitivity. Results The use of in-source fragmentation with electrospray ionization (ESI) followed by product ion scan (MS2) in a triple quadrupole mass spectrometer system, was demonstrated. This process enhances the qualitative power of tandem mass spectrometry to simulate the MS3 of ion trap for a comprehensive study of fragmentation mechanisms. A five pharmacologically significant (1Z, 2E)-N-arylpropanehydrazonoyl chlorides (3a-e) were chosen as model compounds for this study. In this work, detailed fragmentation pathways were elucidated by further dissociation of each fragment ion in the ion spectrum, essentially, by incorporating fragmentor voltage induced dissociation (in-source fragmentation) and isolation of fragments in a quadrupole cell Q1. Subsequently, CID occurs in cell, Q2, and fragment ions are analyzed in Q3 operated in product ion mode this process can be referred to as pseudo-MS3 scan mode. Conclusions This approach allowed unambiguous assignment of all fragment ions using tandem mass spectrometer and provided adequate sensitivity and selectivity. It is beneficial for structure determination of unknown trace components. The data presented in this paper provide useful information on the effect of different substituents on the ionization/fragmentation processes and can be used in the characterization of this important class of compounds. PMID:23351484

Aquatic plant-derived changes in oil sands naphthenic acid signatures determined by low-, high- and ultrahigh-resolution mass spectrometry.

PubMed

Headley, John V; Peru, Kerry M; Armstrong, Sarah A; Han, Xiumei; Martin, Jonathan W; Mapolelo, Mmilili M; Smith, Donald F; Rogers, Ryan P; Marshall, Alan G

2009-02-01

Mass spectrometry is a common tool for studying the fate of complex organic compound mixtures in oil sands processed water (OSPW), but a comparison of low-, high- ( approximately 10 000), and ultrahigh-resolution ( approximately 400 000) instrumentation for this purpose has not previously been made. High-resolution quadrupole time-of-flight mass spectrometry (QTOF MS) and ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), with negative-ion electrospray ionization, provided evidence for the selective dissipation of components in OSPW. Dissipation of oil sands naphthenic acids (NAs with general formula C(n)H(2n+z)O(2) where n is the number of carbon atoms, and Z is zero or a negative even number describing the number of rings) was masked (by components such as fatty acids, O(3), O(5), O(6), O(7), SO(2), SO(3), SO(4), SO(5), SO(6), and NO(4) species) at low resolution (1000) when using a triple quadrupole mass spectrometer. Changes observed in the relative composition of components in OSPW appear to be due primarily to the presence of plants, specifically cattails (Typha latifolia) and their associated microorganisms. The observed dissipation included a range of heteratomic species containing O(2), O(3), O(4), and O(5), present in Athabasca oil sands acid extracts. For the heteratomic O(2) species, namely naphthenic acids, an interesting structural relationship suggests that low and high carbon number NAs are dissipated by the plants preferentially, with a minimum around C(14)/C(15). Other heteratomic species containing O(6), O(7), SO(2), SO(3), SO(4), SO(5), SO(6), and NO(4) appear to be relatively recalcitrant to the cattails and were not dissipated to the same extent in planted systems. Copyright 2009 John Wiley & Sons, Ltd.

Comprehensive analysis of chemical constituents in Xingxiong injection by high performance liquid chromatography coupled with mass spectrometry.

PubMed

Guo, Long; Dou, Li-Li; Duan, Li; Liu, Ke; Bi, Zhi-Ming; Li, Ping; Liu, E-Hu

2015-09-01

Xingxiong injection (XXI) is a widely used Chinese herbal formula prepared by the folium ginkgo extract and ligustrazine for the treatment of cardiovascular and cerebrovascular diseases. Compared with the pharmacological studies, chemical analysis and quality control studies on this formula are relatively limited. In the present study, a high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (HPLC-QTOF MS) method was applied to comprehensive analysis of constituents in XXI. According to the fragmentation rules and previous reports, thirty ginkgo flavonoids, four ginkgo terpene lactones, and one alkaloid were identified. A high performance liquid chromatography coupled with triple quadrupole mass spectrometry (HPLC-QQQ MS) method was then applied to quantify ten major constituents in XXI. The method validation results indicated that the developed method had desirable specificity, linearity, precision and accuracy. The total contents of ginkgo flavonoids were about 22.05-25.51 μg·mL(-1) and the ginkgo terpene lactones amounts were about 4.41-8.70 μg·mL(-1) in six batches of XXI samples, respectively. Furthermore, cosine ratio algorithm and distance measurements were employed to evaluate the similarity of XXI samples, and the results demonstrated a high-quality consistency. This work could provide comprehensive information on the quality control of Xingxiong injection, which be helpful in the establishment of a rational quality control standard. Copyright © 2015 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.

Antioxidant activity and ultra-performance LC-electrospray ionization-quadrupole time-of-flight mass spectrometry for phenolics-based fingerprinting of Rose species: Rosa damascena, Rosa bourboniana and Rosa brunonii.

PubMed

Kumar, Neeraj; Bhandari, Pamita; Singh, Bikram; Bari, Shamsher S

2009-02-01

Roses are one of the most important groups of ornamental plants and their fruits and flowers are used in a wide variety of food, nutritional products and different traditional medicines. The antioxidant activity of methanolic extracts from fresh flowers of three rose species (Rosa damascena, Rosa bourboniana and Rosa brunonii) was evaluated by 1,1-diphenyl-2-picryl hydrazyl (DPPH) free-radical method. The ability to scavenge DPPH radical was measured by the discoloration of the solution. The methanolic extract from R. brunonii exhibited maximum free-radical-scavenging activity (64.5+/-0.38%) followed by R. bourboniana (51.8+/-0.46%) and R. damascena (43.6+/-0.25%) at 100 microg/ml. Simultaneously, ultra-performance liquid chromatography coupled with electrospray ionization-quadrupole time-of-flight mass spectrometry (UPLC-ESI-QTOF-MS) was used to study phenolic composition in the methanolic extracts from the fresh flowers of rose species. The phenolic constituents were further investigated by direct infusion-ESI-QTOF-MS/MS in negative ion mode. Characteristic Electrospray ionization tandem mass spectrometry (ESI-MS/MS) spectra with other diagnostic fragment ions generated by retro Diels-Alder (RDA) fragmentation pathways were recorded for the flavonoids. Distinct similarities were observed in the relative distribution of polyphenolic compounds among the three species. The dominance of quercetin, kaempferol and their glycosides was observed in all the three species.

Simultaneous Analysis of Iridoid Glycosides and Anthraquinones in Morinda officinalis Using UPLC-QqQ-MS/MS and UPLC-Q/TOF-MSE.

PubMed

Zhao, Xiangsheng; Wei, Jianhe; Yang, Meihua

2018-05-03

Morinda officinalis is an important herbal medicine and functional food, and its main constituents include anthraquinone and iridoid glycosides. Quantification of the main compounds is a necessary step to understand the quality and therapeutic properties of M. officinalis , but this has not yet been performed based on liquid chromatography/tandem mass spectrometry (LC-MS/MS). Analytes were extracted from M. officinalis by reflux method. Ultrahigh-performance liquid chromatography coupled with a triple quadrupole mass spectrometry (UPLC-QqQ-MS) using multiple reaction monitoring (MRM) mode was applied for quantification. Fragmentation pathways of deacetyl asperulosidic acid and rubiadin were investigated based on UPLC with quadrupole time-of-flight tandem mass spectrometry (Q/TOF-MS) in the MS E centroid mode. The method showed a good linearity over a wide concentration range (R² ≥ 0.9930). The limits of quantification of six compounds ranged from 2.6 to 27.57 ng/mL. The intra- and inter-day precisions of the investigated components exhibited an RSD within 4.5% with mean recovery rates of 95.32⁻99.86%. Contents of selected compounds in M. officinalis varied significantly depending on region. The fragmentation pathway of deacetyl asperulosidic and rubiadin was proposed. A selective and sensitive method was developed for determining six target compounds in M. officinalis by UPLC-MS/MS. Furthermore, the proposed method will be helpful for quality control and identification main compounds of M. officinalis .

Determination of (2)H-enrichment of rat brain interstitial fluid and rat plasma by headspace-gas-chromatography - quadrupole-mass-spectrometry.

PubMed

Eberl, Anita; Altendorfer-Kroath, Thomas; Kollmann, Denise; Birngruber, Thomas; Sinner, Frank; Raml, Reingard; Magnes, Christoph

2016-09-15

(2)H2O as nonradioactive, stable marker substance is commonly used in preclinical and clinical studies and the precise determination of (2)H2O concentration in biological samples is crucial. However, aside from isotope ratio mass spectrometry (IRMS), only a very limited number of methods to accurately measure the (2)H2O concentration in biological samples are routinely established until now. In this study, we present a straightforward method to accurately measure (2)H-enrichment of rat brain interstitial fluid (ISF) and rat plasma to determine the relative recovery of a cerebral open flow microperfusion (cOFM) probe, using headspace-gas-chromatography - quadrupole-mass-spectrometry. This method is based on basic-catalyzed hydrogen/deuterium exchange in acetone and detects the (2)H-labelled acetone directly by the headspace GC-MS. Small sample volumes and limited number of preparation steps make this method highly competitive. It has been fully validated. (2)H enriched to 8800 ppm in plasma showed an accuracy of 98.9% and %Relative Standard Deviation (RSD) of 3.1 with n = 18 over three days and with two operators. Similar performance was obtained for cerebral ISF enriched to 1100 ppm (accuracy: 96.5%, %RSD: 3.1). With this highly reproducible method we demonstrated the successful employment of (2)H2O as performance marker for a cOFM probe. Copyright © 2016. Published by Elsevier Inc.

Metabolomic analysis of swine urine treated with β2-agonists by ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry.

PubMed

Wu, Yuping; Bi, Yanfeng; Bingga, Gali; Li, Xiaowei; Zhang, Suxia; Li, Jiancheng; Li, Hui; Ding, Shuangyang; Xia, Xi

2015-06-26

The illegal use of β2-agonists in livestock production was previously detected by efficient methods based on mass spectrometry to control the residues of these drugs. Nevertheless, such methods still remain a challenging task for authorities who monitor these residues because the use of "cocktails" composed of mixtures of low amounts of several substances as well as the synthesis of new compounds of unknown structure prevent efficient prevention of illegal use of growth-promoting agents. Here, we outlined a metabolomics-based strategy for detecting the use of "cocktails" composed of mixtures of low amounts of three β2-agonists via urine profiling. Urine profiles of controls and swine treated with mixture of low amounts of three substances (clenbuterol, salbutamol, and ractopamine) were analyzed with ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry. The metabolic differences between controls and β2-agonists-treated groups were compared using multivariate data analysis. Fourteen metabolites were identified related with the β2-agonists treatment, while two co-biomarkers, 2-indolecarboxylic acid and fluorometholone acetate, either in single or "cocktails" of low-dose mixture of clenbuterol, salbutamol, and ractopamine, could be considered as diagnostic markers for the detection of illegal use of β2-agonists. The results of depletion study demonstrated that it is practical to use the markers for monitoring of β2-agonists. Copyright © 2015 Elsevier B.V. All rights reserved.

Direct determination of fatty acid esters of 3-chloro-1, 2-propanediol in edible vegetable oils by isotope dilution - ultra high performance liquid chromatography - triple quadrupole mass spectrometry.

PubMed

Li, Heli; Chen, Dawei; Miao, Hong; Zhao, Yunfeng; Shen, Jianzhong; Wu, Yongning

2015-09-04

A selective and sensitive ultra-high performance liquid chromatography - triple quadrupole mass spectrometry (UHPLC-MS/MS) method coupled with matrix solid phase dispersion (MSPD) extraction was developed for the direct determination of fatty acid esters of 3-chloro-1,2-propanediol (3-MCPD esters) in edible vegetable oils. The method integrated the isotope dilution technique, MSPD extraction and UHPLC - MS/MS analysis with multi-reaction monitoring mode (MRM). Matrix-matched calibration curves showed good linearity within the range of 0.01-10mgL(-1) with the correlation coefficient not less than 0.999. Limits of detection (LODs) and limit of quantification (LOQs) of the 3-MCPD esters fell into the range of 0.0001-0.02mgkg(-1) and 0.0004-0.05mgkg(-1), respectively. The recoveries for the spiked extra virgin olive oils ranged from 94.4% to 108.3%, with the relative standard deviations (RSD) ranging from 0.6% to 10.5%. The method was applied for the oil sample (T2642) of the official Food Analysis Performance Assessment Scheme (FAPAS) in 2014 and other real samples from supermarket, and the results showed that the present method was comparative to the gas chromatography-mass spectrometry (GC-MS) method based on the improved German Society for Fat Science (DGF) standard method C-III 18 (09) except for palm oil. Copyright © 2015. Published by Elsevier B.V.

Analytical characterization of bioactive N-benzyl-substituted phenethylamines and 5-methoxytryptamines.

PubMed

Brandt, Simon D; Elliott, Simon P; Kavanagh, Pierce V; Dempster, Nicola M; Meyer, Markus R; Maurer, Hans H; Nichols, David E

2015-04-15

Substances based on the N-(2-methoxybenzyl)phenethylamine template ('NBOMe' derivatives) play an important role in medicinal research but some of these derivatives have also appeared as 'research chemicals' for recreational use which has attracted attention worldwide. A major challenge associated with newly emerging substances includes the lack of analytical data and the ability to correctly identify positional isomers. Six N-benzylphenethylamines based on the 2,5-dimethoxy-4-iodophenethylamine structure ('25I') and twelve substituted N-benzyl-5-methoxytryptamines ('5MT') have been prepared and extensively characterized. Techniques used for characterization were gas chromatography/ion trap mass spectrometry in electron and chemical ionization mode, liquid chromatography/diode array detection (DAD), infrared spectroscopy, electrospray high mass accuracy quadrupole time-of-flight tandem mass spectrometry, and triple quadrupole tandem mass spectrometry. The characterization of 18 'NBOMe' compounds provided a comprehensive collection of chromatographic and spectral data. Four groups of three positional isomers, i.e. 25I-NB2OMe, 25I-NB3OMe, 25I-NB4OMe, 25I-NB2B, 25I-NB3B, 25I-NB4B and their 5-methoxytryptamine counterparts, were included and assessed for ability to obtain differentiation. Six meta-substituted N-benzyl derivatives of 5-methoxytryptamine (CF3, F, CH3, Cl, I, SCH3) were also studied. The implementation of mass spectral techniques was helpful for the differentiation between isomers, for example, when considering the difference in a number of ion ratios. This was considered beneficial in cases where chromatographic separation was only partially achieved under liquid chromatography (LC) conditions. The use of LC/DAD analysis was also found to be valuable for this particular purpose, which confirmed the integrative value of complementary techniques used in areas related to forensic toxicology. Copyright © 2015 John Wiley & Sons, Ltd.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Belov, Mikhail E.; Anderson, Gordon A.; Smith, Richard D.

Data-dependent selective external ion ejection with improved resolution is demonstrated with a 3.5 tesla FTICR instrument employing DREAMS (Dynamic Range Enhancement Applied to Mass Spectrometry) technology. To correct for the fringing rf-field aberrations each rod of the selection quadrupole has been segmented into three sections, so that ion excitation and ejection was performed by applying auxiliary rf-only waveforms in the region of the middle segments. Two different modes of external ion trapping and ejection were studied with the mixtures of model peptides and a tryptic digest of bovine serum albumin. A mass resolution of about 100 has been attained formore » rf-only dipolar ejection in a quadrupole operating at a Mathieu parameter q of{approx} 0.45. LC-ESI-DREAMS-FTICR analysis of a 0.1 mg/mL solution of bovine serum albumin digest resulted in detection of 82 unique tryptic peptides with mass measurement errors lower than 5 ppm, providing 100% sequence coverage of the protein.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Belov, Mikhail E.; Anderson, Gordon A.; Smith, Richard D.

Data-dependent selective external ion ejection with improved resolution is demonstrated with a 3.5 tesla FTICR instrument employing DREAMS (Dynamic Range Enhancement Applied to Mass Spectrometry) technology. To correct for the fringing rf-field aberrations each rod of the selection quadrupole has been segmented into three sections, so that ion excitation and ejection was performed by applying auxiliary rf-only waveforms in the region of the middle segments. Two different modes of external ion trapping and ejection were studied with the mixtures of model peptides and a tryptic digest of bovine serum albumin. A mass resolution of about 100 had been attained formore » rf-only dipolar ejection in a quadrupole operating at a Mathieu parameter q of ~0.45. LC-ESI-DREAMS-FTICR analysis of a 0.1 mg/mL solution of bovine serum albumin digest resulted in detection of 82 unique tryptic peptides with mass measurement errors lower than 5 ppm, providing 100 % sequence coverage of the protein.« less

Investigation of Ion Transmission Effects on Intact Protein Quantification in a Triple Quadrupole Mass Spectrometer

NASA Astrophysics Data System (ADS)

Wang, Evelyn H.; Appulage, Dananjaya Kalu; McAllister, Erin A.; Schug, Kevin A.

2017-09-01

Recently, direct intact protein quantitation using triple quadrupole mass spectrometry (QqQ-MS) and multiple reaction monitoring (MRM) was demonstrated (J. Am. Soc. Mass Spectrom. 27, 886-896 (2016)). Even though QqQ-MS is known to provide extraordinary detection sensitivity for quantitative analysis, we found that intact proteins exhibited a less than 5% ion transmission from the first quadrupole to the third quadrupole mass analyzer in the presence of zero collision energy (ZCE). With the goal to enhance intact protein quantitation sensitivity, ion scattering effects, proton transfer effects, and mass filter resolution widths were examined for their contributions to the lost signal. Protein standards myoglobin and ubiquitin along with small molecules reserpine and vancomycin were analyzed together with various collision induced dissociation (CID) gases (N2, He, and Ar) at different gas pressures. Mass resolution settings played a significant role in reducing ion transmission signal. By narrowing the mass resolution window by 0.35 m/z on each side, roughly 75%-90% of the ion signal was lost. The multiply charged proteins experienced additional proton transfer effects, corresponding to 10-fold signal reduction. A study of increased sensitivity of the method was also conducted with various MRM summation techniques. Although the degree of enhancement was analyte-dependent, an up to 17-fold increase in sensitivity was observed for ubiquitin using a summation of multiple MRM transitions. Biological matrix, human urine, and equine plasma were spiked with proteins to demonstrate the specificity of the method. This study provides additional insight into optimizing the use and sensitivity of QqQ-MS for intact protein quantification. [Figure not available: see fulltext.

Direct Visualization of Neurotransmitters in Rat Brain Slices by Desorption Electrospray Ionization Mass Spectrometry Imaging (DESI - MS)

NASA Astrophysics Data System (ADS)

Fernandes, Anna Maria A. P.; Vendramini, Pedro H.; Galaverna, Renan; Schwab, Nicolas V.; Alberici, Luciane C.; Augusti, Rodinei; Castilho, Roger F.; Eberlin, Marcos N.

2016-12-01

Mass spectrometry imaging (MSI) of neurotransmitters has so far been mainly performed by matrix-assisted laser desorption/ionization (MALDI) where derivatization reagents, deuterated matrix and/or high resolution, or tandem MS have been applied to circumvent problems with interfering ion peaks from matrix and from isobaric species. We herein describe the application of desorption electrospray ionization mass spectrometry imaging (DESI)-MSI in rat brain coronal and sagittal slices for direct spatial monitoring of neurotransmitters and choline with no need of derivatization reagents and/or deuterated materials. The amino acids γ-aminobutyric (GABA), glutamate, aspartate, serine, as well as acetylcholine, dopamine, and choline were successfully imaged using a commercial DESI source coupled to a hybrid quadrupole-Orbitrap mass spectrometer. The spatial distribution of the analyzed compounds in different brain regions was determined. We conclude that the ambient matrix-free DESI-MSI is suitable for neurotransmitter imaging and could be applied in studies that involve evaluation of imbalances in neurotransmitters levels.

Quantification of Global DNA Methylation Levels by Mass Spectrometry.

PubMed

Fernandez, Agustin F; Valledor, Luis; Vallejo, Fernando; Cañal, Maria Jesús; Fraga, Mario F

2018-01-01

Global DNA methylation was classically considered the relative percentage of 5-methylcysine (5mC) with respect to total cytosine (C). Early approaches were based on the use of high-performance separation technologies and UV detection. However, the recent development of protocols using mass spectrometry for the detection has increased sensibility and permitted the precise identification of peak compounds based on their molecular masses. This allows work to be conducted with much less genomic DNA starting material and also to quantify 5-hydroxymethyl-cytosine (5hmC), a recently identified form of methylated cytosine that could play an important role in active DNA demethylation. Here, we describe the protocol that we currently use in our laboratory to analyze 5mC and 5hmC by mass spectrometry. The protocol, which is based on the method originally developed by Le and colleagues using Ultra Performance Liquid Chromatography (UPLC) and mass spectrometry (triple Quadrupole (QqQ)) detection, allows for the rapid and accurate quantification of relative global 5mC and 5hmC levels starting from just 1 μg of genomic DNA, which allows for the rapid and accurate quantification of relative global 5mC and 5hmC levels.

Structures and Fragmentation Mechanisms of the Ions of Ethanol by Triple Quadrupole Mass Spectrometry.

DTIC Science & Technology

1982-07-15

structural information contained in deuterated sp ies is readily obtainable. Eth 1 ions ty stdied tnc) Vde (CH3CHOH?’., [CH CHOHJ. (CH2COH]r-% [CH 2COF...high and low energy systems involves electronic 18 and vibrational 19 excitation respectively, the amount of energy thus deposited must be approximately

Micro-pulverized extraction pretreatment for highly sensitive analysis of 11-nor-9-carboxy-Δ(9)-tetrahydrocannabinol in hair by liquid chromatography/tandem mass spectrometry.

PubMed

Kuwayama, Kenji; Miyaguchi, Hajime; Yamamuro, Tadashi; Tsujikawa, Kenji; Kanamori, Tatsuyuki; Iwata, Yuko T; Inoue, Hiroyuki

2015-11-30

A primary metabolite of Δ(9) -tetrahydrocannabinol, 11-nor-9-carboxytetrahydrocannabinol (THC-COOH), serves as an effective indicator for cannabis intake. According to the recommendations of the Society of Hair Testing, at least 0.2 pg/mg of THC-COOH (cut-off level) must be present in a hair sample to constitute a positive result in a drug test. Typically, hair is digested with an alkaline solution and is subjected to gas chromatography/tandem mass spectrometry (GC/MS/MS) with negative ion chemical ionization (NICI). It is difficult to quantify THC-COOH at the cut-off level using liquid chromatography/tandem mass spectrometry (LC/MS/MS) without acquisition of second-generation product ions in triple quadrupole-ion trap mass spectrometers, because large amounts of matrix components in the low-mass range produced by digestion interfere with the THC-COOH peak. Using the typical pretreatment method (alkaline dissolution) and micro-pulverized extraction (MPE) with a stainless bullet, we compared the quantification of THC-COOH using GC/MS/MS and LC/MS/MS. MPE reduced the amount of matrix components in the low-mass range and enabled the quantification of THC-COOH at 0.2 pg/mg using a conventional triple quadrupole liquid chromatograph coupled to a mass spectrometer. On the other hand, the MPE pretreatment was unsuitable for GC/MS/MS, probably due to matrix components in the high-mass range. The proper combination of pretreatments and instrumental analyses was shown to be important for detecting trace amounts of THC-COOH in hair. In MPE, samples can be prepared rapidly, and LC/MS/MS is readily available, unlike GC/MS/MS with NICI. The combination of MPE and LC/MS/MS might therefore be used in the initial screening for THC-COOH in hair prior to confirmatory analysis using GC/MS/MS with NICI. Copyright © 2015 John Wiley & Sons, Ltd.

Multiplatform Mass Spectrometry-Based Approach Identifies Extracellular Glycolipids of the Yeast Rhodotorula babjevae UCDFST 04-877.

PubMed

Cajka, Tomas; Garay, Luis A; Sitepu, Irnayuli R; Boundy-Mills, Kyria L; Fiehn, Oliver

2016-10-28

A multiplatform mass spectrometry-based approach was used for elucidating extracellular lipids with biosurfactant properties produced by the oleaginous yeast Rhodotorula babjevae UCDFST 04-877. This strain secreted 8.6 ± 0.1 g/L extracellular lipids when grown in a benchtop bioreactor fed with 100 g/L glucose in medium without addition of hydrophobic substrate, such as oleic acid. Untargeted reversed-phase liquid chromatography-quadrupole/time-of-flight mass spectrometry (QTOFMS) detected native glycolipid molecules with masses of 574-716 Da. After hydrolysis into the fatty acid and sugar components and hydrophilic interaction chromatography-QTOFMS analysis, the extracellular lipids were found to consist of hydroxy fatty acids and sugar alcohols. Derivatization and chiral separation gas chromatography-mass spectrometry (GC-MS) identified these components as d-arabitol, d-mannitol, (R)-3-hydroxymyristate, (R)-3-hydroxypalmitate, and (R)-3-hydroxystearate. In order to assemble these substructures back into intact glycolipids that were detected in the initial screen, potential structures were in-silico acetylated to match the observed molar masses and subsequently characterized by matching predicted and observed MS/MS fragmentation using the Mass Frontier software program. Eleven species of acetylated sugar alcohol esters of hydroxy fatty acids were characterized for this yeast strain.

Selective Fluorination and Separation of Metals with NF3 for Mass Spectrometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Clark, Richard A.; Barinaga, Charles J.; McNamara, Bruce K.

2016-03-01

We report recent progress on the development of a new methodology based on the generation of volatile metal fluorides through the use of nitrogen trifluoride (NF3), and the separation and measurement of these metal fluorides by electron ionization mass spectrometry. Though unreactive under ambient conditions, NF3 reacts selectively at specified temperatures with various metal-containing species to form volatile metal fluorides. Utilizing these species-dependent traits, elements of a sample may be sequentially produced and thus separated on-line. Metals were reacted inside a thermogravimetric analyzer, the gas outlet of which was directly coupled to a quadrupole mass spectrometer with an electron impactmore » ionization source via a molecular leak valve. We present results of this project including the electron ionization mass spectrum of gaseous tellurium hexafluoride.« less

Qualitative and quantitative temporal analysis of licit and illicit drugs in wastewater in Australia using liquid chromatography coupled to mass spectrometry.

PubMed

Bade, Richard; White, Jason M; Gerber, Cobus

2018-01-01

The combination of qualitative and quantitative bimonthly analysis of pharmaceuticals and illicit drugs using liquid chromatography coupled to mass spectrometry is presented. A liquid chromatography-quadrupole time of flight instrument equipped with Sequential Window Acquisition of all THeoretical fragment-ion spectra (SWATH) was used to qualitatively screen 346 compounds in influent wastewater from two wastewater treatment plants in South Australia over a 14-month period. A total of 100 compounds were confirmed and/or detected using this strategy, with 61 confirmed in all samples including antidepressants (amitriptyline, dothiepin, doxepin), antipsychotics (amisulpride, clozapine), illicit drugs (cocaine, methamphetamine, amphetamine, 3,4-methylenedioxymethamphetamine (MDMA)), and known drug adulterants (lidocaine and tetramisole). A subset of these compounds was also included in a quantitative method, analyzed on a liquid chromatography-triple quadrupole mass spectrometer. The use of illicit stimulants (methamphetamine) showed a clear decrease, levels of opioid analgesics (morphine and methadone) remained relatively stable, while the use of new psychoactive substances (methylenedioxypyrovalerone (MDPV) and Alpha PVP) varied with no visible trend. This work demonstrates the value that high-frequency sampling combined with quantitative and qualitative analysis can deliver. Graphical abstract Temporal analysis of licit and illicit drugs in South Australia.

Rapid screening of 35 new psychoactive substances by ion mobility spectrometry (IMS) and direct analysis in real time (DART) coupled to quadrupole time-of-flight mass spectrometry (QTOF-MS).

PubMed

Gwak, Seongshin; Almirall, Jose R

2015-10-01

The recent propagation of new psychoactive substances (NPS) has led to the development of new techniques for the rapid characterization of controlled substances in this category. A commercial bench-top ion mobility spectrometer (IMS) with a (63) Ni ionization source and a direct analysis in real time (DART) coupled to quadrupole time-of-flight (QTOF) were used for the rapid characterization of 35 NPS. The advantages of these techniques are fast response, ease of operation, and minimal sample preparation. The characteristic reduced mobilities of each substance are reported as are the mass spectra of the 35 compounds. The acquired product ion scan mass spectra were also compared to a library database constructed by QTOF with a electrospray ionization (ESI) source and showed a consistent relative abundance for each peak over time. A total of four seized drug samples provided by the local forensic laboratory were analyzed in order to demonstrate the utility of this approach. The results of this study suggest that both IMS and DART-QTOF are promising alternatives for the rapid screening and characterization of these new psychoactive substances. Copyright © 2015 John Wiley & Sons, Ltd.

Quantification of sterol lipids in plants by quadrupole time-of-flight mass spectrometry

PubMed Central

Wewer, Vera; Dombrink, Isabel; vom Dorp, Katharina; Dörmann, Peter

2011-01-01

Glycerolipids, sphingolipids, and sterol lipids constitute the major lipid classes in plants. Sterol lipids are composed of free and conjugated sterols, i.e., sterol esters, sterol glycosides, and acylated sterol glycosides. Sterol lipids play crucial roles during adaption to abiotic stresses and plant-pathogen interactions. Presently, no comprehensive method for sterol lipid quantification in plants is available. We used nanospray ionization quadrupole-time-of-flight mass spectrometry (Q-TOF MS) to resolve and identify the molecular species of all four sterol lipid classes from Arabidopsis thaliana. Free sterols were derivatized with chlorobetainyl chloride. Sterol esters, sterol glycosides, and acylated sterol glycosides were ionized as ammonium adducts. Quantification of molecular species was achieved in the positive mode after fragmentation in the presence of internal standards. The amounts of sterol lipids quantified by Q-TOF MS/MS were validated by comparison with results obtained with TLC/GC. Quantification of sterol lipids from leaves and roots of phosphate-deprived A. thaliana plants revealed changes in the amounts and molecular species composition. The Q-TOF method is far more sensitive than GC or HPLC. Therefore, Q-TOF MS/MS provides a comprehensive strategy for sterol lipid quantification that can be adapted to other tandem mass spectrometers. PMID:21382968

Characterization by high-performance liquid chromatography/electrospray ionization quadrupole time-of-flight mass spectrometry of the lipid fraction of Spirulina platensis pressurized ethanol extract.

PubMed

Herrero, Miguel; Vicente, María J; Cifuentes, Alejandro; Ibáñez, Elena

2007-01-01

Microalgae have been suggested as a potential source for new functional ingredients, making possible the development of new functional foods from natural origin. Among the natural ingredients, polyunsaturated fatty acids (PUFAs) have generally been identified as an interesting group of compounds with biological activity, mainly related to their anti-inflammatory properties. In this regard, the use of environmentally friendly extraction procedures (e.g. pressurized liquid extraction, PLE) to obtain such natural ingredients is also becoming necessary. In this work, an exhaustive characterization of the lipid fraction of a pressurized ethanolic extract of the microalga Spirulina platensis is carried out. To achieve this objective high-performance liquid chromatography (HPLC) coupled to quadrupole time-of-flight mass spectrometry (QTOF-MS) is employed. The use of the QTOF analyzer allows the selection and isolation of precursor ions as well as providing the high efficiency, sensitivity and mass accuracy required. By means of this powerful hyphenated technique, it was possible to identify several polar lipids in an extract of S. platensis (some of them, to our knowledge, described for the first time in this work), including four free fatty acids, four monogalactosyl monoacylglycerols, three phosphatidylglycerols and two sulfoquinovosyl diacylglycerols.

Digitally synthesized high purity, high-voltage radio frequency drive electronics for mass spectrometry.

PubMed

Schaefer, R T; MacAskill, J A; Mojarradi, M; Chutjian, A; Darrach, M R; Madzunkov, S M; Shortt, B J

2008-09-01

Reported herein is development of a quadrupole mass spectrometer controller (MSC) with integrated radio frequency (rf) power supply and mass spectrometer drive electronics. Advances have been made in terms of the physical size and power consumption of the MSC, while simultaneously making improvements in frequency stability, total harmonic distortion, and spectral purity. The rf power supply portion of the MSC is based on a series-resonant LC tank, where the capacitive load is the mass spectrometer itself, and the inductor is a solenoid or toroid, with various core materials. The MSC drive electronics is based on a field programmable gate array (FPGA), with serial peripheral interface for analog-to-digital and digital-to-analog converter support, and RS232/RS422 communications interfaces. The MSC offers spectral quality comparable to, or exceeding, that of conventional rf power supplies used in commercially available mass spectrometers; and as well an inherent flexibility, via the FPGA implementation, for a variety of tasks that includes proportional-integral derivative closed-loop feedback and control of rf, rf amplitude, and mass spectrometer sensitivity. Also provided are dc offsets and resonant dipole excitation for mass selective accumulation in applications involving quadrupole ion traps; rf phase locking and phase shifting for external loading of a quadrupole ion trap; and multichannel scaling of acquired mass spectra. The functionality of the MSC is task specific, and is easily modified by simply loading FPGA registers or reprogramming FPGA firmware.

Biomarkers to Assess Possible Biological Effects on Reproductive Potential, Immune Function, and Energetic Fitness of Bottlenose Dolphins Exposed to Sounds Consistent with Naval Sonars

DTIC Science & Technology

2013-09-30

ion modes. The resulting chromatograms were then processed using XCMS (alignment and peak picking ). The data were processed with in-house...UHPLC liquid chromatography Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry ( MS ). A standard method was developed for rapid analysis...extraction protocols and then implemented LC- MS / MS analyses on our Thermo Fisher Scientific TSQ Vantage triple quadrupole mass spectrometer. This

Conventional liquid chromatography/triple quadrupole mass spectrometer-based metabolite identification and semi-quantitative estimation approach in the investigation of dabigatran etexilate in vitro metabolism

PubMed Central

Hu, Zhe-Yi; Parker, Robert B.; Herring, Vanessa L.; Laizure, S. Casey

2012-01-01

Dabigatran etexilate (DABE) is an oral prodrug that is rapidly converted by esterases to dabigatran (DAB), a direct inhibitor of thrombin. To elucidate the esterase-mediated metabolic pathway of DABE, a high-performance liquid chromatography/mass spectrometer (LC-MS/MS)-based metabolite identification and semi-quantitative estimation approach was developed. To overcome the poor full-scan sensitivity of conventional triple quadrupole mass spectrometry, precursor-product ion pairs were predicted, to search for the potential in vitro metabolites. The detected metabolites were confirmed by the product ion scan. A dilution method was introduced to evaluate the matrix effects of tentatively identified metabolites without chemical standards. Quantitative information on detected metabolites was obtained using ‘metabolite standards’ generated from incubation samples that contain a high concentration of metabolite in combination with a correction factor for mass spectrometry response. Two in vitro metabolites of DABE (M1 and M2) were identified, and quantified by the semi-quantitative estimation approach. It is noteworthy that CES1 convert DABE to M1 while CES2 mediates the conversion of DABE to M2. M1 (or M2) was further metabolized to DAB by CES2 (or CES1). The approach presented here provides a solution to a bioanalytical need for fast identification and semi-quantitative estimation of CES metabolites in preclinical samples. PMID:23239178

Identification of metabolites of vindoline in rats using ultra-high performance liquid chromatography/quadrupole time-of-flight mass spectrometry.

PubMed

Zhang, Yuqian; Sun, Yupeng; Mu, Xiyan; Yuan, Lin; Wang, Qiao; Zhang, Lantong

2017-08-15

Vindoline (VDL) is an indole alkaloid, possessing hypoglycemic and vasodilator effects, and it is also the prodrug of many vinca alkaloids. In this paper, we analyzed in vivo (including plasma, urine, bile and faeces) and in vitro metabolic profile of VDL in rat with ultra-high performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF-MS/MS). The chromatographic separation was performed on a C 18 column with a mobile phase consisted of 3mM ammonium acetate buffer and acetonitrile at a flow rate of 300μL/min. The mass spectral analysis was conducted in a positive electrospray ionization mode, and on-line data acquisition method multiple mass defect filter (MMDF) combined with dynamic background subtraction (DBS) were used in the biological samples analysis to trace all the potential metabolites of VDL. Twenty-five metabolites of VDL were detected by comparing with the blank sample, of which there were 2 sulfate conjugates. These data suggested that the biotransformation of VDL was deacetylation, oxidation, deoxidization, methylation, dealkylation and sulfate conjugation. This study provides useful information for further study of the pharmacology and mechanism of VDL, meanwhile, the research method can be widely applied to speculate structural features of the metabolites of other vinca alkaloids. Copyright © 2017 Elsevier B.V. All rights reserved.

The Laser Ablation Ion Funnel: Sampling for in situ Mass Spectrometry on Mars

NASA Technical Reports Server (NTRS)

Johnson, Paul V.; Hodyss, Robert; Tang, Keqi; Brinckerhoff, William B.; Smith, Richard D.

2011-01-01

A considerable investment has been made by NASA and other space agencies to develop instrumentation suitable for in situ analytical investigation of extra terrestrial bodies including various mass spectrometers (time-of-flight, quadrupole ion trap, quadrupole mass filters, etc.). However, the front-end sample handling that is needed to collect and prepare samples for interrogation by such instrumentation remains underdeveloped. Here we describe a novel approach tailored to the exploration of Mars where ions are created in the ambient atmosphere via laser ablation and then efficiently transported into a mass spectrometer for in situ analysis using an electrodynamic ion funnel. This concept would enable elemental and isotopic analysis of geological samples with the analysis of desorbed organic material a possibility as well. Such an instrument would be suitable for inclusion on all potential missions currently being considered such as the Mid-Range Rover, the Astrobiology Field Laboratory, and Mars Sample Return (i.e., as a sample pre-selection triage instrument), among others.

An External Matrix-Assisted Laser Desorption Ionization Source for Flexible FT-ICR Mass Spectrometry Imaging with Internal Calibration on Adjacent Samples

NASA Astrophysics Data System (ADS)

Smith, Donald F.; Aizikov, Konstantin; Duursma, Marc C.; Giskes, Frans; Spaanderman, Dirk-Jan; McDonnell, Liam A.; O'Connor, Peter B.; Heeren, Ron M. A.

2011-01-01

We describe the construction and application of a new MALDI source for FT-ICR mass spectrometry imaging. The source includes a translational X-Y positioning stage with a 10 × 10 cm range of motion for analysis of large sample areas, a quadrupole for mass selection, and an external octopole ion trap with electrodes for the application of an axial potential gradient for controlled ion ejection. An off-line LC MALDI MS/MS run demonstrates the utility of the new source for data- and position-dependent experiments. A FT-ICR MS imaging experiment of a coronal rat brain section yields ˜200 unique peaks from m/z 400-1100 with corresponding mass-selected images. Mass spectra from every pixel are internally calibrated with respect to polymer calibrants collected from an adjacent slide.

Metabolite fingerprinting of Camptotheca acuminata and the HPLC-ESI-MS/MS analysis of camptothecin and related alkaloids.

PubMed

Montoro, Paola; Maldini, Mariateresa; Piacente, Sonia; Macchia, Mario; Pizza, Cosimo

2010-01-20

The major phytochemical constituents, namely, alkaloids, flavonoids and ellagic acid derivatives, of leaves of Camptotheca acuminata were identified using high performance liquid chromatography (HPLC) coupled with electrospray mass spectrometry (ESI-MS) in extracts of plants cultivated in Italy and collected at different growth stages. Alkaloids related to camptothecin were identified and quantified by HPLC coupled with ESI-tandem mass spectrometry (MS/MS) employing, respectively, an ion trap and a triple quadrupole mass analyser. The fragmentation patterns of alkaloids related to camptothecin were analysed and a specific Multiple Reaction Monitoring HPLC-MS/MS method was developed for the quantitative determination of these constituents. The described method provides high sensitivity and specificity for the characterisation and quantitative determination of the alkaloids in C. acuminata.

Carbon Isotopic Ratios of Amino Acids in Stardust-Returned Samples

NASA Technical Reports Server (NTRS)

Elsila, Jamie E.; Glavin, Daniel P.; Dworkin, Jason P.

2009-01-01

NASA's Stardust spacecraft returned to Earth samples from comet 81P/Wild 2 in January 2006. Preliminary examinations revealed the presence of a suite of organic compounds including several amines and amino acids, but the origin of these compounds could not be identified. Here. we present the carbon isotopic ratios of glycine and E-aminocaproic acid (EACH), the two most abundant amino acids observed, in Stardust-returned foil samples measured by gas chromatography-combustion-isotope ratio crass spectrometry coupled with quadrupole mass spectrometry (GC-QMS/IRMS).

Broad screening of illicit ingredients in cosmetics using ultra-high-performance liquid chromatography-hybrid quadrupole-Orbitrap mass spectrometry with customized accurate-mass database and mass spectral library.

PubMed

Meng, Xianshuang; Bai, Hua; Guo, Teng; Niu, Zengyuan; Ma, Qiang

2017-12-15

Comprehensive identification and quantitation of 100 multi-class regulated ingredients in cosmetics was achieved using ultra-high-performance liquid chromatography (UHPLC) coupled with hybrid quadrupole-Orbitrap high-resolution mass spectrometry (Q-Orbitrap HRMS). A simple, efficient, and inexpensive sample pretreatment protocol was developed using ultrasound-assisted extraction (UAE), followed by dispersive solid-phase extraction (dSPE). The cosmetic samples were analyzed by UHPLC-Q-Orbitrap HRMS under synchronous full-scan MS and data-dependent MS/MS (full-scan MS 1 /dd-MS 2 ) acquisition mode. The mass resolution was set to 70,000 FWHM (full width at half maximum) for full-scan MS 1 and 17,500 FWHM for dd-MS 2 stage with the experimentally measured mass deviations of less than 2ppm (parts per million) for quasi-molecular ions and 5ppm for characteristic fragment ions for each individual analyte. An accurate-mass database and a mass spectral library were built in house for searching the 100 target compounds. Broad screening was conducted by comparing the experimentally measured exact mass of precursor and fragment ions, retention time, isotopic pattern, and ionic ratio with the accurate-mass database and by matching the acquired MS/MS spectra against the mass spectral library. The developed methodology was evaluated and validated in terms of limits of detection (LODs), limits of quantitation (LOQs), linearity, stability, accuracy, and matrix effect. The UHPLC-Q-Orbitrap HRMS approach was applied for the analysis of 100 target illicit ingredients in 123 genuine cosmetic samples, and exhibited great potential for high-throughput, sensitive, and reliable screening of multi-class illicit compounds in cosmetics. Copyright © 2017 Elsevier B.V. All rights reserved.

Exploring Chemistry in Microcompartments Using Guided Droplet Collisions in a Branched Quadrupole Trap Coupled to a Single Droplet, Paper Spray Mass Spectrometer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jacobs, Michael I.; Davies, James F.; Lee, Lance

Recent studies suggest that reactions in aqueous microcompartments can occur at significantly different rates than those in the bulk. Most studies have used electrospray to generate a polydisperse source of highly charged microdroplets, leading to multiple confounding factors potentially influencing reaction rates (e.g., evaporation, charge, and size). Thus, the underlying mechanism for the observed enhancement remains unclear. We present a new type of electrodynamic balance - the branched quadrupole trap (BQT) - which can be used to study reactions in microdroplets in a controlled environment. The BQT allows for condensed phase chemical reactions to be initiated by colliding droplets withmore » different reactants and levitating the merged droplet indefinitely. The performance of the BQT is characterized in several ways. Sub-millisecond mixing times as fast as ~400 μs are measured for low velocity (~0.1 m/s) collisions of droplets with <40 μm diameters. The reaction of o-phthalaldehyde (OPA) with alanine in the presence of dithiolthreitol is measured using both fluorescence spectroscopy and single droplet paper spray mass spectrometry. The bimolecular rate constant for reaction of alanine with OPA is found to be 84 ± 10 and 67 ± 6 M -1s -1 in a 30 μm radius droplet and bulk solution, respectively, which demonstrates that bimolecular reaction rate coefficients can be quantified using merged microdroplets and that merged droplets can be used to study rate enhancements due to compartmentalization. Products of the reaction of OPA with alanine are detected in single droplets using paper spray mass spectrometry. Finally, we demonstrate that single droplets with <100 pg of analyte can easily be studied using single droplet mass spectrometry.« less

Exploring Chemistry in Microcompartments Using Guided Droplet Collisions in a Branched Quadrupole Trap Coupled to a Single Droplet, Paper Spray Mass Spectrometer

DOE PAGES

Jacobs, Michael I.; Davies, James F.; Lee, Lance; ...

2017-10-19

Recent studies suggest that reactions in aqueous microcompartments can occur at significantly different rates than those in the bulk. Most studies have used electrospray to generate a polydisperse source of highly charged microdroplets, leading to multiple confounding factors potentially influencing reaction rates (e.g., evaporation, charge, and size). Thus, the underlying mechanism for the observed enhancement remains unclear. We present a new type of electrodynamic balance - the branched quadrupole trap (BQT) - which can be used to study reactions in microdroplets in a controlled environment. The BQT allows for condensed phase chemical reactions to be initiated by colliding droplets withmore » different reactants and levitating the merged droplet indefinitely. The performance of the BQT is characterized in several ways. Sub-millisecond mixing times as fast as ~400 μs are measured for low velocity (~0.1 m/s) collisions of droplets with <40 μm diameters. The reaction of o-phthalaldehyde (OPA) with alanine in the presence of dithiolthreitol is measured using both fluorescence spectroscopy and single droplet paper spray mass spectrometry. The bimolecular rate constant for reaction of alanine with OPA is found to be 84 ± 10 and 67 ± 6 M -1s -1 in a 30 μm radius droplet and bulk solution, respectively, which demonstrates that bimolecular reaction rate coefficients can be quantified using merged microdroplets and that merged droplets can be used to study rate enhancements due to compartmentalization. Products of the reaction of OPA with alanine are detected in single droplets using paper spray mass spectrometry. Finally, we demonstrate that single droplets with <100 pg of analyte can easily be studied using single droplet mass spectrometry.« less

In situ location and U-Pb dating of small zircon grains in igneous rocks using laser ablation-inductively coupled plasma-quadrupole mass spectrometry

NASA Astrophysics Data System (ADS)

Sack, Patrick J.; Berry, Ron F.; Meffre, Sebastien; Falloon, Trevor J.; Gemmell, J. Bruce; Friedman, Richard M.

2011-05-01

A new U-Pb zircon dating protocol for small (10-50 μm) zircons has been developed using an automated searching method to locate zircon grains in a polished rock mount. The scanning electron microscope-energy-dispersive X ray spectrum-based automated searching method can routinely find in situ zircon grains larger than 5 μm across. A selection of these grains was ablated using a 10 μm laser spot and analyzed in an inductively coupled plasma-quadrupole mass spectrometer (ICP-QMS). The technique has lower precision (˜6% uncertainty at 95% confidence on individual spot analyses) than typical laser ablation ICP-MS (˜2%), secondary ion mass spectrometry (<1%), and isotope dilution-thermal ionization mass spectrometry (˜0.4%) methods. However, it is accurate and has been used successfully on fine-grained lithologies, including mafic rocks from island arcs, ocean basins, and ophiolites, which have traditionally been considered devoid of dateable zircons. This technique is particularly well suited for medium- to fine-grained mafic volcanic rocks where zircon separation is challenging and can also be used to date rocks where only small amounts of sample are available (clasts, xenoliths, dredge rocks). The most significant problem with dating small in situ zircon grains is Pb loss. In our study, many of the small zircons analyzed have high U contents, and the isotopic compositions of these grains are consistent with Pb loss resulting from internal α radiation damage. This problem is not significant in very young rocks and can be minimized in older rocks by avoiding high-U zircon grains.

Strategies to avoid false negative findings in residue analysis using liquid chromatography coupled to time-of-flight mass spectrometry.

PubMed

Kaufmann, Anton; Butcher, Patrick

2006-01-01

Liquid chromatography coupled to orthogonal acceleration time-of-flight mass spectrometry (LC/TOF) provides an attractive alternative to liquid chromatography coupled to triple quadrupole mass spectrometry (LC/MS/MS) in the field of multiresidue analysis. The sensitivity and selectivity of LC/TOF approach those of LC/MS/MS. TOF provides accurate mass information and a significantly higher mass resolution than quadrupole analyzers. The available mass resolution of commercial TOF instruments ranging from 10 000 to 18 000 full width at half maximum (FWHM) is not, however, sufficient to completely exclude the problem of isobaric interferences (co-elution of analyte ions with matrix compounds of very similar mass). Due to the required data storage capacity, TOF raw data is commonly centroided before being electronically stored. However, centroiding can lead to a loss of data quality. The co-elution of a low intensity analyte peak with an isobaric, high intensity matrix compound can cause problems. Some centroiding algorithms might not be capable of deconvoluting such partially merged signals, leading to incorrect centroids.Co-elution of isobaric compounds has been deliberately simulated by injecting diluted binary mixtures of isobaric model substances at various relative intensities. Depending on the mass differences between the two isobaric compounds and the resolution provided by the TOF instrument, significant deviations in exact mass measurements and signal intensities were observed. The extraction of a reconstructed ion chromatogram based on very narrow mass windows can even result in the complete loss of the analyte signal. Guidelines have been proposed to avoid such problems. The use of sub-2 microm HPLC packing materials is recommended to improve chromatographic resolution and to reduce the risk of co-elution. The width of the extraction mass windows for reconstructed ion chromatograms should be defined according to the resolution of the TOF instrument. Alternative approaches include the spiking of the sample with appropriate analyte concentrations. Furthermore, enhanced software, capable of deconvoluting partially merged mass peaks, may become available. Copyright (c) 2006 John Wiley & Sons, Ltd.

Development of an UPLC-MS/MS Sulfonamide Multi-residue Method and its Application to Water, Manure Slurry, and Soils from Swine Rearing Facilities

USDA-ARS?s Scientific Manuscript database

An analytical method was developed using ultra performance liquid chromatography-triple quadrupole-tandem mass spectrometry (UPLC-TQ-MS/MS) to simultaneously analyze 14 sulfonamides (SA) in six minutes. Despite the rapidity of the assay the system was properly re-equilibrated in this time. No carryo...

Simultaneous analysis of nucleobases, nucleosides and ginsenosides in ginseng extracts using supercritical fluid chromatography coupled with single quadrupole mass spectrometry.

PubMed

Huang, Yang; Zhang, Tingting; Zhao, Yumei; Zhou, Haibo; Tang, Guangyun; Fillet, Marianne; Crommen, Jacques; Jiang, Zhengjin

2017-09-10

Nucleobases, nucleosides and ginsenosides, which have a significant impact on the physiological activity of organisms, are reported to be the active components of ginseng, while they are less present in ginseng extracts. Few analytical methods have been developed so far to simultaneously analyze these three classes of compounds with different polarities present in ginseng extracts. In the present study, a simple and efficient analytical method was successfully developed for the simultaneous separation of 17 nucleobases, nucleosides and ginsenosides in ginseng extracts using supercritical fluid chromatography coupled with single quadrupole mass spectrometry (SFC-MS). The effect of various experimental factors on the separation performance, such as the column type, temperature and backpressure, the type of modifier and additive, and the concentration of make-up solvent were systematically investigated. Under the selected conditions, the developed method was successfully applied to the quality evaluation of 14 batches of ginseng extracts from different origins. The results obtained for the different batches indicate that this method could be employed for the quality assessment of ginseng extracts. Copyright © 2017 Elsevier B.V. All rights reserved.

Trace determination of 13 haloacetamides in drinking water using liquid chromatography triple quadrupole mass spectrometry with atmospheric pressure chemical ionization.

PubMed

Chu, Wenhai; Gao, Naiyun; Yin, Daqiang; Krasner, Stuart W; Templeton, Michael R

2012-04-27

The haloacetamides (HAcAms) are disinfection by-products (DBPs) in drinking water which are currently receiving increased scientific attention due to their elevated toxicity relative to regulated disinfection by-products. A simultaneous determination method of 13 HAcAms, combining solid-phase extraction (SPE) enrichment, liquid chromatographic (LC) separation, and triple quadrupole mass spectrometry (tqMS) detection with atmospheric pressure chemical ionization (APCI) using selective reaction monitoring in positive mode, was developed to measure HAcAms, including chlorinated, brominated, and iodinated analogs. Ammonium chloride and Oasis HLB were selected as the dechlorinating reagent and polymeric SPE sorbent of HAcAm samples. The used tqMS apparatus showed higher sensitivity for the studied HAcAms in the APCI mode than electrospray ionization. 13 HAcAms were separated by LC in 9.0 min, and the detection limits ranged from 7.6 to 19.7 ng/L. The SPE-LC/tqMS method was successfully applied to quantify 13 HAcAms in drinking water samples for the first time, and first indentified tribromoacetamide and chloroiodoacetamide as DBPs in drinking water. Copyright © 2012 Elsevier B.V. All rights reserved.

Screening of pharmaceuticals and illicit drugs in wastewater and surface waters of Spain and Italy by high resolution mass spectrometry using UHPLC-QTOF MS and LC-LTQ-Orbitrap MS.

PubMed

Bade, Richard; Rousis, Nikolaos I; Bijlsma, Lubertus; Gracia-Lor, Emma; Castiglioni, Sara; Sancho, Juan V; Hernandez, Felix

2015-12-01

The existence of pharmaceuticals and illicit drugs (PIDs) in environmental waters has led many analytical chemists to develop screening methods for monitoring purposes. Water samples can contain a huge number of possible contaminants, commonly at low concentrations, which makes their detection and identification problematic. Liquid chromatography coupled with high resolution mass spectrometry (LC-HRMS) has proven itself effective in the screening of environmental contaminants. The present work investigates the use of the most popular HRMS instruments, quadrupole time-of-flight and linear trap quadrupole-Orbitrap, from two different laboratories. A suspect screening for PIDs was carried out on wastewater (influent and effluent) and surface water samples from Castellón, Eastern Spain, and Cremona, Northern Italy, incorporating a database of 107 PIDs (including 220 fragment ions). A comparison between the findings of both instruments and of the samples was made which highlights the advantages and drawbacks of the strategies applied in each case. In total, 28 compounds were detected and/or identified by either/both instruments with irbesartan, valsartan, benzoylecgonine and caffeine being the most commonly found compounds across all samples.

Identification of absorbed constituents and in vivo metabolites in rats after oral administration of Physalis alkekengi var. franchetii by ultra-high-pressure liquid chromatography quadrupole time-of-flight mass spectrometry.

PubMed

Feng, Xinchi; Huo, Xiaoguang; Liu, Hongxia; Chai, Liwei; Ding, Liqin; Qiu, Feng

2018-03-01

The calyces of Physalis alkekengi var. franchetii (Chinese Lantern, JDL) are well-known as traditional Chinese medicine owing to its various therapeutic effects. However, the bioactive constituents responsible for the pharmacological effects of JDL and their metabolites in vivo are still unclear to date. In this paper, an ultra-high-pressure liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC/Q-TOF-MS/MS) method was established to identify absorbed constituents and in vivo metabolites in rat biological fluids after oral administration of JDL. Based on the proposed strategy, 33 compounds were observed in dosed rat biosamples. Twelve of 33 compounds were indicated as prototype components of JDL, and 21 compounds were predicted to be metabolites of JDL. Finally, the metabolic pathways were proposed, which were glucuronidation, sulfation, methylation and dehydroxylation for flavonoid constituents and sulfonation and hydroxylation for physalin consitituents. This is the first systematic study on the absorbed constituents and metabolic profiling of JDL and will provide a useful template for screening and characterizing the ingredients and metabolites of traditional Chinese medicine. Copyright © 2017 John Wiley & Sons, Ltd.

A Focused Multiple Reaction Monitoring (MRM) Quantitative Method for Bioactive Grapevine Stilbenes by Ultra-High-Performance Liquid Chromatography Coupled to Triple-Quadrupole Mass Spectrometry (UHPLC-QqQ).

PubMed

Hurtado-Gaitán, Elías; Sellés-Marchart, Susana; Martínez-Márquez, Ascensión; Samper-Herrero, Antonio; Bru-Martínez, Roque

2017-03-07

Grapevine stilbenes are a family of polyphenols which derive from trans -resveratrol having antifungal and antimicrobial properties, thus being considered as phytoalexins. In addition to their diverse bioactive properties in animal models, they highlight a strong potential in human health maintenance and promotion. Due to this relevance, highly-specific qualitative and quantitative methods of analysis are necessary to accurately analyze stilbenes in different matrices derived from grapevine. Here, we developed a rapid, sensitive, and specific analysis method using ultra-high-performance liquid chromatography coupled to triple-quadrupole mass spectrometry (UHPLC-QqQ) in MRM mode to detect and quantify five grapevine stilbenes, trans -resveratrol, trans -piceid, trans -piceatannol, trans -pterostilbene, and trans -ε-viniferin, whose interest in relation to human health is continuously growing. The method was optimized to minimize in-source fragmentation of piceid and to avoid co-elution of cis -piceid and trans -resveratrol, as both are detected with resveratrol transitions. The applicability of the developed method of stilbene analysis was tested successfully in different complex matrices including cellular extracts of Vitis vinifera cell cultures, reaction media of biotransformation assays, and red wine.

Comprehensive blood plasma lipidomics by liquid chromatography/quadrupole time-of-flight mass spectrometry.

PubMed

Sandra, Koen; Pereira, Alberto Dos Santos; Vanhoenacker, Gerd; David, Frank; Sandra, Pat

2010-06-18

A lipidomics strategy, combining high resolution reversed-phase liquid chromatography (RPLC) with high resolution quadrupole time-of-flight mass spectrometry (QqTOF), is described. The method has carefully been assessed in both a qualitative and a quantitative fashion utilizing human blood plasma. The inherent low technical variability associated with the lipidomics method allows to measure 65% of the features with an intensity RSD value below 10%. Blood plasma lipid spike-in experiments demonstrate that relative concentration differences smaller than 25% can readily be revealed by means of a t-test. Utilizing an advanced identification strategy, it is shown that the detected features mainly originate from (lyso-)phospholipids, sphingolipids, mono-, di- and triacylglycerols and cholesterol esters. The high resolution offered by the up-front RPLC step further allows to discriminate various isomeric species associated with the different lipid classes. The added value of utilizing a Jetstream electrospray ionization (ESI) source over a regular ESI source in lipidomics is for the first time demonstrated. In addition, the application of ultra high performance LC (UHPLC) up to 1200bar to extend the peak capacity or increase productivity is discussed. Copyright (c) 2010 Elsevier B.V. All rights reserved.

Multi-analysis strategy for metabolism of Andrographis paniculata in rat using liquid chromatography/quadrupole time-of-flight mass spectrometry.

PubMed

Li, Wenlan; Sun, Xiangming; Xu, Ying; Wang, Xuezhi; Bai, Jing; Ji, Yubin

2015-07-01

Compared with chemical drugs, it is a huge challenge to identify active ingredients of multicomponent traditional Chinese medicine (TCM). For most TCMs, metabolism investigation of absorbed constituents is a feasible way to clarify the active material basis. Although Andrographis paniculata (AP) has been extensively researched by domestic and foreign scholars, its metabolism has seldom been fully addressed to date. In this paper, high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry was applied to analysis and characterization of AP metabolism in rat urine and feces samples after oral administration of ethanol extract. The differences in metabolites and metabolic pathways between the two biological samples were further compared. The chemical structures of 20 components were tentatively identified from drug-treated biological samples, including six prototype components and 14 metabolites, which underwent such main metabolic pathways as hydrolyzation, hydrogenation, dehydroxylation, deoxygenation, methylation, glucuronidation, sulfonation and sulfation. Two co-existing components were found in urine and feces samples, suggesting that some ingredients' metabolic processes were not unique. This study provides a comprehensive report on the metabolism of AP in rats, which will be helpful for understanding its mechanism. Copyright © 2014 John Wiley & Sons, Ltd.

A fast and simple solid phase microextraction coupled with gas chromatography-triple quadrupole mass spectrometry method for the assay of urinary markers of glutaric acidemias.

PubMed

Naccarato, Attilio; Gionfriddo, Emanuela; Elliani, Rosangela; Sindona, Giovanni; Tagarelli, Antonio

2014-10-30

The analysis of characteristic urinary acidic markers such as glutaric, 3-hydroxyglutaric, 2-hydroxyglutaric, adipic, suberic, sebacic, ethylmalonic, 3-hydroxyisovaleric and isobutyric acid constitutes the recommended follow-up testing procedure for glutaric acidemia type 1 (GA-1) and type 2 (GA-2). The goal of the work herein presented is the development of a fast and simple method for the quantification of these biomarkers in human urine. The proposed analytical approach is based on the use of solid phase microextraction (SPME) combined with gas chromatography-triple quadrupole mass spectrometry (GC-QqQ-MS) afterward a rapid derivatization of acidic moieties by propyl chloroformate, propanol and pyridine. Trueness and precision of the proposed protocol, tested at 5, 30 and 80mgl -1 , provided satisfactory values: recoveries were in the range between 72% and 116% and the relative standard deviations (RSD%) were between 0.9% and 18% (except for isobutyric acid at 5mgl -1 ). The LOD values achieved by the proposed method ranged between 1.0 and 473μgl -1 . Copyright © 2014 Elsevier B.V. All rights reserved.

Novel fluorinated surfactants tentatively identified in firefighters using liquid chromatography quadrupole time-of-flight tandem mass spectrometry and a case-control approach.

PubMed

Rotander, Anna; Kärrman, Anna; Toms, Leisa-Maree L; Kay, Margaret; Mueller, Jochen F; Gómez Ramos, María José

2015-02-17

Fluorinated surfactant-based aqueous film-forming foams (AFFFs) are made up of per- and polyfluorinated alkyl substances (PFAS) and are used to extinguish fires involving highly flammable liquids. The use of perfluorooctanesulfonic acid (PFOS) and other perfluoroalkyl acids (PFAAs) in some AFFF formulations has been linked to substantial environmental contamination. Recent studies have identified a large number of novel and infrequently reported fluorinated surfactants in different AFFF formulations. In this study, a strategy based on a case-control approach using quadrupole time-of-flight tandem mass spectrometry (QTOF-MS/MS) and advanced statistical methods has been used to extract and identify known and unknown PFAS in human serum associated with AFFF-exposed firefighters. Two target sulfonic acids [PFOS and perfluorohexanesulfonic acid (PFHxS)], three non-target acids [perfluoropentanesulfonic acid (PFPeS), perfluoroheptanesulfonic acid (PFHpS), and perfluorononanesulfonic acid (PFNS)], and four unknown sulfonic acids (Cl-PFOS, ketone-PFOS, ether-PFHxS, and Cl-PFHxS) were exclusively or significantly more frequently detected at higher levels in firefighters compared to controls. The application of this strategy has allowed for identification of previously unreported fluorinated chemicals in a timely and cost-efficient way.

A network pharmacology-integrated metabolomics strategy for clarifying the difference between effective compounds of raw and processed Farfarae flos by ultra high-performance liquid chromatography-quadrupole-time of flight mass spectrometry.

PubMed

Ding, Mingya; Li, Zhen; Yu, Xie-An; Zhang, Dong; Li, Jin; Wang, Hui; He, Jun; Gao, Xiu-Mei; Chang, Yan-Xu

2018-07-15

This study aimed to clarify the difference between the effective compounds of raw and processed Farfarae flos using a network pharmacology-integrated metabolomics strategy. First, metabolomics data were obtained by ultra high-performance liquid chromatography-quadrupole-time of flight mass spectrometry (UHPLC-Q-TOF/MS). Then, metabolomics analysis was developed to screen for the influential compounds that were different between raw and processed Farfarae flos. Finally, a network pharmacology approach was applied to verify the activity of the screened compounds. As a result, 4 compounds (chlorogenic acid, caffeic acid, rutin and isoquercitrin) were successfully screened, identified, quantified and verified as the most influential effective compounds. They may synergistically inhibit the p38, JNK and ERK-mediated pathways, which would induce the inhibition of the expression of the IFA virus. The results revealed that the proposed network pharmacology-integrated metabolomics strategy was a powerful tool for discovering the effective compounds that were responsible for the difference between raw and processed Chinese herbs. Copyright © 2018 Elsevier B.V. All rights reserved.

Peptide profiling of Internet-obtained Cerebrolysin using high performance liquid chromatography - electrospray ionization ion trap and ultra high performance liquid chromatography - ion mobility - quadrupole time of flight mass spectrometry.

PubMed

Gevaert, Bert; D'Hondt, Matthias; Bracke, Nathalie; Yao, Han; Wynendaele, Evelien; Vissers, Johannes Petrus Cornelis; De Cecco, Martin; Claereboudt, Jan; De Spiegeleer, Bart

2015-09-01

Cerebrolysin, a parenteral peptide preparation produced by controlled digestion of porcine brain proteins, is an approved nootropic medicine in some countries. However, it is also easily and globally available on the Internet. Nevertheless, until now, its exact chemical composition was unknown. Using high performance liquid chromatography (HPLC) coupled to ion trap and ultra high performance liquid chromatography (UHPLC) coupled to quadrupole-ion mobility-time-of-flight mass spectrometry (Q-IM-TOF MS), combined with UniProt pig protein database search and PEAKS de novo sequencing, we identified 638 unique peptides in an Internet-obtained Cerebrolysin sample. The main components in this sample originate from tubulin alpha- and beta-chain, actin, and myelin basic protein. No fragments of known neurotrophic factors like glial cell-derived neurotrophic factor (GDNF), neurotrophin nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and ciliary neurotrophic factor (CNTF) were found, suggesting that the activities reported in the literature are likely the result of new, hitherto unknown cryptic peptides with nootropic properties. Copyright © 2015 John Wiley & Sons, Ltd.

Serum metabolic profiling study of lung cancer using ultra high performance liquid chromatography/quadrupole time-of-flight mass spectrometry.

PubMed

Li, Yanjie; Song, Xue; Zhao, Xinjie; Zou, Lijuan; Xu, Guowang

2014-09-01

Lung cancer is currently the leading cause of cancer-related mortality worldwide. It is, therefore, important to enhance understanding and add a new auxiliary detection tool of lung cancer. In this work, serum metabolic characteristics of lung cancer were investigated with a non-targeted metabolomics method. The metabolic profiling of 23 patients with lung cancer and 23 healthy controls were analyzed using ultra high performance liquid chromatography/quadrupole time of flight mass spectrometry (UPLC/Q-TOF MS). Partial least squares discriminant analysis (PLS-DA) model of the metabolic data allowed the clear separation of the lung cancer patients from the healthy controls. In total, 27 differential metabolites were identified, which were mostly related to the perturbation of lipid metabolism, including choline, free fatty acids, lysophosphatidylcholines, etc. Choline and linoleic acid were defined as one combinational biomarker using binary logistic regression, which was supported by the validation with a smaller sample-set (9 patients and 9 healthy controls). These findings show that LC/MS-based serum metabolic profiling has potential application in complementary identification of lung cancer patients, and could be a powerful tool for cancer research. Copyright © 2014 Elsevier B.V. All rights reserved.

Simultaneous determination of organophosphorus pesticides in fruits and vegetables using atmospheric pressure gas chromatography quadrupole-time-of-flight mass spectrometry.

PubMed

Cheng, Zhipeng; Dong, Fengshou; Xu, Jun; Liu, Xingang; Wu, Xiaohu; Chen, Zenglong; Pan, Xinglu; Gan, Jay; Zheng, Yongquan

2017-09-15

This paper describes the application of atmospheric pressure gas chromatography quadrupole-time-of-flight mass spectrometry for the simultaneous determination of organophosphorus pesticides in apple, pear, tomato, cucumber and cabbage. Soft ionization with atmospheric pressure ionization source was compared with traditional electron impact ionization (EI). The sensitivity of GC coupled to atmospheric pressure ionization (APGC) for all the analytes was enhanced by 1.0-8.2 times. The ionization modes with atmospheric pressure ionization source was studied by comparing the charge-transfer and proton-transfer conditions. The optimized QuEChERs method was used to pretreat the samples. The calibration curves were found linear from 10 to 1000μg/L, obtaining correlation coefficients higher than 0.9845. Satisfactory mean recovery values, in the range of 70.0-115.9%, and satisfactory precision, with all RSD r <19.7% and all RSD R values <19.5% at the three fortified concentration levels for all the fifteen OPPs. The results demonstrate the potential of APGC-QTOF-MS for routine quantitative analysis of organophosphorus pesticide in fruits and vegetables. Copyright © 2017 Elsevier Ltd. All rights reserved.

Application of characteristic ion filtering with ultra-high performance liquid chromatography quadrupole time of flight tandem mass spectrometry for rapid detection and identification of chemical profiling in Eucommia ulmoides Oliv.

PubMed

He, Mingzhen; Jia, Jia; Li, Junmao; Wu, Bei; Huang, Wenping; Liu, Mi; Li, Yan; Yang, Shilin; Ouyang, Hui; Feng, Yulin

2018-06-15

Efficient targeted identification of chemical constituents from traditional Chinese medicine is still a major challenge. In this study, we used a characteristic ion filtering strategy to characterize compounds of Eucommia ulmoides Oliv. by ultra-high performance liquid chromatography quadrupole time of flight tandem mass spectrometry (UHPLC-ESI-Q-TOF-MS/MS). By using the ion filtering approach, target constituents of Eucommia ulmoides Oliv. were easily tentatively identified from the enormous LC/MS data set. The strategy consisted of the following three steps: 1) To establishing a characteristic ion database by diagnostic product ions or neutral loss fragments; 2) To evaluate the structural information of the compounds by high-resolution diagnostic characteristic ion filtering; 3) To confirm the different classes by chemical profiling according to their MS/MS spectra. In this study, characteristic ions are summarized as five major groups of compounds in Eucommia ulmoides Oliv. In total, 113 compounds were tentatively identified, including 23 potentially novel compounds. The results form a foundation for the quality control and chemical basis of Eucommia ulmoides Oliv. Copyright © 2018 Elsevier B.V. All rights reserved.

Systematic Analysis of Absorbed Anti-Inflammatory Constituents and Metabolites of Sarcandra glabra in Rat Plasma Using Ultra-High-Pressure Liquid Chromatography Coupled with Linear Trap Quadrupole Orbitrap Mass Spectrometry

PubMed Central

Li, Xiong; Zhao, Jin; Liu, Jianxing; Li, Geng; Zhao, Ya; Zeng, Xing

2016-01-01

Ultra-high-pressure liquid chromatography (UHPLC) was coupled with linear ion trap quadrupole Orbitrap mass spectrometry (LTQ-Orbitrap) and was used for the first time to systematically analyze the absorbed components and metabolites in rat plasma after oral administration of the water extract of Sarcandra glabra. This extract is a well-known Chinese herbal medicine for the treatment of inflammation and immunity related diseases. The anti-inflammatory activities of the absorbed components were evaluated by measuring nitric oxide (NO) production and proinflammatory genes expression in lipopolysaccharide (LPS)-stimulated murine RAW 264.7 macrophages. As a result, 54 components in Sarcandra glabra were detected in dosed rat plasma, and 36 of them were positively identified. Moreover, 23 metabolites were characterized and their originations were traced. Furthermore, 20 of the 24 studied components showed anti-inflammatory activities. These results provide evidence that this method efficiency detected constituents in plasma based on the anti-inflammatory mechanism of multiple components and would be a useful technique for screening multiple targets for natural medicine research. PMID:26974321

Hydrophilic interaction ultra-performance liquid chromatography coupled with triple-quadrupole tandem mass spectrometry for highly rapid and sensitive analysis of underivatized amino acids in functional foods.

PubMed

Zhou, Guisheng; Pang, Hanqing; Tang, Yuping; Yao, Xin; Mo, Xuan; Zhu, Shaoqing; Guo, Sheng; Qian, Dawei; Qian, Yefei; Su, Shulan; Zhang, Li; Jin, Chun; Qin, Yong; Duan, Jin-ao

2013-05-01

This work presented a new analytical methodology based on hydrophilic interaction ultra-performance liquid chromatography coupled with triple-quadrupole tandem mass spectrometry in multiple-reaction monitoring mode for analysis of 24 underivatized free amino acids (FAAs) in functional foods. The proposed method was first reported and validated by assessing the matrix effects, linearity, limit of detections and limit of quantifications, precision, repeatability, stability and recovery of all target compounds, and it was used to determine the nutritional substances of FAAs in ginkgo seeds and further elucidate the nutritional value of this functional food. The result showed that ginkgo seed turned out to be a good source of FAAs with high levels of several essential FAAs and to have a good nutritional value. Furthermore, the principal component analysis was performed to classify the ginkgo seed samples on the basis of 24 FAAs. As a result, the samples could be mainly clustered into three groups, which were similar to areas classification. Overall, the presented method would be useful for the investigation of amino acids in edible plants and agricultural products.

Quantitative analysis of flavanones from citrus fruits by using mesoporous molecular sieve-based miniaturized solid phase extraction coupled to ultrahigh-performance liquid chromatography and quadrupole time-of-flight mass spectrometry.

PubMed

Cao, Wan; Ye, Li-Hong; Cao, Jun; Xu, Jing-Jing; Peng, Li-Qing; Zhu, Qiong-Yao; Zhang, Qian-Yun; Hu, Shuai-Shuai

2015-08-07

An analytical procedure based on miniaturized solid phase extraction (SPE) and ultrahigh-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry was developed and validated for determination of six flavanones in Citrus fruits. The mesoporous molecular sieve SBA-15 as a solid sorbent was characterised by Fourier transform-infrared spectroscopy and scanning electron microscopy. Additionally, compared with reported extraction techniques, the mesoporous SBA-15 based SPE method possessed the advantages of shorter analysis time and higher sensitivity. Furthermore, considering the different nature of the tested compounds, all of the parameters, including the SBA-15 amount, solution pH, elution solvent, and the sorbent type, were investigated in detail. Under the optimum condition, the instrumental detection and quantitation limits calculated were less than 4.26 and 14.29ngmL(-1), respectively. The recoveries obtained for all the analytes were ranging from 89.22% to 103.46%. The experimental results suggested that SBA-15 was a promising material for the purification and enrichment of target flavanones from complex citrus fruit samples. Copyright © 2015 Elsevier B.V. All rights reserved.

Speciation of arsenic in marine food (Anemonia sulcata) by liquid chromatography coupled to inductively coupled plasma mass spectrometry and organic mass spectrometry.

PubMed

Contreras-Acuña, M; García-Barrera, T; García-Sevillano, M A; Gómez-Ariza, J L

2013-03-22

Arsenic species have been investigated in Anemonia sulcata, which is frequently consumed food staple in Spain battered in wheat flour and fried with olive oil. Speciation in tissue extracts was carried out by anion/cation exchange chromatography with inductively coupled plasma mass spectrometry (HPLC-(AEC/CEC)-ICP-MS). Three methods for the extraction of arsenic species were investigated (ultrasonic bath, ultrasonic probe and focused microwave) and the optimal one was applied. Arsenic speciation was carried out in raw and cooked anemone and the dominant species are dimethylarsinic acid (DMA(V)) followed by arsenobetaine (AB), As(V), monomethylarsonic acid (MA(V)), tetramethylarsonium ion (TETRA) and trimethylarsine oxide (TMAO). In addition, arsenocholine (AsC), glyceryl phosphorylarsenocholine (GPAsC) and dimethylarsinothioic acid (DMAS) were identified by liquid chromatography coupled to triple quadrupole mass spectrometry (HPLC-MS). These results are interesting since GPAsC has been previously reported in marine organisms after experimental exposure to AsC, but not in natural samples. In addition, this paper reports for the first time the identification of DMAS in marine food. Copyright © 2013 Elsevier B.V. All rights reserved.

Determination of selected non-authorized insecticides in peppers by liquid chromatography time-of-flight mass spectrometry and tandem mass spectrometry.

PubMed

Mezcua, Milagros; Ferrer, Carmen; García-Reyes, Juan F; Martínez-Bueno, María Jesús; Albarracín, Micaela; Claret, María; Fernández-Alba, Amadeo R

2008-05-01

In this work, two analytical methods based on liquid chromatography coupled to electrospray time-of-flight mass spectrometry (LC/ESI-TOFMS) and tandem mass spectrometry (LC/ESI-MS/MS) are described for the identification, confirmation and quantitation of three insecticides non-authorized in the European Union (nitenpyram, isocarbophos and isofenphos-methyl) but detected in recent monitoring programmes in pepper samples. The proposed methodologies involved a sample extraction procedure using liquid-liquid partition with acetonitrile followed by a cleanup step based on dispersive solid-phase extraction. Recovery studies performed on peppers spiked at different fortification levels (10 and 50 microg kg(-1)) yielded average recoveries in the range 76-100% with relative standard deviation (RSD) (%) values below 10%. Identification, confirmation and quantitation were carried out by LC/TOFMS and LC/MS/MS using a hybrid triple quadrupole linear ion trap (QqLIT) instrument in multiple-reaction monitoring (MRM) mode. The obtained limits of quantitation (LOQs) were in the range 0.1-5 microg kg(-1), depending on each individual technique. Finally, the proposed methods were successfully applied to the analysis of suspected pepper samples. Copyright (c) 2008 John Wiley & Sons, Ltd.

Tandem mass spectrometry of coprogen and deferoxamine hydroxamic siderophores.

PubMed

Simionato, Ana V C; de Souza, Gezimar D; Rodrigues-Filho, Edson; Glick, James; Vouros, Paul; Carrilho, Emanuel

2006-01-01

Mechanisms of fragmentation of hydroxamic siderophores are proposed comparing deuterated and nondeuterated samples. Standard siderophores (e.g. deferoxamine and coprogen) were directly injected into both ion trap and linear quadrupole mass spectrometers with electrospray ionization (ESI). Four and two fragmentation steps were carried out for deferoxamine and coprogen (analyzed by positive and negative ESI, respectively). Deferoxamine cleavages occurred in both peptide and hydroxamic bonds while the coprogen fragmentation pattern is more elaborate, since it contains Fe(III) in its structure.

Analysis of glyphosate and aminomethylphosphonic acid in leaves from Coffea arabica using high performance liquid chromatography with quadrupole mass spectrometry detection.

PubMed

Schrübbers, Lars C; Masís-Mora, Mario; Rojas, Elizabeth Carazo; Valverde, Bernal E; Christensen, Jan H; Cedergreen, Nina

2016-01-01

Glyphosate is a commonly applied herbicide in coffee plantations. Because of its non-selective mode of action it can damage the crop exposed through spray drift. Therefore, it is of interest to study glyphosate fate in coffee plants. The aim of this study was to develop an analytical method for accurate and precise quantification of glyphosate and its main metabolite aminomethylphosphonic acid (AMPA) at trace levels in coffee leaves using liquid chromatography with single-quadrupole mass spectrometry detection. The method is based on a two-step solid phase extraction (SPE) with an intermediate derivatization reaction using 9-fluorenylmethylchloroformate (FMOC). An isotope dilution method was used to account for matrix effects and to enhance the confidence in analyte identification. The limit of quantification (LOQ) for glyphosate and AMPA in coffee leaves was 41 and 111 μg kg(-1) dry weight, respectively. For the method optimization a design of experiments (DOE) approach was used. The sample clean-up procedure can be simplified for the analysis of less challenging matrices, for laboratories having a tandem mass spectrometry detector and for cases in which quantification limits above 0.1 mg kg(-1) are acceptable, which is often the case for glyphosate. The method is robust, possesses high identification confidence, while being suitable for most commercial and academic laboratories. All leaf samples from five coffee fields analyzed (n=21) contained glyphosate, while AMPA was absent. The simplified clean-up procedure was successfully validated for coffee leaves, rice, black beans and river water. Copyright © 2015 Elsevier B.V. All rights reserved.

Characterization, stoichiometry, and stability of salivary protein-tannin complexes by ESI-MS and ESI-MS/MS.

PubMed

Canon, Francis; Paté, Franck; Meudec, Emmanuelle; Marlin, Thérèse; Cheynier, Véronique; Giuliani, Alexandre; Sarni-Manchado, Pascale

2009-12-01

Numerous protein-polyphenol interactions occur in biological and food domains particularly involving proline-rich proteins, which are representative of the intrinsically unstructured protein group (IUP). Noncovalent protein-ligand complexes are readily detected by electrospray ionization mass spectrometry (ESI-MS), which also gives access to ligand binding stoichiometry. Surprisingly, the study of interactions between polyphenolic molecules and proteins is still an area where ESI-MS has poorly benefited, whereas it has been extensively applied to the detection of noncovalent complexes. Electrospray ionization mass spectrometry has been applied to the detection and the characterization of the complexes formed between tannins and a human salivary proline-rich protein (PRP), namely IB5. The study of the complex stability was achieved by low-energy collision-induced dissociation (CID) measurements, which are commonly implemented using triple quadrupole, hybrid quadrupole time-of-flight, or ion trap instruments. Complexes composed of IB5 bound to a model polyphenol EgCG have been detected by ESI-MS and further analyzed by MS/MS. Mild ESI interface conditions allowed us to observe intact noncovalent PRP-tannin complexes with stoichiometries ranging from 1:1 to 1:5. Thus, ESI-MS shows its efficiency for (1) the study of PRP-tannin interactions, (2) the determination of stoichiometry, and (3) the study of complex stability. We were able to establish unambiguously both their stoichiometries and their overall subunit architecture via tandem mass spectrometry and solution disruption experiments. Our results prove that IB5.EgCG complexes are maintained intact in the gas phase.

Fast and automated characterization of major constituents in rat biofluid after oral administration of Abelmoschus manihot extract using ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry and MetaboLynx.

PubMed

Guo, Jianming; Shang, Er-Xin; Duan, Jin-Ao; Tang, Yuping; Qian, Dawei; Su, Shulan

2010-02-01

In drug metabolism research, the setting up of a complex series of mass spectrometry experiments and the subsequent analysis of the large amounts of data produced are often time-consuming. In this paper, we describe a strategy using ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC/QTOFMS) with automated data analysis software (MetaboLynx) for fast analysis of the metabolic profile of flavonoids in Abelmoschus manihot. Rat plasma and urine samples collected 1 h and 0-12 h after oral administration of Abelmoschus manihot were analyzed by UPLC/QTOFMS within 15 min. The post-acquisition data were processed using MetaboLynx. With key parameters carefully set, MetaboLynx is able to show the presence of a wide range of metabolites with only a limited requirement for manual intervention and data interpretation time. A total of 16 and 38 metabolites were identified in plasma and urine compared with blank samples. The results indicated that methylation and glucuronidation after deglycosylation were the major metabolic pathways of flavonoid glycosides in Abelmoschus manihot. The present study provided important information about the metabolism of flavonoid glycosides in Abelmoschus manihot which will be helpful for fully understanding the mechanism of action of this herb. Furthermore, this work demonstrated the potential of the UPLC/QTOFMS approach using MetaboLynx for fast and automated identification of metabolites from Chinese herbal medicines. Copyright (c) 2010 John Wiley & Sons, Ltd.

Method for the elucidation of the elemental composition of low molecular mass chemicals using exact masses of product ions and neutral losses: application to environmental chemicals measured by liquid chromatography with hybrid quadrupole/time-of-flight mass spectrometry.

PubMed

Suzuki, Shigeru; Ishii, Tetsuko; Yasuhara, Akio; Sakai, Shinichi

2005-01-01

A method for elucidating the elemental compositions of low molecular weight chemicals, based primarily on mass measurements made using liquid chromatography (LC) with time-of-flight mass spectrometry (TOFMS) and quadrupole/time-of-flight mass spectrometry (LC/QTOFMS), was developed and tested for 113 chemicals of environmental interest with molecular masses up to approximately 400 Da. As the algorithm incorporating the method is not affected by differences in the instrument used, or by the ionization method and other ionization conditions, the method is useful not only for LC/TOFMS, but also for all kinds of mass spectra measured with higher accuracy and precision (uncertainties of a few mDa) employing all ionization methods and on-line separation techniques. The method involves calculating candidate compositions for intact ionized molecules (ionized forms of the sample molecule that have lost or gained no more than a proton, i.e., [M+H](+) or [M-H](-)) as well as for fragment ions and corresponding neutral losses, and eliminating those atomic compositions for the molecules that are inconsistent with the corresponding candidate compositions of fragment ions and neutral losses. Candidate compositions were calculated for the measured masses of the intact ionized molecules and of the fragment ions and corresponding neutral losses, using mass uncertainties of 2 and 5 mDa, respectively. Compositions proposed for the ionized molecule that did not correspond to the sum of the compositions of a candidate fragment ion and its corresponding neutral loss were discarded. One, 2-5, 6-10, 11-20, and >20 candidate compositions were found for 65%, 39%, 1%, 1%, and 0%, respectively, for the 124 ionized molecules formed from the 113 chemicals tested (both positive and negative ions were obtained from 11 of the chemicals). However, no candidate composition was found for 2% of the test cases (i.e., 3 chemicals), for each of which the measured mass of one of the product ions was in error by 5-6.7 mDa.

Qualification and initial characterization of a high-purity 233U spike for use in uranium analyses

DOE PAGES

Mathew, K. J.; Canaan, R. D.; Hexel, C.; ...

2015-08-20

Several high-purity 233U items potentially useful as isotope dilution mass spectrometry standards for safeguards, non-proliferation, and nuclear forensics measurements are identified and rescued from downblending. By preserving the supply of 233U materials of different pedigree for use as source materials for certified reference materials (CRMs), it is ensured that the safeguards community has high quality uranium isotopic standards required for calibration of the analytical instruments. One of the items identified as a source material for a high-purity CRM is characterized for the uranium isotope-amount ratios using thermal ionization mass spectrometry (TIMS). Additional verification measurements on this material using quadrupole inductivelymore » coupled plasma mass spectrometry (ICPMS) are also performed. As a result, the comparison of the ICPMS uranium isotope-amount ratios with the TIMS data, with much smaller uncertainties, validated the ICPMS measurement practices. ICPMS is proposed for the initial screening of the purity of items in the rescue campaign.« less

Separation of Opiate Isomers Using Electrospray Ionization and Paper Spray Coupled to High-Field Asymmetric Waveform Ion Mobility Spectrometry

NASA Astrophysics Data System (ADS)

Manicke, Nicholas E.; Belford, Michael

2015-05-01

One limitation in the growing field of ambient or direct analysis methods is reduced selectivity caused by the elimination of chromatographic separations prior to mass spectrometric analysis. We explored the use of high-field asymmetric waveform ion mobility spectrometry (FAIMS), an ambient pressure ion mobility technique, to separate the closely related opiate isomers of morphine, hydromorphone, and norcodeine. These isomers cannot be distinguished by tandem mass spectrometry. Separation prior to MS analysis is, therefore, required to distinguish these compounds, which are important in clinical chemistry and toxicology. FAIMS was coupled to a triple quadrupole mass spectrometer, and ionization was performed using either a pneumatically assisted heated electrospray ionization source (H-ESI) or paper spray, a direct analysis method that has been applied to the direct analysis of dried blood spots and other complex samples. We found that FAIMS was capable of separating the three opiate structural isomers using both H-ESI and paper spray as the ionization source.

Ripening-dependent metabolic changes in the volatiles of pineapple (Ananas comosus (L.) Merr.) fruit: I. Characterization of pineapple aroma compounds by comprehensive two-dimensional gas chromatography-mass spectrometry.

PubMed

Steingass, Christof Björn; Carle, Reinhold; Schmarr, Hans-Georg

2015-03-01

Qualitative ripening-dependent changes of pineapple volatiles were studied via headspace solid-phase microextraction and analyzed by comprehensive two-dimensional gas chromatography quadrupole mass spectrometry (HS-SPME-GC×GC-qMS). Early green-ripe stage, post-harvest ripened, and green-ripe fruits at the end of their commercial shelf-life were compared to air-freighted pineapples harvested at full maturity. In total, more than 290 volatiles could be identified by mass spectrometry and their linear retention indices. The majority of compounds comprise esters (methyl and ethyl esters of saturated and unsaturated fatty acids, acetates), terpenes, alcohols, aldehydes, 2-ketones, free fatty acids, and miscellaneous γ- and δ-lactones. The structured separation space obtained by GC×GC allowed revealing various homologous series of compound classes as well as clustering of sesquiterpenes. Post-harvest ripening increased the diversity of the volatile profile compared to both early green-ripe maturity stages and on-plant ripened fruits.

Mass cytometry: technique for real time single cell multitarget immunoassay based on inductively coupled plasma time-of-flight mass spectrometry.

PubMed

Bandura, Dmitry R; Baranov, Vladimir I; Ornatsky, Olga I; Antonov, Alexei; Kinach, Robert; Lou, Xudong; Pavlov, Serguei; Vorobiev, Sergey; Dick, John E; Tanner, Scott D

2009-08-15

A novel instrument for real time analysis of individual biological cells or other microparticles is described. The instrument is based on inductively coupled plasma time-of-flight mass spectrometry and comprises a three-aperture plasma-vacuum interface, a dc quadrupole turning optics for decoupling ions from neutral components, an rf quadrupole ion guide discriminating against low-mass dominant plasma ions, a point-to-parallel focusing dc quadrupole doublet, an orthogonal acceleration reflectron analyzer, a discrete dynode fast ion detector, and an 8-bit 1 GHz digitizer. A high spectrum generation frequency of 76.8 kHz provides capability for collecting multiple spectra from each particle-induced transient ion cloud, typically of 200-300 micros duration. It is shown that the transients can be resolved and characterized individually at a peak frequency of 1100 particles per second. Design considerations and optimization data are presented. The figures of merit of the instrument are measured under standard inductively coupled plasma (ICP) operating conditions (<3% cerium oxide ratio). At mass resolution (full width at half-maximum) M/DeltaM > 900 for m/z = 159, the sensitivity with a standard sample introduction system of >1.4 x 10(8) ion counts per second per mg L(-1) of Tb and an abundance sensitivity of (6 x 10(-4))-(1.4 x 10(-3)) (trailing and leading masses, respectively) are shown. The mass range (m/z = 125-215) and abundance sensitivity are sufficient for elemental immunoassay with up to 60 distinct available elemental tags. When <15 elemental tags are used, a higher sensitivity mode at lower resolution (M/DeltaM > 500) can be used, which provides >2.4 x 10(8) cps per mg L(-1) of Tb, at (1.5 x 10(-3))-(5.0 x 10(-3)) abundance sensitivity. The real-time simultaneous detection of multiple isotopes from individual 1.8 microm polystyrene beads labeled with lanthanides is shown. A real time single cell 20 antigen expression assay of model cell lines and leukemia patient samples immuno-labeled with lanthanide-tagged antibodies is presented.

Airborne mass spectrometers: four decades of atmospheric and space research at the Air Force research laboratory.

PubMed

Viggiano, A A; Hunton, D E

1999-11-01

Mass spectrometry is a versatile research tool that has proved to be extremely useful for exploring the fundamental nature of the earth's atmosphere and ionosphere and in helping to solve operational problems facing the Air Force and the Department of Defense. In the past 40 years, our research group at the Air Force Research Laboratory has flown quadrupole mass spectrometers of many designs on nearly 100 sounding rockets, nine satellites, three Space Shuttles and many missions of high-altitude research aircraft and balloons. We have also used our instruments in ground-based investigations of rocket and jet engine exhaust, combustion chemistry and microwave breakdown chemistry. This paper is a review of the instrumentation and techniques needed for space research, a summary of the results from many of the experiments, and an introduction to the broad field of atmospheric and space mass spectrometry in general. Copyright 1999 John Wiley & Sons, Ltd.

Determination of nandrolone and metabolites in urine samples from sedentary persons and sportsmen.

PubMed

Galán Martín, A M; Mariño, J I; García de Tiedra, M P; Marabé, J J; Caballero Loscos, M J; Mariño, M M

2001-09-25

Metabolites of nandrolone were determined in the urine of several sportsmen, sedentary and post-menopausal women by capillary gas chromatography-mass spectrometry quadrupole (GC-MS) and capillary gas chromatography mass-mass spectrometry ion trap (GC-MS-MS) methods. The method employed was GC-EI-MS with 17alpha-methyltestosterone as internal standard with ethyl ether extraction prior to selected ion monitoring of the bis(trimethylsilyl) ethers at ion masses m/z 405 and 420 for the nandrolone metabolites, and 418 and 403 for nandrolone derivative. Recovery for nandrolone, 19-norandrosterone (19-NA) and 19-noretiocholanolone (19-NE) was 97.20, 94.17 and 95.54%, respectively. Detection limits for nandrolone, 19-NA and 19-NE were 0.03, 0.01 and 0.06 ng/ml. Metabolites of nandrolone (19-NA and 19-NE) were found in 12.5% (n = 40) of sportsmen and 40% (n = 10) of post-menopausal women.

Characterization of ANFO explosive by high accuracy ESI(±)-FTMS with forensic identification on real samples by EASI(-)-MS.

PubMed

Hernandes, Vinicius Veri; Franco, Marcos Fernado; Santos, Jandyson Machado; Melendez-Perez, Jose J; de Morais, Damila Rodrigues; Rocha, Werickson Fortunato de Carvalho; Borges, Rodrigo; de Souza, Wanderley; Zacca, Jorge Jardim; Logrado, Lucio Paulo Lima; Eberlin, Marcos Nogueira; Correa, Deleon Nascimento

2015-04-01

Ammonium nitrate fuel oil (ANFO) is an explosive used in many civil applications. In Brazil, ANFO has unfortunately also been used in criminal attacks, mainly in automated teller machine (ATM) explosions. In this paper, we describe a detailed characterization of the ANFO composition and its two main constituents (diesel and a nitrate explosive) using high resolution and accuracy mass spectrometry performed on an FT-ICR-mass spectrometer with electrospray ionization (ESI(±)-FTMS) in both the positive and negative ion modes. Via ESI(-)-MS, an ion marker for ANFO was characterized. Using a direct and simple ambient desorption/ionization technique, i.e., easy ambient sonic-spray ionization mass spectrometry (EASI-MS), in a simpler, lower accuracy but robust single quadrupole mass spectrometer, the ANFO ion marker was directly detected from the surface of banknotes collected from ATM explosion theft. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Atmospheric pressure ionization-tandem mass spectrometry of the phenicol drug family.

PubMed

Alechaga, Élida; Moyano, Encarnación; Galceran, M Teresa

2013-11-01

In this work, the mass spectrometry behaviour of the veterinary drug family of phenicols, including chloramphenicol (CAP) and its related compounds thiamphenicol (TAP), florfenicol (FF) and FF amine (FFA), was studied. Several atmospheric pressure ionization sources, electrospray (ESI), atmospheric pressure chemical ionization and atmospheric pressure photoionization were compared. In all atmospheric pressure ionization sources, CAP, TAP and FF were ionized in both positive and negative modes; while for the metabolite FFA, only positive ionization was possible. In general, in positive mode, [M + H](+) dominated the mass spectrum for FFA, while the other compounds, CAP, TAP and FF, with lower proton affinity showed intense adducts with species present in the mobile phase. In negative mode, ESI and atmospheric pressure photoionization showed the deprotonated molecule [M-H](-), while atmospheric pressure chemical ionization provided the radical molecular ion by electron capture. All these ions were characterized by tandem mass spectrometry using the combined information obtained by multistage mass spectrometry and high-resolution mass spectrometry in a quadrupole-Orbitrap instrument. In general, the fragmentation occurred via cyclization and losses or fragmentation of the N-(alkyl)acetamide group, and common fragmentation pathways were established for this family of compounds. A new chemical structure for the product ion at m/z 257 for CAP, on the basis of the MS(3) and MS(4) spectra is proposed. Thermally assisted ESI and selected reaction monitoring are proposed for the determination of these compounds by ultra high-performance liquid chromatography coupled to tandem mass spectrometry, achieving instrumental detection limits down to 0.1 pg. Copyright © 2013 John Wiley & Sons, Ltd.

Mass spectrometry for the determination of fission products 135Cs, 137Cs and 90Sr: A review of methodology and applications

NASA Astrophysics Data System (ADS)

Bu, Wenting; Zheng, Jian; Liu, Xuemei; Long, Kaiming; Hu, Sheng; Uchida, Shigeo

2016-05-01

The radioactive fission products 135Cs, 137Cs and 90Sr have been released into the environment by human activities such as nuclear weapon tests, nuclear fuel reprocessing and nuclear power plant accidents. Monitoring of these radionuclides is important for dose assessment. Moreover, the 135Cs/137Cs isotopic ratio can be used as an important long-term fingerprint for radioactive source identification as it varies with weapon, reactor and fuel types. In recent years, mass spectrometry has become a powerful method for the determination of 135Cs, 137Cs and 90Sr in environmental samples. Mass spectrometry is characterized by the high sensitivity and low detection limit and the relatively shorter sample preparation and analysis times compared with radiometric methods. However, the mass spectrometric determination of radiocesium and 90Sr is affected by the peak tailings of the stable nuclides 133Cs and 88Sr, respectively, and the related isobaric and polyatomic interferences. Chemical separation and optimization of the mass spectrometry instrumental setup are strongly needed prior to the mass spectrometry detection. In this paper, we have reviewed the published works about the determination of 135Cs, 137Cs and 90Sr by mass spectrometry. The mass spectrometric techniques we cover are resonance ionization mass spectrometry (RIMS), thermal ionization mass spectrometry (TIMS), accelerator mass spectrometry (AMS) and inductively coupled plasma mass spectrometry (ICP-MS). For each technique, the principles or strategies used for the analysis of these radionuclides are discussed; these included the abundance sensitivity, ways to suppress the interference signals, and the instrumental setup. In particular, the chemical procedures for eliminating the interferences are also summarized. To date, triple quadrupole ICP-MS (ICP-QQQ) showed great ability for the analysis of these radionuclides and the detection limits were as low as 0.01 pg/mL levels. Finally, some investigations on the behaviors of radiocesium and radioactive source identifications are presented with the results of 135Cs/137Cs isotopic ratios measured in various environmental samples.

Detection and Structural Characterization of Nucleophiles Trapped Reactive Metabolites of Limonin Using Liquid Chromatography-Mass Spectrometry

PubMed Central

Deng, Yujie; Fu, Yudong; Xu, Shumin; Wang, Ping; Yang, Nailong; Li, Chengqian

2018-01-01

Limonin (LIM), a furan-containing limonoid, is one of the most abundant components of Dictamnus dasycarpus Turcz. Recent studies demonstrated that LIM has great potential for inhibiting the activity of drug-metabolizing enzymes. However, the mechanisms of LIM-induced enzyme inactivation processes remain unexplored. The main objective of this study was to identify the reactive metabolites of LIM using liquid chromatography-mass spectrometry. Three nucleophiles, glutathione (GSH), N-acetyl cysteine (NAC), and N-acetyl lysine (NAL), were used to trap the reactive metabolites of LIM in in vitro and in vivo models. Two different types of mass spectrometry, a hybrid quadrupole time-of-flight (Q-TOF) mass spectrometry and a LTQ velos Pro ion trap mass spectrometry, were employed to acquire structural information of nucleophile adducts of LIM. In total, six nucleophile adducts of LIM (M1–M6) with their isomers were identified; among them, M1 was a GSH and NAL conjugate of LIM, M2–M4 were glutathione adducts of LIM, M5 was a NAC and NAL conjugate of LIM, and M6 was a NAC adduct of LIM. Additionally, CYP3A4 was found to be the key enzyme responsible for the bioactivation of limonin. This metabolism study largely facilitates the understanding of mechanisms of limonin-induced enzyme inactivation processes. PMID:29850372

High-Throughput Analysis of Sucrose Fatty Acid Esters by Supercritical Fluid Chromatography/Tandem Mass Spectrometry

PubMed Central

Hori, Katsuhito; Tsumura, Kazunobu; Fukusaki, Eiichiro; Bamba, Takeshi

2014-01-01

Supercritical fluid chromatography (SFC) coupled with triple quadrupole mass spectrometry was applied to the profiling of sucrose fatty acid esters (SEs). The SFC conditions (column and modifier gradient) were optimized for the effective separation of SEs. In the column test, a silica gel reversed-phase column was selected. Then, the method was used for the detailed characterization of commercial SEs and the successful analysis of SEs containing different fatty acids. The present method allowed for fast and high-resolution separation of monoesters to tetra-esters within a shorter time (15 min) as compared to the conventional high-performance liquid chromatography. The applicability of our method for the analysis of SEs was thus demonstrated. PMID:26819875

The Assessment of Selectivity in Different Quadrupole-Orbitrap Mass Spectrometry Acquisition Modes

NASA Astrophysics Data System (ADS)

Berendsen, Bjorn J. A.; Wegh, Robin S.; Meijer, Thijs; Nielen, Michel W. F.

2015-02-01

Selectivity of the confirmation of identity in liquid chromatography (tandem) mass spectrometry using Q-Orbitrap instrumentation was assessed using different acquisition modes based on a representative experimental data set constructed from 108 samples, including six different matrix extracts and containing over 100 analytes each. Single stage full scan, all ion fragmentation, and product ion scanning were applied. By generating reconstructed ion chromatograms using unit mass window in targeted MS2, selected reaction monitoring (SRM), regularly applied using triple-quadrupole instruments, was mimicked. This facilitated the comparison of single stage full scan, all ion fragmentation, (mimicked) SRM, and product ion scanning applying a mass window down to 1 ppm. Single factor Analysis of Variance was carried out on the variance (s2) of the mass error to determine which factors and interactions are significant parameters with respect to selectivity. We conclude that selectivity is related to the target compound (mainly the mass defect), the matrix, sample clean-up, concentration, and mass resolution. Selectivity of the different instrumental configurations was quantified by counting the number of interfering peaks observed in the chromatograms. We conclude that precursor ion selection significantly contributes to selectivity: monitoring of a single product ion at high mass accuracy with a 1 Da precursor ion window proved to be equally selective or better to monitoring two transition products in mimicked SRM. In contrast, monitoring a single fragment in all ion fragmentation mode results in significantly lower selectivity versus mimicked SRM. After a thorough inter-laboratory evaluation study, the results of this study can be used for a critical reassessment of the current identification points system and contribute to the next generation of evidence-based and robust performance criteria in residue analysis and sports doping.

Identification of phenolic compounds in red wine extract samples and zebrafish embryos by HPLC-ESI-LTQ-Orbitrap-MS.

PubMed

Vallverdú-Queralt, Anna; Boix, Nuria; Piqué, Ester; Gómez-Catalan, Jesús; Medina-Remon, Alexander; Sasot, Gemma; Mercader-Martí, Mercè; Llobet, Juan M; Lamuela-Raventos, Rosa M

2015-08-15

The zebrafish embryo is a highly interesting biological model with applications in different scientific fields, such as biomedicine, pharmacology and toxicology. In this study, we used liquid chromatography/electrospray ionisation-linear ion trap quadrupole-Orbitrap-mass spectrometry (HPLC/ESI-LTQ-Orbitrap-MS) to identify the polyphenol compounds in a red wine extract and zebrafish embryos. Phenolic compounds and anthocyanin metabolites were determined in zebrafish embryos previously exposed to the red wine extract. Compounds were identified by injection in a high-resolution system (LTQ-Orbitrap) using accurate mass measurements in MS, MS(2) and MS(3) modes. To our knowledge, this research constitutes the first comprehensive identification of phenolic compounds in zebrafish by HPLC coupled to high-resolution mass spectrometry. Copyright © 2015 Elsevier Ltd. All rights reserved.

Detection of polydimethylsiloxanes transferred from silicone-coated parchment paper to baked goods using direct analysis in real time mass spectrometry.

PubMed

Jakob, Andreas; Crawford, Elizabeth A; Gross, Jürgen H

2016-04-01

The non-stick properties of parchment papers are achieved by polydimethylsiloxane (PDMS) coatings. During baking, PDMS can thus be extracted from the silicone-coated parchment into the baked goods. Positive-ion direct analysis in real time (DART) mass spectrometry (MS) is highly efficient for the analysis of PDMS. A DART-SVP source was coupled to a quadrupole-time-of-flight mass spectrometer to detect PDMS on the contact surface of baked goods after use of silicone-coated parchment papers. DART spectra from the bottom surface of baked cookies and pizzas exhibited signals because of PDMS ions of the general formula [(C2H6SiO)n  + NH4 ](+) in the m/z 800-1900 range. Copyright © 2016 John Wiley & Sons, Ltd.

Differentiating Organic and Conventional Sage by Chromatographic and Mass Spectrometry Flow-Injection Fingerprints Combined with Principal Component Analysis

PubMed Central

Gao, Boyan; Lu, Yingjian; Sheng, Yi; Chen, Pei; Yu, Liangli (Lucy)

2013-01-01

High performance liquid chromatography (HPLC) and flow injection electrospray ionization with ion trap mass spectrometry (FIMS) fingerprints combined with the principal component analysis (PCA) were examined for their potential in differentiating commercial organic and conventional sage samples. The individual components in the sage samples were also characterized with an ultra-performance liquid chromatography with a quadrupole-time of flight mass spectrometer (UPLC Q-TOF MS). The results suggested that both HPLC and FIMS fingerprints combined with PCA could differentiate organic and conventional sage samples effectively. FIMS may serve as a quick test capable of distinguishing organic and conventional sages in 1 min, and could potentially be developed for high-throughput applications; whereas HPLC fingerprints could provide more chemical composition information with a longer analytical time. PMID:23464755

Alkyd paints in art: characterization using integrated mass spectrometry.

PubMed

La Nasa, Jacopo; Degano, Ilaria; Modugno, Francesca; Colombini, Maria Perla

2013-10-03

Alkyd resins have been commonly used as binders in artist paints since the 1940s. The characterization of alkyds in samples from artworks can help to solve attribution and dating issues, investigate decay processes, and contribute to the planning of conservation strategies. Being able to assess the components of industrially formulated paint materials and to differentiate between different trademarks and producers is extremely interesting and requires multi-analytical approaches. In this paper we describe the characterization of commercial alkyd paint materials using a multi-analytical approach based on the integration of three different mass spectrometric techniques: gas chromatography-mass spectrometry (GC/MS), high performance liquid chromatography coupled with electrospray ionization mass spectrometry with a tandem quadrupole-time of flight mass spectrometer (HPLC-ESI-Q-ToF), and flow injection analysis (FIA) in the ESI-Q-ToF mass spectrometer. GC/MS was successful in determining the fatty acid and aromatic fractions of the resins after hydrolysis; HPLC-ESI-Q-ToF analysis enabled us to identify the triglycerides (TAGs) and diglycerides (DAGs) profile of each resin, and FIA analysis was used as a rapid method to evaluate the presence of possible additives such as synthetic polymers. Copyright © 2013 Elsevier B.V. All rights reserved.

Molecular resolution and fragmentation of fulvic acid by electrospray ionization/multistage tandem mass spectrometry

USGS Publications Warehouse

Leenheer, J.A.; Rostad, C.E.; Gates, Paul M.; Furlong, E.T.; Ferrer, I.

2001-01-01

Molecular weight distributions of fulvic acid from the Suwannee River, Georgia, were investigated by electrospray ionization/quadrupole mass spectrometry (ESI/QMS), and fragmentation pathways of specific fulvic acid masses were investigated by electrospray ionization/ion trap multistage tandem mass spectrometry (ESI/MST/MS). ESI/QMS studies of the free acid form of low molecular weight poly(carboxylic acid) standards in 75% methanol/25% water mobile phase found that negative ion detection gave the optimum generation of parent ions that can be used for molecular weight determinations. However, experiments with poly(acrylic acid) mixtures and specific high molecular weight standards found multiply charged negative ions that gave a low bias to molecular mass distributions. The number of negative charges on a molecule is dependent on the distance between charges. ESI/MST/MS of model compounds found characteristic water loss from alcohol dehydration and anhydride formation, as well as CO2 loss from decarboxylation, and CO loss from ester structures. Application of these fragmentation pathways to specific masses of fulvic acid isolated and fragmented by ESI/MST/MS is indicative of specific structures that can serve as a basis for future structural confirmation after these hypothesized structures are synthesized.

Gas Chromatography-Tandem Mass Spectrometry of Lignin Pyrolyzates with Dopant-Assisted Atmospheric Pressure Chemical Ionization and Molecular Structure Search with CSI:FingerID

NASA Astrophysics Data System (ADS)

Larson, Evan A.; Hutchinson, Carolyn P.; Lee, Young Jin

2018-06-01

Dopant-assisted atmospheric pressure chemical ionization (dAPCI) is a soft ionization method rarely used for gas chromatography-mass spectrometry (GC-MS). The current study combines GC-dAPCI with tandem mass spectrometry (MS/MS) for analysis of a complex mixture such as lignin pyrolysis analysis. To identify the structures of volatile lignin pyrolysis products, collision-induced dissociation (CID) MS/MS using a quadrupole time-of-flight mass spectrometer (QTOFMS) and pseudo MS/MS through in-source collision-induced dissociation (ISCID) using a single stage TOFMS are utilized. To overcome the lack of MS/MS database, Compound Structure Identification (CSI):FingerID is used to interpret CID spectra and predict best matched structures from PubChem library. With this approach, a total of 59 compounds were positively identified in comparison to only 22 in NIST database search of GC-EI-MS dataset. This study demonstrates the effectiveness of GC-dAPCI-MS/MS to overcome the limitations of traditional GC-EI-MS analysis when EI-MS database is not sufficient. [Figure not available: see fulltext.

Analysis, fate studies and monitoring of the antifungal agent clotrimazole in the aquatic environment.

PubMed

Peschka, Manuela; Roberts, Paul H; Knepper, Thomas P

2007-10-01

The analysis and presence of clotrimazole, an antifungal agent with logK(OW) > 4, was thoroughly studied in the aquatic environment. For that reason analytical methods based on gas chromatography-mass spectrometry and liquid chromatography-tandem mass spectrometry were developed and validated to quantify clotrimazole with limits of quantification down to 5 and 1 ng/L, respectively. Both methods were compared in an intercalibration exercise. The complete mass-spectrometric fragmentation pattern could be elucidated with the aid of quadrupole time of flight mass spectrometry. Since clotrimazole tends to adsorb to laboratory glassware, studies on its adsorption behaviour were made to ensure the appropriate handling of water samples, e.g. pH, storage time, pretreatment of sampling vessels or material of the vials used for final extracts. The phenomena of adsorption to suspended matter were investigated while analysing different waste-water samples. Application of the methods in various investigated wastewater and surface water samples demonstrated that clotrimazole could only be detected in the low nanogram per litre range of anthropogenic influenced unfiltered water samples after acidification to pH 2.

Highly informative multiclass profiling of lipids by ultra-high performance liquid chromatography - Low resolution (quadrupole) mass spectrometry by using electrospray ionization and atmospheric pressure chemical ionization interfaces.

PubMed

Beccaria, Marco; Inferrera, Veronica; Rigano, Francesca; Gorynski, Krzysztof; Purcaro, Giorgia; Pawliszyn, Janusz; Dugo, Paola; Mondello, Luigi

2017-08-04

A simple, fast, and versatile method, using an ultra-high performance liquid chromatography system coupled with a low resolution (single quadrupole) mass spectrometer was optimized to perform multiclass lipid profiling of human plasma. Particular attention was made to develop a method suitable for both electrospray ionization and atmospheric pressure chemical ionization interfaces (sequentially in positive- and negative-ion mode), without any modification of the chromatographic conditions (mobile phase, flow-rate, gradient, etc.). Emphasis was given to the extrapolation of the structural information based on the fragmentation pattern obtained using atmospheric pressure chemical ionization interface, under each different ionization condition, highlighting the complementary information obtained using the electrospray ionization interface, of support for related molecule ions identification. Furthermore, mass spectra of phosphatidylserine and phosphatidylinositol obtained using the atmospheric pressure chemical ionization interface are reported and discussed for the first time. Copyright © 2017 Elsevier B.V. All rights reserved.

Assessment of benzophenone-4 reactivity with free chlorine by liquid chromatography quadrupole time-of-flight mass spectrometry.

PubMed

Negreira, N; Rodríguez, I; Rodil, R; Cela, R

2012-09-19

The stability of the UV filter benzophenone-4 (BP-4) in free chlorine-containing water was investigated, for the first time, by liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QqTOF-MS). High mass accuracy and resolution capabilities of this hybrid mass spectrometer were used for the reliable assignation of empirical formulae and chemical structures of BP-4 derivatives. Time-course profiles of the parent compound and its by-products were simultaneously recorded by direct injection of sample aliquots, after quenching the excess of chlorine, in the LC-QqTOF-MS system. At neutral pHs, in excess of chlorine, BP-4 showed a limited stability fitting a pseudo-first-order degradation kinetics. A noticeable reduction in the half-lives of BP-4 was observed when increasing the sample pH between 6 and 8 units and also in presence of bromide traces. The reaction pathway of this UV filter involved a first electrophilic substitution of hydrogen per chlorine (or bromide) in the phenolic ring, followed by oxidation of the carbonyl moiety to an ester group, which induced a further electrophilic substitution in the same aromatic ring. Above reactions were also noticed when mixing a BP-4 containing personal care product with chlorinated tap water and in chlorinated swimming pool and sewage water, previously spiked with a BP-4 standard. Copyright © 2012 Elsevier B.V. All rights reserved.

Orthogonal Injection Ion Funnel Interface Providing Enhanced Performance for Selected Reaction Monitoring-Triple Quadrupole Mass Spectrometry

PubMed Central

Chen, Tsung-Chi; Fillmore, Thomas L.; Prost, Spencer A.; Moore, Ronald J.; Ibrahim, Yehia M.; Smith, Richard D.

2016-01-01

The electrodynamic ion funnel facilitates efficient focusing and transfer of charged particles in the higher-pressure regions (e.g., ion source interfaces) of mass spectrometers, thus providing increased sensitivity. An “off-axis” ion funnel design has been developed to reduce the source contamination and interferences from, e.g. ESI droplet residue and other poorly focused neutral or charged particles with very high mass-to-charge ratios. In this study, a dual ion funnel interface consisting of an orthogonal higher pressure electrodynamic ion funnel (HPIF) and an ion funnel trap combined with a triple quadrupole mass spectrometer was developed and characterized. An orthogonal ion injection inlet and a repeller plate electrode was used to direct ions to an ion funnel HPIF at a pressure of 9–10 Torr. Key factors for the HPIF performance characterized included the effects of RF amplitude, the DC gradient, and operating pressure. Compared to the triple quadrupole standard interface more than 4-fold improvement in the limit of detection for the direct quantitative MS analysis of low abundance peptides was observed. The sensitivity enhancement in liquid chromatography selected reaction monitoring (LC-SRM) analyses of low-abundance peptides spiked into a highly complex mixture was also compared with that obtained using both a commercial S-lens interface and an in-line dual-ion funnel interface. PMID:26107611

Development of a simple and rapid solid phase microextraction-gas chromatography-triple quadrupole mass spectrometry method for the analysis of dopamine, serotonin and norepinephrine in human urine.

PubMed

Naccarato, Attilio; Gionfriddo, Emanuela; Sindona, Giovanni; Tagarelli, Antonio

2014-01-31

The work aims at developing a simple and rapid method for the quantification of dopamine (DA), serotonin (5-HT) and norepinephrine (NE) in human urine. The urinary levels of these biogenic amines can be correlated with several pathological conditions concerning heart disease, stress, neurological disorders and cancerous tumors. The proposed analytical approach is based on the use of solid phase microextraction (SPME) combined with gas chromatography-triple quadrupole mass spectrometry (GC-QqQ-MS) after a fast derivatization of both aliphatic amino and phenolic moieties by propyl chloroformate. The variables influencing the derivatization reaction were reliably optimized by the multivariate approach of "Experimental design". The optimal conditions were obtained by performing derivatization with 100μL of propyl chloroformate and 100μL of pyridine. The extraction ability of five commercially available SPME fibers was evaluated in univariate mode and the best results were obtained using the polyacrylate fiber. The variables affecting the efficiency of SPME analysis were again optimized by the multivariate approach of "Experimental design" and, in particular, a central composite design (CCD) was applied. The optimal values were extraction in 45min at room temperature, desorption temperature at 300°C, no addition of NaCl. Assay of derivatized analytes was performed by using a gas chromatography-triple quadrupole mass spectrometry (GC-QqQ-MS) system in selected reaction monitoring (SRM) acquisition. An evaluation of all analytical parameters demonstrates that the developed method provides satisfactory results. Indeed, very good linearities were achieved in the tested calibration range with correlation coefficient values of 0.9995, 0.9999 and 0.9997 for DA, 5-HT and NE, respectively. Accuracies and RSDs calculated for between-run and tested at concentrations of 30, 200, and 800μg L(-1) were in the range from 92.8% to 103.0%, and from 0.67 to 4.5%, respectively. Finally, the LOD values obtained can be considered very good (0.587, 0.381 and 1.23μg L(-1) for DA, 5-HT and NE, respectively). Copyright © 2013 Elsevier B.V. All rights reserved.

A solid-phase microextraction-gas chromatographic approach combined with triple quadrupole mass spectrometry for the assay of carbamate pesticides in water samples.

PubMed

Cavaliere, Brunella; Monteleone, Marcello; Naccarato, Attilio; Sindona, Giovanni; Tagarelli, Antonio

2012-09-28

A simple and sensitive method was developed for the quantification of five carbamate pesticides in water samples using solid phase microextraction (SPME) combined with gas chromatography-triple quadrupole mass spectrometry (GC-QqQ-MS). The performance of five SPME fibers was tested in univariate mode whereas the other variables affecting the efficiency of SPME analysis were optimized by the multivariate approach of design of experiment (DoE) and, in particular, a central composite design (CCD) was applied. The optimum working conditions in terms of response values were achieved by performing analysis with polydimethylsiloxane/divinylbenzene (PDMS/DVB) fiber in immersion mode for 45min at room temperature with addition of NaCl (10%). The multivariate chemometric approach was also used to explore the chromatographic behavior of the carbamates and to evaluate the importance of each variable investigated. An overall appraisement of results shows that the factor which gave a statistically significant effect on the response was only the injection temperature. Identification and quantification of carbamates was performed by using a gas chromatography-triple quadrupole mass spectrometry (GC-QqQ-MS) system in multiple reaction monitoring (MRM) acquisition. Since the choice of internal standard represented a crucial step in the development of method to achieve good reproducibility and robustness for the entire analytical protocol, three compounds (2,3,5-trimethacarb, 4-bromo-3,5-dimethylphenyl-n-methylcarbamate (BDMC) and carbaryl-d7) were evaluated as internal standards. Both precision and accuracy of the proposed protocol tested at concentration of 0.08, 5 and 3 μg l⁻¹ offered values ranging from 70.8% and 115.7% (except for carbaryl at 3 μg l⁻¹) and from 1.0% and 9.0% for accuracy and precision, respectively. Moreover, LOD and LOQ values ranging from 0.04 to 1.7 ng l⁻¹ and from 0.64 to 2.9 ng l⁻¹, respectively, can be considered very satisfactory. Copyright © 2012 Elsevier B.V. All rights reserved.

Linear Ion Traps in Space: The Mars Organic Molecule Analyzer (MOMA) Instrument and Beyond

NASA Astrophysics Data System (ADS)

Arevalo, Ricardo; Brinckerhoff, William; Mahaffy, Paul; van Amerom, Friso; Danell, Ryan; Pinnick, Veronica; Li, Xiang; Hovmand, Lars; Getty, Stephanie; Grubisic, Andrej; Goesmann, Fred; Cottin, Hervé

2015-11-01

Historically, quadrupole mass spectrometer (QMS) instruments have been used to explore a wide survey of planetary targets in our solar system, from Venus (Pioneer Venus) to Saturn (Cassini-Huygens). However, linear ion trap (LIT) mass spectrometers have found a niche as smaller, versatile alternatives to traditional quadrupole analyzers.The core astrobiological experiment of ESA’s ExoMars Program is the Mars Organic Molecule Analyzer (MOMA) onboard the ExoMars 2018 rover. The MOMA instrument is centered on a linear (or 2-D) ion trap mass spectrometer. As opposed to 3-D traps, LIT-based instruments accommodate two symmetrical ion injection pathways, enabling two complementary ion sources to be used. In the case of MOMA, these two analytical approaches are laser desorption mass spectrometry (LDMS) at Mars ambient pressures, and traditional gas chromatography mass spectrometry (GCMS). The LIT analyzer employed by MOMA also offers: higher ion capacity compared to a 3-D trap of the same volume; redundant detection subassemblies for extended lifetime; and, a link to heritage QMS designs and assembly logistics. The MOMA engineering test unit (ETU) has demonstrated the detection of organics in the presence of wt.%-levels of perchlorate, effective ion enhancement via stored waveform inverse Fourier transform (SWIFT), and derivation of structural information through tandem mass spectrometry (MS/MS).A more progressive linear ion trap mass spectrometer (LITMS), funded by the NASA ROSES MatISSE Program, is being developed at NASA GSFC and promises to augment the capabilities of the MOMA instrument by way of: an expanded mass range (i.e., 20 - 2000 Da); detection of both positive and negative ions; spatially resolved (<1 mm) characterization of individual rock core layers; and, evolved gas analysis and GCMS with pyrolysis up to 1300° C (enabling breakdown of refractory phases). The Advanced Resolution Organic Molecule Analyzer (AROMA) instrument, being developed through NASA PICASSO and ESA Research and Development Programs, combines a highly capable LIT front end (a la LITMS) with a high-resolution OrbitrapTM (a la CosmOrbitrap) mass analyzer to enable disambiguation of complex molecular signals in organic-rich targets.

Global chemical profiling based quality evaluation approach of rhubarb using ultra performance liquid chromatography with tandem quadrupole time-of-flight mass spectrometry.

PubMed

Zhang, Li; Liu, Haiyu; Qin, Lingling; Zhang, Zhixin; Wang, Qing; Zhang, Qingqing; Lu, Zhiwei; Wei, Shengli; Gao, Xiaoyan; Tu, Pengfei

2015-02-01

A global chemical profiling based quality evaluation approach using ultra performance liquid chromatography with tandem quadrupole time-of-flight mass spectrometry was developed for the quality evaluation of three rhubarb species, including Rheum palmatum L., Rheum tanguticum Maxim. ex Balf., and Rheum officinale Baill. Considering that comprehensive detection of chemical components is crucial for the global profile, a systemic column performance evaluation method was developed. Based on this, a Cortecs column was used to acquire the chemical profile, and Chempattern software was employed to conduct similarity evaluation and hierarchical cluster analysis. The results showed R. tanguticum could be differentiated from R. palmatum and R. officinale at the similarity value 0.65, but R. palmatum and R. officinale could not be distinguished effectively. Therefore, a common pattern based on three rhubarb species was developed to conduct the quality evaluation, and the similarity value 0.50 was set as an appropriate threshold to control the quality of rhubarb. A total of 88 common peaks were identified by their accurate mass and fragmentation, and partially verified by reference standards. Through the verification, the newly developed method could be successfully used for evaluating the holistic quality of rhubarb. It would provide a reference for the quality control of other herbal medicines. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Measurements of natural uranium concentration and isotopic composition with permil-level precision by inductively coupled plasma-quadrupole mass spectrometry

NASA Astrophysics Data System (ADS)

Shen, Chuan-Chou; Lin, Huei-Ting; Chu, Mei-Fei; Yu, Ein-Fen; Wang, Xianfeng; Dorale, Jeffrey A.

2006-09-01

A new analytical technique using inductively coupled plasma-quadrupole mass spectrometry (ICP-QMS) has been developed that produces permil-level precision in the measurement of uranium concentration ([U]) and isotopic composition (δ234U) in natural materials. A 233U-236U double spike method was used to correct for mass fractionation during analysis. To correct for ratio drifting, samples were bracketed by uranium standard measurements. A sensitivity of 6-7 × 108 cps/ppm was generated with a sample solution uptake rate of 30 μL/min. With a measurement time of 15-20 min, standards of 30-ng uranium produced a within-run precision better than 3‰ (±2 R.S.D.) for δ234U and better than 2‰ for [U]. Replicate measurements made on standards show that a between-run reproducibility of 3.5‰ for δ234U and 2‰ for [U] can be achieved. ICP-QMS data of δ234U and [U] in seawater, coral, and speleothem materials are consistent with the data measured by other ICP-MS and TIMS techniques. Advantages of the ICP-QMS method include low cost, easy maintenance, simple instrumental operation, and few sample preparation steps. Sample size requirements are small, such as 10-14 mg of coral material. The results demonstrate that this technique can be applied to natural samples with various matrices.

Analysis and improved characterization of minor antioxidants from leaves of Malus doumeri using a combination of major constituents' knockout with high-performance liquid chromatography-diode array detector-quadrupole time-of-flight tandem mass spectrometry.

PubMed

Zhao, Huading; Hu, Xin; Chen, Xiaoqin; Shi, Shuyun; Jiang, Xinyu; Liang, Xuejuan; Chen, Wei; Zhang, Shuihan

2015-06-12

Due to the complexity of natural products, efficient identification of bioactive compounds, especially for minor compounds, would require a huge effort. Here, we developed an effective strategy based on combining major constituents' knockout with high-performance liquid chromatography-diode array detector-quadrupole time-of-flight tandem mass spectrometry (HPLC-DAD-QTOF-MS/MS) to comprehensively identify minor antioxidants in Malus doumeri, one of the longest known and most used tonic plant in Taiwan. First, five major compounds (I-V) in M. doumeri were knocked out by two-step stepwise high-speed countercurrent chromatography (HSCCC). Second, minor antioxidants were screened by 1,1-diphenyl-2-picrylhydrazyl radical-HPLC (DPPH-HPLC) assay. Third, structures of thirty minor antioxidants, including 11 dihydrochalcones, 4 flavanones, 3 flavonols, 2 flavones, 3 aurones and 7 phenolic acids, were unambiguously or tentatively identified by matching their characteristic UV spectra, accurate mass signals and key diagnostic fragment ions with standards or previously reported compounds. Twenty-six of them, as far as was known, were discovered from M. doumeri for the first time. The results indicated that the proposed method was a useful approach to explore minor bioactive compounds from complex natural products. Copyright © 2015 Elsevier B.V. All rights reserved.

[Determination of six plant growth regulator residues in strawberry by liquid chromatography-quadrupole time of flight mass spectrometry].

PubMed

Liu, Jingjing; Gong, Ping; Zhang, Xiaomei; Wang, Jianhua; Wang, Jingtang

2012-10-01

A novel method was established for the determination of six plant growth regulators (PGRs), 2,4-dichlorophenoxy acetic (2,4-D), 4-chlorophenoxy-acetic acid (CAP), 4-(3-indolyl)-butyric acid (BAA), forchlorfenuron (CPPU), abscisic acid (ABA) and trans-zeatin (ZT) in strawberry using liquid chromatography-quadrupole-time of flight mass spectrometry (LC-Q TOF MS). The Quick, Easy, Cheap, Effective, Rugged and Safe method (QuEChERS) has been validated for the extraction. In this QuEChERS method, the sample was extracted by acetonitrile and cleaned up with C18 adsorbent. The extract was measured directly by LC-Q TOF MS with electrospray ionization in negative mode. The compounds were separated on an Eclipse XDB-C8 column (150 mm x 4.6 mm, 5 microm) with acetonitrile-5 mmol/L ammonium acetate-0. 1% formic acid as mobile phase under gradient elution. The confirmatory analysis was carried out by determining the accurate masses of all compounds and fragment ions upon Target MS/MS. The limits of detection (LODs) were between 1 microg/kg and 5 microg/kg. The linear range was 0.005-1.0 mg/L for each analyte. The recoveries ranged from 87% to 107% with the relative standard deviations (RSDs) less than 10% (n = 6). The method was proved to be simple and accurate.

Confirmation of Pinnatoxins and Spirolides in Shellfish and Passive Samplers from Catalonia (Spain) by Liquid Chromatography Coupled with Triple Quadrupole and High-Resolution Hybrid Tandem Mass Spectrometry

PubMed Central

García-Altares, María; Casanova, Alexis; Bane, Vaishali; Diogène, Jorge; Furey, Ambrose; de la Iglesia, Pablo

2014-01-01

Cyclic imines are lipophilic marine toxins that bioaccumulate in seafood. Their structure comprises a cyclic-imino moiety, responsible for acute neurotoxicity in mice. Cyclic imines have not been linked yet to human poisonings and are not regulated in Europe, although the European Food Safety Authority requires more data to perform a conclusive risk assessment for consumers. This work presents the first detection of pinnatoxin G (PnTX-G) in Spain and 13-desmethyl spirolide C (SPX-1) in shellfish from Catalonia (Spain, NW Mediterranean Sea). Cyclic imines were found at low concentrations (2 to 60 µg/kg) in 13 samples of mussels and oysters (22 samples analyzed). Pinnatoxin G has been also detected in 17 seawater samples (out of 34) using solid phase adsorption toxin tracking devices (0.3 to 0.9 µg/kg-resin). Pinnatoxin G and SPX-1 were confirmed with both low and high resolution (<2 ppm) mass spectrometry by comparison of the response with that from reference standards. For other analogs without reference standards, we applied a strategy combining low resolution MS with a triple quadrupole mass analyzer for a fast and reliable screening, and high resolution MS LTQ Orbitrap® for unambiguous confirmation. The advantages and limitations of using high resolution MS without reference standards were discussed. PMID:24960460

mzStudio: A Dynamic Digital Canvas for User-Driven Interrogation of Mass Spectrometry Data.

PubMed

Ficarro, Scott B; Alexander, William M; Marto, Jarrod A

2017-08-01

Although not yet truly 'comprehensive', modern mass spectrometry-based experiments can generate quantitative data for a meaningful fraction of the human proteome. Importantly for large-scale protein expression analysis, robust data pipelines are in place for identification of un-modified peptide sequences and aggregation of these data to protein-level quantification. However, interoperable software tools that enable scientists to computationally explore and document novel hypotheses for peptide sequence, modification status, or fragmentation behavior are not well-developed. Here, we introduce mzStudio, an open-source Python module built on our multiplierz project. This desktop application provides a highly-interactive graphical user interface (GUI) through which scientists can examine and annotate spectral features, re-search existing PSMs to test different modifications or new spectral matching algorithms, share results with colleagues, integrate other domain-specific software tools, and finally create publication-quality graphics. mzStudio leverages our common application programming interface (mzAPI) for access to native data files from multiple instrument platforms, including ion trap, quadrupole time-of-flight, Orbitrap, matrix-assisted laser desorption ionization, and triple quadrupole mass spectrometers and is compatible with several popular search engines including Mascot, Proteome Discoverer, X!Tandem, and Comet. The mzStudio toolkit enables researchers to create a digital provenance of data analytics and other evidence that support specific peptide sequence assignments.

High mass resolution time of flight mass spectrometer for measuring products in heterogeneous catalysis in highly sensitive microreactors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Andersen, T.; Jensen, R.; Christensen, M. K.

2012-07-15

We demonstrate a combined microreactor and time of flight system for testing and characterization of heterogeneous catalysts with high resolution mass spectrometry and high sensitivity. Catalyst testing is performed in silicon-based microreactors which have high sensitivity and fast thermal response. Gas analysis is performed with a time of flight mass spectrometer with a modified nude Bayard-Alpert ionization gauge as gas ionization source. The mass resolution of the time of flight mass spectrometer using the ion gauge as ionization source is estimated to m/{Delta}m > 2500. The system design is superior to conventional batch and flow reactors with accompanying product detectionmore » by quadrupole mass spectrometry or gas chromatography not only due to the high sensitivity, fast temperature response, high mass resolution, and fast acquisition time of mass spectra but it also allows wide mass range (0-5000 amu in the current configuration). As a demonstration of the system performance we present data from ammonia oxidation on a Pt thin film showing resolved spectra of OH and NH{sub 3}.« less

High mass resolution time of flight mass spectrometer for measuring products in heterogeneous catalysis in highly sensitive microreactors

NASA Astrophysics Data System (ADS)

Andersen, T.; Jensen, R.; Christensen, M. K.; Pedersen, T.; Hansen, O.; Chorkendorff, I.

2012-07-01

We demonstrate a combined microreactor and time of flight system for testing and characterization of heterogeneous catalysts with high resolution mass spectrometry and high sensitivity. Catalyst testing is performed in silicon-based microreactors which have high sensitivity and fast thermal response. Gas analysis is performed with a time of flight mass spectrometer with a modified nude Bayard-Alpert ionization gauge as gas ionization source. The mass resolution of the time of flight mass spectrometer using the ion gauge as ionization source is estimated to m/Δm > 2500. The system design is superior to conventional batch and flow reactors with accompanying product detection by quadrupole mass spectrometry or gas chromatography not only due to the high sensitivity, fast temperature response, high mass resolution, and fast acquisition time of mass spectra but it also allows wide mass range (0-5000 amu in the current configuration). As a demonstration of the system performance we present data from ammonia oxidation on a Pt thin film showing resolved spectra of OH and NH3.

High mass resolution time of flight mass spectrometer for measuring products in heterogeneous catalysis in highly sensitive microreactors.

PubMed

Andersen, T; Jensen, R; Christensen, M K; Pedersen, T; Hansen, O; Chorkendorff, I

2012-07-01

We demonstrate a combined microreactor and time of flight system for testing and characterization of heterogeneous catalysts with high resolution mass spectrometry and high sensitivity. Catalyst testing is performed in silicon-based microreactors which have high sensitivity and fast thermal response. Gas analysis is performed with a time of flight mass spectrometer with a modified nude Bayard-Alpert ionization gauge as gas ionization source. The mass resolution of the time of flight mass spectrometer using the ion gauge as ionization source is estimated to m/Δm > 2500. The system design is superior to conventional batch and flow reactors with accompanying product detection by quadrupole mass spectrometry or gas chromatography not only due to the high sensitivity, fast temperature response, high mass resolution, and fast acquisition time of mass spectra but it also allows wide mass range (0-5000 amu in the current configuration). As a demonstration of the system performance we present data from ammonia oxidation on a Pt thin film showing resolved spectra of OH and NH(3).

Staying Alive: Measuring Intact Viable Microbes with Electrospray Ionization Mass Spectrometry

NASA Astrophysics Data System (ADS)

Forsberg, Erica; Fang, Mingliang; Siuzdak, Gary

2017-01-01

Mass spectrometry has traditionally been the technology of choice for small molecule analysis, making significant inroads into metabolism, clinical diagnostics, and pharmacodynamics since the 1960s. In the mid-1980s, with the discovery of electrospray ionization (ESI) for biomolecule analysis, a new door opened for applications beyond small molecules. Initially, proteins were widely examined, followed by oligonucleotides and other nonvolatile molecules. Then in 1991, three intriguing studies reported using mass spectrometry to examine noncovalent protein complexes, results that have been expanded on for the last 25 years. Those experiments also raised the questions: How soft is ESI, and can it be used to examine even more complex interactions? Our lab addressed these questions with the analyses of viruses, which were initially tested for viability following electrospray ionization and their passage through a quadrupole mass analyzer by placing them on an active medium that would allow them to propagate. This observation has been replicated on multiple different systems, including experiments on an even bigger microbe, a spore. The question of analysis was also addressed in the early 2000s with charge detection mass spectrometry. This unique technology could simultaneously measure mass-to-charge and charge, allowing for the direct determination of the mass of a virus. More recent experiments on spores and enveloped viruses have given us insight into the range of mass spectrometry's capabilities (reaching 100 trillion Da), beginning to answer fundamental questions regarding the complexity of these organisms beyond proteins and genes, and how small molecules are integral to these supramolecular living structures.

Characterization and quantitative analysis of surfactants in textile wastewater by liquid chromatography/quadrupole-time-of-flight mass spectrometry.

PubMed

González, Susana; Petrović, Mira; Radetic, Maja; Jovancic, Petar; Ilic, Vesna; Barceló, Damià

2008-05-01

A method based on the application of ultra-performance liquid chromatography (UPLC) coupled to hybrid quadrupole-time-of-flight mass spectrometry (QqTOF-MS) with an electrospray (ESI) interface has been developed for the screening and confirmation of several anionic and non-ionic surfactants: linear alkylbenzenesulfonates (LAS), alkylsulfate (AS), alkylethersulfate (AES), dihexyl sulfosuccinate (DHSS), alcohol ethoxylates (AEOs), coconut diethanolamide (CDEA), nonylphenol ethoxylates (NPEOs), and their degradation products (nonylphenol carboxylate (NPEC), octylphenol carboxylate (OPEC), 4-nonylphenol (NP), 4-octylphenol (OP) and NPEO sulfate (NPEO-SO4). The developed methodology permits reliable quantification combined with a high accuracy confirmation based on the accurate mass of the (de)protonated molecules in the TOFMS mode. For further confirmation of the identity of the detected compounds the QqTOF mode was used. Accurate masses of product ions obtained by performing collision-induced dissociation (CID) of the (de)protonated molecules of parent compounds were matched with the ions obtained for a standard solution. The method was applied for the quantitative analysis and high accuracy confirmation of surfactants in complex mixtures in effluents from the textile industry. Positive identification of the target compounds was based on accurate mass measurement of the base peak, at least one product ion and the LC retention time of the analyte compared with that of a standard. The most frequently surfactants found in these textile effluents were NPEO and NPEO-SO4 in concentrations ranging from 0.93 to 5.68 mg/L for NPEO and 0.06 to 4.30 mg/L for NPEO-SO4. AEOs were also identified.

Urine testing for designer steroids by liquid chromatography with androgen bioassay detection and electrospray quadrupole time-of-flight mass spectrometry identification.

PubMed

Nielen, Michel W F; Bovee, Toine F H; van Engelen, Marcel C; Rutgers, Paula; Hamers, Astrid R M; van Rhijn, J Hans A; Hoogenboom, L Ron A P

2006-01-15

New anabolic steroids show up occasionally in sports doping and in veterinary control. The discovery of these designer steroids is facilitated by findings of illicit preparations, thus allowing bioactivity testing, structure elucidation using NMR and mass spectrometry, and final incorporation in urine testing. However, as long as these preparations remain undiscovered, new designer steroids are not screened for in routine sports doping or veterinary control urine tests since the established GC/MS and LC/MS/MS methods are set up for the monitoring of a few selected ions or MS/MS transitions of known substances only. In this study, the feasibility of androgen bioactivity testing and mass spectrometric identification is being investigated for trace analysis of designer steroids in urine. Following enzymatic deconjugation and a generic solid-phase extraction, the samples are analyzed by gradient LC with effluent splitting toward two identical 96-well fraction collectors. One well plate is used for androgen bioactivity detection using a novel robust yeast reporter gene bioassay yielding a biogram featuring a 20-s time resolution. The bioactive wells direct the identification efforts to the corresponding well numbers in the duplicate plate. These are subjected to high-resolution LC using a short column packed with 1.7-microm C18 material and coupled with electrospray quadrupole time-of-flight mass spectrometry (LC/QTOFMS) with accurate mass measurement. Element compositions are calculated and used to interrogate electronic substance databases. The feasibility of this approach for doping control is demonstrated via the screening of human urine samples spiked with the designer anabolic steroid tetrahydrogestrinone. Application of the proposed methodology, complementary to the established targeted urine screening for known anabolics, will increase the chance of finding unknown emerging designer steroids, rather then being solely dependent on findings of the illicit preparations themselves.

Inductively coupled plasma mass spectrometry with a twin quadrupole instrument using laser ablation sample introduction and monodisperse dried microparticulate injection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Allen, Lloyd A.

1996-10-17

The focus of this dissertation is the use of a twin quadrupole inductively coupled plasma mass spectrometer (ICP-MS) for the simultaneous detection of two m/z values. The twin quadrupole ICP-MS is used with laser ablation sample introduction in both the steady state (10 Hz) and single pulse modes. Steady state signals are highly correlated and the majority of flicker noise cancels when the ratio is calculated. Using a copper sample, the isotope ratio 63Cu +/ 65Cu + is measured with a relative standard deviation (RSD) of 0.26%. Transient signals for single laser pulses are also obtained. Copper isotope ratio measurementsmore » for several laser pulses are measured with an RSD of 0.85%. Laser ablation (LA) is used with steel samples to assess the ability of the twin quadrupole ICP-MS to eliminate flicker noise of minor components of steel samples. Isotopic and internal standard ratios are measured in the first part of this work. The isotope ratio 52Cr +/ 53Cr + (Cr present at 1.31 %) can be measured with an RSD of 0.06 % to 0.1 %. For internal standard elements, RSDs improve from 1.9 % in the Cr + signal to 0.12% for the ratio of 51V + to 52Cr +. In the second part of this work, one mass spectrometer is scanned while the second channel measures an individual m/z value. When the ratio of these two signals is calculated, the peak shapes in the mass spectrum are improved significantly. Pulses of analyte and matrix ions from individual drops are measured simultaneously using the twin quadrupole ICP-MS with monodisperse dried microparticulate injection (MDMI). At modest Pb concentrations (500 ppm), a shoulder on the leading edge of the Li + signal becomes apparent. Space charge effects are consistent with the disturbances seen.« less

Validation of a gas chromatography-triple quadrupole mass spectrometry method for confirmatory analysis of dioxins and dioxin-like polychlorobiphenyls in feed following new EU Regulation 709/2014.

PubMed

L'Homme, B; Scholl, G; Eppe, G; Focant, J-F

2015-01-09

The European Regulations laying down methods of sampling and analysis for the EU official control of levels of polychlorodibenzo-p-dioxins (PCDDs), polychloro-dibenzofurans (PCDFs), dioxin-like (DL) and non dioxin-like (NDL) PCBs in food and feed have been recently amended by EU Regulation Nos. 589/2014 and 709/2014. A major update is the recognition of gas chromatography (GC) triple quadrupole mass spectrometry (GC-QQQMS/MS) as a confirmatory tool for checking compliance with maximum levels (ML). These revisions have been initiated since this technology now exhibits similar performances to GC (magnetic sector) high resolution mass spectrometry (GC-HRMS). In this paper, we show a fully validated method for PCDD/Fs and DL-PCBs analysis in feed material of plant origin (vegetable oil) using GC-QQQMS/MS following the dedicated EU Regulation 709/2014. We show that individual analytical criteria (selectivity, linearity, quant/qual MRM transitions, accuracy around ML of 1.50ng WHO2005TEQ/kg, within-lab reproducibility, robustness, and background subtraction) meet the strict requirements set by the EU Regulation. We also propose a clear interpretation of instrumental limit of quantitation (iLOQ) as a 'performance-LOQ', defined in a specific way for GC-QQQMS/MS, and method limit of quantitation (mLOQ) as 'real-LOQ' that is used to report bound results. Eventually, the evaluation of measurement uncertainty, following a top-down approach and data produced with our method, demonstrates similar results than with GC-HRMS, thus offering a reliable alternative to the standard method for vegetable oil. Copyright © 2014 Elsevier B.V. All rights reserved.

Analysis of 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX) and its brominated analogues in chlorine-treated water by gas chromatography coupled to triple quadrupole tandem mass spectrometry (GC-QqQ-MS/MS).

PubMed

Planas, Carles; Ventura, Francesc; Caixach, Josep; Martín, Jordi; Boleda, M Rosa; Paraira, Miquel

2015-11-01

A simple, selective and sensitive method for the analysis of the strong mutagen 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX) and its brominated analogues (BMXs) in chlorine-treated water has been developed. The method is based on gas chromatography coupled to triple quadrupole tandem mass spectrometry (GC-QqQ-MS/MS), previous liquid-liquid extraction (LLE) of a smaller sample volume compared to other methods and on-line derivatization with a silylation reactive. GC-QqQ-MS/MS has been raised as an alternative easier to perform than gas chromatography coupled to high resolution mass spectrometry (GC-HRMS) for the analysis of MX and BMXs, and it allows to achieve low LODs (0.3 ng/L for MX and 0.4-0.9 ng/L for BMXs). This technique had not been previously described for the analysis of MX and BMXs. Quality parameters were calculated and real samples related to 3 drinking water treatment plants (DWTPs), tap water and both untreated and chlorinated groundwater were analyzed. Concentrations of 0.3-6.6 ng/L for MX and 1.0-7.3 ng/L for BMXs were detected. Results were discussed according to five of the main factors affecting MX and BMXs formation in chlorine-treated water (organic precursors, influence of bromide ions, evolution of MX and BMXs in the drinking water distribution system, groundwater chlorination and infiltration of water coming from chlorination processes in groundwater). Copyright © 2015 Elsevier B.V. All rights reserved.

Three Minute Method for Amino Acid Analysis by UHPLC and high resolution quadrupole orbitrap mass spectrometry

PubMed Central

Nemkov, Travis; D'Alessandro, Angelo; Hansen, Kirk C.

2015-01-01

Amino acid analysis is a powerful bioanalytical technique for many biomedical research endeavors, including cancer, emergency medicine, nutrition and neuroscience research. In the present study, we present a three minute analytical method for underivatized amino acid analysis that employs ultra-high performance liquid chromatography and high resolution quadrupole orbitrap mass spectrometry. This method has demonstrated linearity (mM to nM range), reproducibility (intra-day<5%, inter-day<20%), sensitivity (low fmol) and selectivity. Here, we illustrate the rapidity and accuracy of the method through comparison with conventional liquid chromatography-mass spectrometry methods. We further demonstrate the robustness and sensitivity of this method on a diverse range of biological matrices. Using this method we were able to selectively discriminate murine pancreatic cancer cells with and without knocked down expression of Hypoxia Inducible Factor 1α; plasma, lymph and bronchioalveolar lavage fluid samples from control versus hemorrhaged rats; and muscle tissue samples harvested from rats subjected to both low fat and high fat diets. Furthermore, we were able to exploit the sensitivity of the method to detect and quantify the release of glutamate from sparsely isolated murine taste buds. Spiked in light or heavy standards (13C6-arginine, 13C6-lysine, 13C515N2-glutamine) or xenometabolites were used to determine coefficient of variations, confirm linearity of relative quantitation in four different matrices, and overcome matrix effects for absolute quantitation. The presented method enables high-throughput analysis of low abundance samples requiring only one percent of the material extracted from 100,000 cells, 10 μl of biological fluid, or 2 mg of muscle tissue. PMID:26058356

Surface-Induced Dissociation of Protein Complexes in a Hybrid Fourier Transform Ion Cyclotron Resonance Mass Spectrometer.

PubMed

Yan, Jing; Zhou, Mowei; Gilbert, Joshua D; Wolff, Jeremy J; Somogyi, Árpád; Pedder, Randall E; Quintyn, Royston S; Morrison, Lindsay J; Easterling, Michael L; Paša-Tolić, Ljiljana; Wysocki, Vicki H

2017-01-03

Mass spectrometry continues to develop as a valuable tool in the analysis of proteins and protein complexes. In protein complex mass spectrometry studies, surface-induced dissociation (SID) has been successfully applied in quadrupole time-of-flight (Q-TOF) instruments. SID provides structural information on noncovalent protein complexes that is complementary to other techniques. However, the mass resolution of Q-TOF instruments can limit the information that can be obtained for protein complexes by SID. Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) provides ultrahigh resolution and ultrahigh mass accuracy measurements. In this study, an SID device was designed and successfully installed in a hybrid FT-ICR instrument in place of the standard gas collision cell. The SID-FT-ICR platform has been tested with several protein complex systems (homooligomers, a heterooligomer, and a protein-ligand complex, ranging from 53 to 85 kDa), and the results are consistent with data previously acquired on Q-TOF platforms, matching predictions from known protein interface information. SID fragments with the same m/z but different charge states are well-resolved based on distinct spacing between adjacent isotope peaks, and the addition of metal cations and ligands can also be isotopically resolved with the ultrahigh mass resolution available in FT-ICR.

Carbohydrate profiling of bacteria by gas chromatography-mass spectrometry and their trace detection in complex matrices by gas chromatography-tandem mass spectrometry.

PubMed

Fox, A

1999-05-28

Bacterial cellular polysaccharides are composed of a variety of sugar monomers. These sugars serve as chemical markers to identify specific species or genera or to determine their physiological status. Some of these markers can also be used for trace detection of bacteria or their constituents in complex clinical or environmental matrices. Analyses are performed, in our hands, employing hydrolysis followed by the alditol acetate derivatization procedure. Substantial improvements have been made to sample preparation including simplification and computer-controlled automation. For characterization of whole cell bacterial hydrolysates, sugars are analyzed by gas chromatography-mass spectrometry (GC-MS). Simple chromatograms are generated using selected ion monitoring (SIM). Using total ion GC-MS, sugars can be readily identified. In more complex clinical and environmental samples, markers for bacteria are present at sufficiently low concentrations that more advanced instrumentation, gas chromatography-tandem mass spectrometry (GC-MS-MS), is preferred for optimal analysis. Using multiple reaction monitoring, MS-MS is used (replacing more conventional SIM) to ignore extraneous chromatographic peaks. Triple quadrupole and ion trap GC-MS-MS instruments have both been used successfully. Absolute chemical identification of sugar markers at trace levels is achieved, using MS-MS, by the product spectrum.

Mass spectrometry analysis of terpene lactones in Ginkgo biloba.

PubMed

Ding, Shujing; Dudley, Ed; Song, Qingbao; Plummer, Sue; Tang, Jiandong; Newton, Russell P; Brenton, A Gareth

2008-01-01

Terpene lactones are a family of compounds with unique chemical structures, first recognised in an extract of Ginkgo biloba. The discovery of terpene lactone derivatives has recently been reported in more and more plant extracts and even food products. In this study, mass spectrometric characteristics of the standard terpene lactones in Ginkgo biloba were comprehensively studied using both an ion trap and a quadrupole time-of-flight (QTOF) mass spectrometer. The mass spectral fragmentation data from both techniques was compared to obtain the mass spectrometric fragmentation pathways of the terpene lactones with high confidence. The data obtained will facilitate the analysis and identification of terpene lactones in future plant research via the fragmentation knowledge reported here.

Determination of gamma-aminobutyric acid in food matrices by isotope dilution hydrophilic interaction chromatography coupled to mass spectrometry.

PubMed

Zazzeroni, Raniero; Homan, Andrew; Thain, Emma

2009-08-01

The estimation of the dietary intake of gamma-aminobutyric acid (GABA) is dependent upon the knowledge of its concentration values in food matrices. To this end, an isotope dilution liquid chromatography-mass spectrometry method has been developed employing the hydrophilic interaction chromatography technique for analyte separation. This approach enabled accurate quantification of GABA in apple, potato, soybeans, and orange juice without the need of a pre- or post-column derivatization reaction. A selective and precise analytical measurement has been obtained with a triple quadrupole mass spectrometer operating in multiple reaction monitoring using the method of standard additions and GABA-d(6) as an internal standard. The concentrations of GABA found in the matrices tested are 7 microg/g of apple, 342 microg/g of potatoes, 211 microg/g of soybeans, and 344 microg/mL of orange juice.

Identification of substances migrating from plastic baby bottles using a combination of low-resolution and high-resolution mass spectrometric analysers coupled to gas and liquid chromatography.

PubMed

Onghena, Matthias; Van Hoeck, Els; Van Loco, Joris; Ibáñez, María; Cherta, Laura; Portolés, Tania; Pitarch, Elena; Hernandéz, Félix; Lemière, Filip; Covaci, Adrian

2015-11-01

This work presents a strategy for elucidation of unknown migrants from plastic food contact materials (baby bottles) using a combination of analytical techniques in an untargeted approach. First, gas chromatography (GC) coupled to mass spectrometry (MS) in electron ionisation mode was used to identify migrants through spectral library matching. When no acceptable match was obtained, a second analysis by GC-(electron ionisation) high resolution mass spectrometry time of flight (TOF) was applied to obtain accurate mass fragmentation spectra and isotopic patterns. Databases were then searched to find a possible elemental composition for the unknown compounds. Finally, a GC hybrid quadrupole-TOF-MS with an atmospheric pressure chemical ionisation source was used to obtain the molecular ion or the protonated molecule. Accurate mass data also provided additional information on the fragmentation behaviour as two acquisition functions with different collision energies were available (MS(E) approach). In the low-energy function, limited fragmentation took place, whereas for the high-energy function, fragmentation was enhanced. For less volatile unknowns, ultra-high pressure liquid chromatography-quadrupole-TOF-MS was additionally applied. Using a home-made database containing common migrating compounds and plastic additives, tentative identification was made for several positive findings based on accurate mass of the (de)protonated molecule, product ion fragments and characteristic isotopic ions. Six illustrative examples are shown to demonstrate the modus operandi and the difficulties encountered during identification. The combination of these techniques was proven to be a powerful tool for the elucidation of unknown migrating compounds from plastic baby bottles. Copyright © 2015 John Wiley & Sons, Ltd.

Determination of sulfonamide antibiotics and metabolites in liver, muscle and kidney samples by pressurized liquid extraction or ultrasound-assisted extraction followed by liquid chromatography-quadrupole linear ion trap-tandem mass spectrometry (HPLC-QqLIT-MS/MS).

PubMed

Hoff, Rodrigo Barcellos; Pizzolato, Tânia Mara; Peralba, Maria do Carmo Ruaro; Díaz-Cruz, M Silvia; Barceló, Damià

2015-03-01

Sulfonamides are widely used in human and veterinary medicine. The presence of sulfonamides residues in food is an issue of great concern. Throughout the present work, a method for the targeted analysis of 16 sulfonamides and metabolites residue in liver of several species has been developed and validated. Extraction and clean-up has been statistically optimized using central composite design experiments. Two extraction methods have been developed, validated and compared: i) pressurized liquid extraction, in which samples were defatted with hexane and subsequently extracted with acetonitrile and ii) ultrasound-assisted extraction with acetonitrile and further liquid-liquid extraction with hexane. Extracts have been analyzed by liquid chromatography-quadrupole linear ion trap-tandem mass spectrometry. Validation procedure has been based on the Commission Decision 2002/657/EC and included the assessment of parameters such as decision limit (CCα), detection capability (CCβ), sensitivity, selectivity, accuracy and precision. Method׳s performance has been satisfactory, with CCα values within the range of 111.2-161.4 µg kg(-1), limits of detection of 10 µg kg(-1) and accuracy values around 100% for all compounds. Copyright © 2014 Elsevier B.V. All rights reserved.

A target and nontarget strategy for identification or characterization of the chemical ingredients in Chinese herb preparation Shuang-Huang-Lian oral liquid by ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry.

PubMed

Zhang, Feng-Xiang; Li, Min; Yao, Zhi-Hong; Li, Chang; Qiao, Li-Rui; Shen, Xiu-Yu; Yu, Kate; Dai, Yi; Yao, Xin-Sheng

2018-03-01

A target and nontarget strategy based on in-house chemical components library was developed for rapid and comprehensive analysis of complicated components from traditional Chinese medicine preparation Shuang-Huang-Lian oral liquid. The sample was analyzed by ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry using generic acquisition parameters. Automated detection and data filtering were performed on the UNIFI™ software and the detected peaks were evaluated against an in-house library. As a result, a total of 170 chemical components (110 target compounds and 60 nontarget ones) were identified or tentatively characterized, including 54 flavonoids, 30 phenylethanoid glycosides, 16 iridoid glycosides, 14 lignans, 32 organic acids, 19 triterpenoid saponins and five other types of compounds. Among them, 44 compounds were further confirmed by comparison with reference standards. It was demonstrated that this systematical approach could be successfully applied for rapid identification of multiple compounds in traditional Chinese medicine and its preparations. Furthermore, this work established the foundation for the further investigation on the metabolic fates of multiple ingredients in Shuang-Huang-Lian oral liquid. Copyright © 2017 John Wiley & Sons, Ltd.

Fast separation of triterpenoid saponins using supercritical fluid chromatography coupled with single quadrupole mass spectrometry.

PubMed

Huang, Yang; Zhang, Tingting; Zhou, Haibo; Feng, Ying; Fan, Chunlin; Chen, Weijia; Crommen, Jacques; Jiang, Zhengjin

2016-03-20

Triterpenoid saponins (TSs) are the most important components of some traditional Chinese medicines (TCMs) and have exhibited valuable pharmacological properties. In this study, a rapid and efficient method was developed for the separation of kudinosides, stauntosides and ginsenosides using supercritical fluid chromatography coupled with single quadrupole mass spectrometry (SFC-MS). The separation conditions for the selected TSs were carefully optimized after the initial screening of eight stationary phases. The best compromise for all compounds in terms of chromatographic performance and MS sensitivity was obtained when water (5-10%) and formic acid (0.05%) were added to the supercritical carbon dioxide/MeOH mobile phase. Beside the composition of the mobile phase, the nature of the make-up solvent for interfacing SFC with MS was also evaluated. Compared to reversed phase liquid chromatography, the SFC approach showed higher resolution and shorter running time. The developed SFC-MS methods were successfully applied to the separation and identification of TSs present in Ilex latifolia Thunb., Panax quinquefolius L. and Panax ginseng C.A. Meyer. These results suggest that this SFC-MS approach could be employed as a useful tool for the quality assessment of natural products containing TSs as active components. Copyright © 2015 Elsevier B.V. All rights reserved.

Metabonomics study on the hot syndrome of traditional Chinese medicine by rapid resolution liquid chromatography combined with quadrupole time-of-flight tandem mass spectrometry.

PubMed

Wang, Yang; Ma, Li; Sun, Yi; Yang, Liman; Yue, Hao; Liu, Shuying

2014-07-01

The hot syndrome refers to any feverish conditions during a pathological development, a sub-health phenomenon, and is a potential risk for human health. The metabonomics study on the hot syndrome may provide insight into understanding of its pathology and play a role in the prevention and treatment of its related diseases. In this paper, the rats were dosed with the hot syndrome prescription, ginseng and water. The corresponding urine samples were identified by rapid resolution liquid chromatography combined with quadrupole time-of-flight tandem mass spectrometry. More than 1,000 metabolic compounds from different urine samples could be further differentiated by principal component analysis. As a result, the rat body temperature and weight were recognized as the hot syndrome related factors. Some specific metabolites have been discovered as a pattern of the potential biomarkers for the hot syndrome. The results showed that ginseng cannot cause the hot syndrome in a reasonable dose, but the hot syndrome prescription can. It is suggested that ginseng cannot be used only as a tradition Chinese medicine but also as a nutrient. The work showed metabonomics method is a valuable tool in studying mechanism of the hot syndrome.

Determination of perchlorate from tea leaves using quaternary ammonium modified magnetic carboxyl-carbon nanotubes followed by liquid chromatography-tandem quadrupole mass spectrometry.

PubMed

Zhao, Yong-Gang; Zhang, Yun; Wang, Feng-Lian; Zhou, Jian; Zhao, Qi-Ming; Zeng, Xiu-Qiong; Hu, Mei-Qin; Jin, Mi-Cong; Zhu, Yan

2018-08-01

The novel quaternary ammonium modified magnetic carboxyl-carbon nanotubes (QA-Mag-CCNTs) have been synthesised and characterized. QA-Mag-CCNTs were applied in magnetic dispersive solid phase extraction (Mag-dSPE) for preconcentration of perchlorate from tea leaves prior to liquid chromatography-tandem quadrupole mass spectrometry (LC-MS/MS) analysis. The Mag-dSPE procedure for preconcentration of perchlorate succeed in overcoming the flaw (containing target analyte randomly) of commercially available SPE cartridge. Under optimal conditions, the results showed higher extraction efficiency of QA-Mag-CCNTs, with recoveries between 85.2% and 107%. And the satisfactory precision with inter-day and intra-day RSD values were lower than 8.0%. Furthermore, QA-Mag-CCNTs were evaluated for reuse up to 20 times. The limit of quantification (LOQ) for perchlorate was 8.21 ng kg -1 . The developed method was successfully applied in tea leaves for food-safety risk monitoring in Zhejiang province, China. The results showed the concentrations of perchlorate in 229 out of 240 collected samples were in the range of 0.082-988 μg kg -1 . It was confirmed that QA-Mag-CCNTs were highly effective materials used for preconcentration of perchlorate. Copyright © 2018 Elsevier B.V. All rights reserved.

Application of High-Performance Liquid Chromatography Coupled with Linear Ion Trap Quadrupole Orbitrap Mass Spectrometry for Qualitative and Quantitative Assessment of Shejin-Liyan Granule Supplements.

PubMed

Gu, Jifeng; Wu, Weijun; Huang, Mengwei; Long, Fen; Liu, Xinhua; Zhu, Yizhun

2018-04-11

A method for high-performance liquid chromatography coupled with linear ion trap quadrupole Orbitrap high-resolution mass spectrometry (HPLC-LTQ-Orbitrap MS) was developed and validated for the qualitative and quantitative assessment of Shejin-liyan Granule. According to the fragmentation mechanism and high-resolution MS data, 54 compounds, including fourteen isoflavones, eleven ligands, eight flavonoids, six physalins, six organic acids, four triterpenoid saponins, two xanthones, two alkaloids, and one licorice coumarin, were identified or tentatively characterized. In addition, ten of the representative compounds (matrine, galuteolin, tectoridin, iridin, arctiin, tectorigenin, glycyrrhizic acid, irigenin, arctigenin, and irisflorentin) were quantified using the validated HPLC-LTQ-Orbitrap MS method. The method validation showed a good linearity with coefficients of determination (r²) above 0.9914 for all analytes. The accuracy of the intra- and inter-day variation of the investigated compounds was 95.0-105.0%, and the precision values were less than 4.89%. The mean recoveries and reproducibilities of each analyte were 95.1-104.8%, with relative standard deviations below 4.91%. The method successfully quantified the ten compounds in Shejin-liyan Granule, and the results show that the method is accurate, sensitive, and reliable.

Metabolomic study of corticosterone-induced cytotoxicity in PC12 cells by ultra performance liquid chromatography-quadrupole/time-of-flight mass spectrometry.

PubMed

Zhang, Hongye; Zheng, Hua; Zhao, Gan; Tang, Chaoling; Lu, Shiyin; Cheng, Bang; Wu, Fang; Wei, Jinbin; Liang, Yonghong; Ruan, Junxiang; Song, Hui; Su, Zhiheng

2016-03-01

Glucocorticoids (GCs) have been proved to be an important pathogenic factor of some neuropsychiatric disorders. Usually, a classical injury model based on corticosterone-induced cytotoxicity of differentiated rat pheochromocytoma (PC12) cells was used to stimulate the state of GC damage of hippocampal neurons and investigate its potential mechanisms involved. However, up to now, the mechanism of corticosterone-induced cytotoxicity in PC12 cells was still looking forward to further elucidation. In this work, the metabolomic study of the biochemical changes caused by corticosterone-induced cytotoxicity in differentiated PC12 cells with different corticosterone concentrations was performed for the first time, using the ultra performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q/TOF MS). Partial least squares-discriminate analysis (PLS-DA) indicated that metabolic profiles of different corticosterone treatment groups deviated from the control group. A total of fifteen metabolites were characterized as potential biomarkers involved in corticosterone-induced cytotoxicity, which were corresponding to the dysfunctions of five pathways including glycerophospholipid metabolism, sphingolipid metabolism, oxidation of fatty acids, glycerolipid metabolism and sterol lipid metabolism. This study indicated that the rapid and holistic cell metabolomics approach might be a powerful tool to further study the pathogenesis mechanism of corticosterone-induced cytotoxicity in PC12 cells.

Piriformospora indica Stimulates Root Metabolism of Arabidopsis thaliana.

PubMed

Strehmel, Nadine; Mönchgesang, Susann; Herklotz, Siska; Krüger, Sylvia; Ziegler, Jörg; Scheel, Dierk

2016-07-08

Piriformospora indica is a root-colonizing fungus, which interacts with a variety of plants including Arabidopsis thaliana. This interaction has been considered as mutualistic leading to growth promotion of the host. So far, only indolic glucosinolates and phytohormones have been identified as key players. In a comprehensive non-targeted metabolite profiling study, we analyzed Arabidopsis thaliana's roots, root exudates, and leaves of inoculated and non-inoculated plants by ultra performance liquid chromatography/electrospray ionization quadrupole-time-of-flight mass spectrometry (UPLC/(ESI)-QTOFMS) and gas chromatography/electron ionization quadrupole mass spectrometry (GC/EI-QMS), and identified further biomarkers. Among them, the concentration of nucleosides, dipeptides, oligolignols, and glucosinolate degradation products was affected in the exudates. In the root profiles, nearly all metabolite levels increased upon co-cultivation, like carbohydrates, organic acids, amino acids, glucosinolates, oligolignols, and flavonoids. In the leaf profiles, we detected by far less significant changes. We only observed an increased concentration of organic acids, carbohydrates, ascorbate, glucosinolates and hydroxycinnamic acids, and a decreased concentration of nitrogen-rich amino acids in inoculated plants. These findings contribute to the understanding of symbiotic interactions between plant roots and fungi of the order of Sebacinales and are a valid source for follow-up mechanistic studies, because these symbioses are particular and clearly different from interactions of roots with mycorrhizal fungi or dark septate endophytes.

Applicability of Gas Chromatography (GC) Coupled to Triple-Quadrupole (QqQ) Tandem Mass Spectrometry (MS/MS) for Polybrominated Diphenyl Ether (PBDE) and Emerging Brominated Flame Retardant (BFR) Determinations in Functional Foods Enriched in Omega-3.

PubMed

García-Bermejo, Ángel; Mohr, Susana; Herrero, Laura; González, María-José; Gómara, Belén

2016-09-28

This paper reports on the optimization, characterization, and applicability of gas chromatography coupled to triple-quadrupole tandem mass spectrometry (GC-QqQ(MS/MS)) for the determination of 14 polybrominated diphenylethers (PBDEs) and 2 emerging brominated flame retardants, 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE) and decabromodiphenylethane (DBDPE), in functional food samples. The method showed satisfactory precision and linearity with instrumental limits of detection (iLODs) ranging from 0.12 to 7.1 pg, for tri- to octa-BDEs and BTBPE, and equal to 51 and 20 pg for BDE-209 and DBDPE, respectively. The highest ΣBFR concentrations were found in fish oil supplements (924 pg/g fresh weight, fw), followed by biscuits (90 pg/g fw), vegetable oil supplements (46 pg/g fw), chicken eggs (45 pg/g fw), cow's milk (7.7 pg/g fw), and soy products (1.6 pg/g fw). BDE-47, BDE-99, and DBDPE were the most abundant compounds. Foodstuffs enriched with omega-3 presented concentrations similar to or even lower than those of conventional foods commercialized in Spain since 2000.

Metabolic profiles of physalin A in rats using ultra-high performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry.

PubMed

Feng, Xinchi; Liu, Hongxia; Chai, Liwei; Ding, Liqin; Pan, Guixiang; Qiu, Feng

2017-03-01

Physalin A, one of the major active components isolated from the calyces of Physalis alkekengi var. franchetii is considered to be a promising natural product due to its anti-inflammatory and excellent antitumor activities. Until now, only one paper is available from our group concerning identification of two sulfonate metabolites from rat feces after physalin A treatment. All the other researches related to physalin A were focused on its extraction, separation and biological activities. In this research, a rapid and reliable ultra-high-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC/Q-TOF-MS/MS) method was developed and employed for the comprehensive study of the metabolism of physalin A in vivo for the first time. A total of 24 proposed metabolites were identified in plasma, bile, urine and feces of rats after oral administration of physalin A. The results indicated that sulfonation, reduction and hydroxylation were the major metabolic pathways of physalin A in vivo. Furthermore, this research provides scientific and reliable support for full understanding of the metabolism of physalin A and the results could help to elucidate the safety and efficacy of physalin A, as well as other physalins. Copyright © 2017 Elsevier B.V. All rights reserved.

A not-stop-flow online normal-/reversed-phase two-dimensional liquid chromatography-quadrupole time-of-flight mass spectrometry method for comprehensive lipid profiling of human plasma from atherosclerosis patients.

PubMed

Li, Min; Tong, Xunliang; Lv, Pu; Feng, Baosheng; Yang, Li; Wu, Zheng; Cui, Xinge; Bai, Yu; Huang, Yining; Liu, Huwei

2014-11-03

A not-stop-flow online two-dimensional (2D) liquid chromatography (LC) method was developed for comprehensive lipid profiling by coupling normal- and reversed-phase LC with quadrupole time-of-flight mass spectrometry (QToF-MS), which was then applied to separate and identify the lipid species in plasma, making its merits in quality and quantity of the detection of lipids. Total 540 endogenous lipid species from 17 classes were determined in human plasma, and the differences in lipid metabolism products in human plasma between atherosclerosis patients and control subjects were explored in detail. The limit of detections (LODs) of 19 validation standards could all reach ng/mL magnitude, and the RSDs of peak area and retention time ranged 0.4-8.0% and 0.010-0.47%, respectively. In addition, a pair of isomers, galactosylceramides (GalC) and glucosylceramides (GluC), was successfully separated, showing that only the levels of GalC in atherosclerosis patients were significantly increasing, rather than GluC, compared with the controls (controls vs. patients: the ratio was 1.5-2.8-fold increasing). It would be helpful to the further research of the atherosclerosis. Copyright © 2014 Elsevier B.V. All rights reserved.

Technical developments for an upgrade of the LEBIT Penning trap mass spectrometry facility for rare isotopes

NASA Astrophysics Data System (ADS)

Redshaw, M.; Barquest, B. R.; Bollen, G.; Bustabad, S. E.; Campbell, C. M.; Ferrer, R.; Gehring, A.; Kwiatkowski, A. A.; Lincoln, D. L.; Morrissey, D. J.; Pang, G. K.; Ringle, R.; Schwarz, S.

2011-07-01

The LEBIT (Low Energy Beam and Ion Trap) facility is the only Penning trap mass spectrometry (PTMS) facility to utilize rare isotopes produced via fast-beam fragmentation. This technique allows access to practically all elements lighter than uranium, and in particular enables the production of isotopes that are not available or that are difficult to obtain at isotope separation on-line facilities. The preparation of the high-energy rare-isotope beam produced by projectile fragmentation for low-energy PTMS experiments is achieved by gas stopping to slow down and thermalize the fast-beam ions, along with an rf quadrupole cooler and buncher and rf quadrupole ion guides to deliver the beam to the Penning trap. During its first phase of operation LEBIT has been very successful, and new developments are now underway to access rare isotopes even farther from stability, which requires dealing with extremely short lifetimes and low production rates. These developments aim at increasing delivery efficiency, minimizing delivery and measurement time, and maximizing use of available beam time. They include an upgrade to the gas-stopping station, active magnetic field monitoring and stabilization by employing a miniature Penning trap as a magnetometer, the use of stored waveform inverse Fourier transform (SWIFT) to most effectively remove unwanted ions, and charge breeding.

Metabolite characterization of a novel anti-cancer agent, icotinib, in humans through liquid chromatography/quadrupole time-of-flight tandem mass spectrometry.

PubMed

Liu, Dongyang; Jiang, Ji; Zhang, Li; Tan, Fenlai; Wang, Yingxiang; Hu, Pei

2011-08-15

Icotinib is a novel anti-cancer drug that has shown promising clinical efficacy and safety in patients with non-small-cell lung cancer (NSCLC). At this time, the metabolic fate of icotinib in humans is unknown. In the present study, a liquid chromatography/quadrupole time-of-flight tandem mass spectrometry (LC/Q-TOF MS) method was established to characterize metabolites of icotinib in human plasma, urine and feces. In addition, nuclear magnetic resonance (NMR) detection was utilized to determine the connection between side-chain and quinazoline groups for some complex metabolites. In total, 29 human metabolites (21 isomer metabolites) were characterized, of which 23 metabolites are novel compared to the metabolites in rats. This metabolic study revealed that icotinib was extensively metabolized at the 12-crown-4 ether moiety (ring-opening and further oxidation), carbon 15 (hydroxylation) and an acetylene moiety (oxidation) to yield 19 oxidized metabolites and to further form 10 conjugates with sulfate acid or glucuronic acid. To our knowledge, this is the first report of the human metabolic profile of icotinib. Study results indicated that significant attention should be paid to the metabolic profiles of NSCLC patients during the development of icotinib. Copyright © 2011 John Wiley & Sons, Ltd.

Application of dispersive solid-phase extraction and ultra-fast liquid chromatography-tandem quadrupole mass spectrometry in food additive residue analysis of red wine.

PubMed

Chen, Xiao-Hong; Zhao, Yong-Gang; Shen, Hao-Yu; Jin, Mi-Cong

2012-11-09

A novel and effective dispersive solid-phase extraction (dSPE) procedure with rapid magnetic separation using ethylenediamine-functionalized magnetic polymer as an adsorbent was developed. The new procedure had excellent clean-up ability for the selective removal of the matrix in red wine. An accurate, simple, and rapid analytical method using ultra-fast liquid chromatography-tandem quadrupole mass spectrometry (UFLC-MS/MS) for the simultaneous determination of nine food additives (i.e., acesulfame, saccharin, sodium cyclamate, aspartame, benzoic acid, sorbic acid, stevioside, dehydroacetic acid, and neotame) in red wine was also used and validated. Recoveries ranging from 78.5% to 99.2% with relative standard deviations ranging from 0.46% to 6.3% were obtained using the new method. All target compounds showed good linearities in the tested range with correlation coefficients (r) higher than 0.9993. The limits of quantification for the nine food additives were between 0.10 μg/L and 50.0 μg/L. The proposed dSPE-UFLC-MS/MS method was successfully applied in the food-safety risk monitoring of real red wine in Zhejiang Province, China. Crown Copyright © 2012. Published by Elsevier B.V. All rights reserved.

Liquid chromatography tandem mass spectrometry determination of chemical markers and principal component analysis of Vitex agnus-castus L. fruits (Verbenaceae) and derived food supplements.

PubMed

Mari, Angela; Montoro, Paola; Pizza, Cosimo; Piacente, Sonia

2012-11-01

A validated analytical method for the quantitative determination of seven chemical markers occurring in a hydroalcoholic extract of Vitex agnus-castus fruits by liquid chromatography electrospray triple quadrupole tandem mass spectrometry (LC/ESI/(QqQ)MSMS) is reported. To carry out a comparative study, five commercial food supplements corresponding to hydroalcoholic extracts of V. agnus-castus fruits were analysed under the same chromatographic conditions of the crude extract. Principal component analysis (PCA), based only on the variation of the amount of the seven chemical markers, was applied in order to find similarities between the hydroalcoholic extract and the food supplements. A second PCA analysis was carried out considering the whole spectroscopic data deriving from liquid chromatography electrospray linear ion trap mass spectrometry (LC/ESI/(LIT)MS) analysis. High similarity between the two PCA was observed, showing the possibility to select one of these two approaches for future applications in the field of comparative analysis of food supplements and quality control procedures. Copyright © 2012 Elsevier B.V. All rights reserved.

Characterization of polyoxyethylene tallow amine surfactants in technical mixtures and glyphosate formulations using ultra-high performance liquid chromatography and triple quadrupole mass spectrometry

USGS Publications Warehouse

Tush, Daniel; Loftin, Keith A.; Meyer, Michael T.

2013-01-01

Little is known about the occurrence, fate, and effects of the ancillary additives in pesticide formulations. Polyoxyethylene tallow amine (POEA) is a non-ionic surfactant used in many glyphosate formulations, a widely applied herbicide both in agricultural and urban environments. POEA has not been previously well characterized, but has been shown to be toxic to various aquatic organisms. Characterization of technical mixtures using ultra-high performance liquid chromatography (UHPLC) and mass spectrometry shows POEA is a complex combination of homologs of different aliphatic moieties and ranges of ethoxylate units. Tandem mass spectrometry experiments indicate that POEA homologs generate no product ions readily suitable for quantitative analysis due to poor sensitivity. A comparison of multiple high performance liquid chromatography (HPLC) and UHPLC analytical columns indicates that the stationary phase is more important in column selection than other parameters for the separation of POEA. Analysis of several agricultural and household glyphosate formulations confirms that POEA is a common ingredient but ethoxylate distributions among formulations vary.

A new method for differentiating adducts of common drinking water DBPs from higher molecular weight DBPs in electrospray ionization-mass spectrometry analysis.

PubMed

Zhai, Hongyan; Zhang, Xiangru

2009-05-01

With the presence of bromide in source waters, numerous brominated disinfection byproducts (DBPs) are formed during chlorination. Many of them are polar/highly polar DBPs and thus hard to be detected by gas chromatography mass spectrometry. Electrospray ionization triple quadrupole mass spectrometry (ESI-MS/MS) is reported to be an effective method in finding polar brominated DBPs by setting precursor ion scans of m/z 79 and 81. But as a soft ionization technique, ESI could form adducts of common DBPs, which may complicate ESI-MS/MS spectra and hinder the efforts in finding new brominated DBPs. In this paper, a new method was developed for differentiating adducts of common DBPs from higher molecular weight DBPs. This method was based on the ESI-MS/MS precursor ion scans of the fragments that correspond to the molecular ions of common DBPs. Adducts of common DBPs were selectively detected in the ESI-MS/MS spectra of a simulated drinking water sample. Moreover, the structures of several new brominated DBPs in the sample were tentatively proposed.

40Ar/36Ar geochronology on a quadrupole mass spectrometer: Where are we going?

NASA Astrophysics Data System (ADS)

Schneider, B.; Wijbrans, J. R.; Kuiper, K. F.; Fenton, C. R.; Williams, A. J.

2009-04-01

40Ar/39Ar analysis has passed many milestones since its first application (Wänke & König, 1959). From the early all-glass Reynolds-type vacuum system to today's high quality, bakeable all-metal piping and valve systems, the evolution of ultra high vacuum systems has been considerable. Extraction systems have faced similar changes over time. Early furnaces made partially of glass were later replaced by full metal constructs containing a high temperature resistant molybdenum alloy tube and heating mechanism, sometimes contained within an insulating secondary vacuum chamber. Laser extraction techniques further refined the approach allowing very small samples or sample parts to be analyzed. The principal type of mass spectrometer used for 40Ar/36Ar geochronology is the magnetic sector instrument, which has the resolution and sensitivity necessary for measuring argon isotopes and achieving high precision over a large age range. We present 40Ar/39Ar data from basalt samples collected from a number of different locations, all obtained using the Hiden HAL Series 1000 quadrupole mass spectrometer at Vrije University, Amsterdam. We show that quadrupole technology is not only a viable option in K-Ar geochronology (Rouchon et al., 2008) but also in 40Ar/39Ar geochronology. The data was obtained from groundmass hand-picked from 200-500 um size fractions. Sample amounts of 200 to 500 mg were used for incremental heating experiments. The quality of the data is demonstrated by convergence of plateau and isochron ages, replicate analyses and by comparison to results of independent studies. Sample ages range from 40 ka to 400 ka, demonstrating the potential of quadrupole instruments for dating even very young rocks using the 40Ar/39Ar incremental heating technique. Rouchon, V., Lefevre, J.-C., Quidelleur, X., Guerin, G., Gillot, P.-Y. (2008): Nonspiked 40Ar and 36Ar quantification using a quadrupole mass spectrometer: A potential for K-Ar geochronology. International Journal of Mass Spectrometry 270, 52-61. Wänke H., König H. (1959): Eine neue Methode zur Kalium-Argon-Altersbestimmung und ihre Anwendung auf Steinmeteorite. Z. Naturforschung, 14a, 860 - 866.

Metabolic characterization of (±)-praeruptorin A in vitro and in vivo by high performance liquid chromatography coupled with hybrid triple quadrupole-linear ion trap mass spectrometry and time-of-flight mass spectrometry.

PubMed

Song, Yue-Lin; Jing, Wang-Hui; Yan, Ru; Wang, Yi-Tao

2014-03-01

(±)-Praeruptorin A (PA) is the major bioactive component in Peucedani Radix (Chinese name: Qian-hu), and exhibits dramatically anti-hypertensive effect typically through acting as a calcium channel blocker. The current study aims on the characterization of the metabolic profiles of PA in vitro and in vivo using high performance liquid chromatography (HPLC) coupled with hybrid triple quadrupole-linear ion trap mass spectrometry (Q-trap-MS) and time-of-flight mass spectrometry (TOF-MS). A total of 12 phase I metabolites (M1-12) in rat liver microsomes (RLMs), 9 phase I metabolites (M1-3, M5-6 and M9-12) in human liver microsomes (HLMs), 2 hydrolyzed products in rat plasma (M11 and M12), none metabolite in human plasma, none metabolite in rat intestinal bacteria, 7 metabolites (M1, M4-7, M13 and M15) in PA-treated rat urine and 6 metabolites (M1, M4-7 and M15) in PA-treated feces were detected and tentatively identified using predictive multiple reaction monitoring-information dependent acquisition-enhanced product ion (predictive MRM-IDA-EPI) mode in combination with enhanced mass spectrum-information dependent acquisition-enhanced product ion (EMS-IDA-EPI) mode in the mass spectrometer domain, respectively, while TOF-MS was adopted to confirm the identification. Further, 2 glucuronidated metabolites (M13-14) in RLMs and none metabolite in HLMs of cis-khellactone (CKL), which was the main actual form of PA in vivo, were generated, while its sulfated product was not observed in either rat liver S9 fractions (RS9) or human liver S9 fractions (HS9). Oxidation, hydrolysis, intra-molecular acyl migration and glucuronidation were demonstrated to be the predominant metabolic types for PA in vitro and in vivo. Judging from the decrement of peak areas, PA was metabolized quickly in both RLMs and HLMs, indicating extensively hepatic first-pass elimination. Taken together, the metabolic fates of (±)-praeruptorin A in vitro and in vivo were elucidated in current study, and Q-trap-MS coupled with LightSight™ software can be adopted as a useful tool for quick detection and identification of metabolites in complex biological matrices. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

Solid Sampling with a Diode Laser for Portable Ambient Mass Spectrometry

PubMed Central

2017-01-01

A hand-held diode laser is implemented for solid sampling in portable ambient mass spectrometry (MS). Specifically, a pseudocontinuous wave battery-powered surgical laser diode is employed for portable laser diode thermal desorption (LDTD) at 940 nm and compared with nanosecond pulsed laser ablation at 2940 nm. Postionization is achieved in both cases using atmospheric pressure photoionization (APPI). The laser ablation atmospheric pressure photoionization (LAAPPI) and LDTD-APPI mass spectra of sage leaves (Salvia officinalis) using a field-deployable quadrupole ion trap MS display many similar ion peaks, as do the mass spectra of membrane grown biofilms of Pseudomonas aeruginosa. These results indicate that LDTD-APPI method should be useful for in-field sampling of plant and microbial communities, for example, by portable ambient MS. The feasibility of many portable MS applications is facilitated by the availability of relatively low cost, portable, battery-powered diode lasers. LDTD could also be coupled with plasma- or electrospray-based ionization for the analysis of a variety of solid samples. PMID:28632988

Solid Sampling with a Diode Laser for Portable Ambient Mass Spectrometry.

PubMed

Yung, Yeni P; Wickramasinghe, Raveendra; Vaikkinen, Anu; Kauppila, Tiina J; Veryovkin, Igor V; Hanley, Luke

2017-07-18

A hand-held diode laser is implemented for solid sampling in portable ambient mass spectrometry (MS). Specifically, a pseudocontinuous wave battery-powered surgical laser diode is employed for portable laser diode thermal desorption (LDTD) at 940 nm and compared with nanosecond pulsed laser ablation at 2940 nm. Postionization is achieved in both cases using atmospheric pressure photoionization (APPI). The laser ablation atmospheric pressure photoionization (LAAPPI) and LDTD-APPI mass spectra of sage leaves (Salvia officinalis) using a field-deployable quadrupole ion trap MS display many similar ion peaks, as do the mass spectra of membrane grown biofilms of Pseudomonas aeruginosa. These results indicate that LDTD-APPI method should be useful for in-field sampling of plant and microbial communities, for example, by portable ambient MS. The feasibility of many portable MS applications is facilitated by the availability of relatively low cost, portable, battery-powered diode lasers. LDTD could also be coupled with plasma- or electrospray-based ionization for the analysis of a variety of solid samples.

On-target digestion of collected bacteria for MALDI mass spectrometry.

PubMed

Dugas, Alton J; Murray, Kermit K

2008-10-03

An on-target protein digestion system was developed for the identification of microorganisms in collected bioaerosols using off-line matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). Bacteria analysis techniques based on MALDI-MS were adapted for use with an orthogonal MALDI quadrupole-time-of-flight mass spectrometer. Bioaerosols were generated using a pneumatic nebulizer and infused into a chamber for sampling. An Andersen N6 single-stage impactor was used to collect the bioaerosols on a MALDI target. On-target digestion was carried out inside temporary mini-wells placed over the impacted samples. The wells served as miniature reactors for proteolysis. Collected test aerosol particles containing the protein cytochrome c and E. coli bacteria were proteolyzed in situ using trypsin or cyanogen bromide. A total of 19 unique proteins were identified for E. coli. Using the TOF-MS spectra of the digested samples, peptide mass mapping was performed using the MASCOT search engine and an iterative search technique.

Quantitative mass spectrometry methods for pharmaceutical analysis

PubMed Central

Loos, Glenn; Van Schepdael, Ann

2016-01-01

Quantitative pharmaceutical analysis is nowadays frequently executed using mass spectrometry. Electrospray ionization coupled to a (hybrid) triple quadrupole mass spectrometer is generally used in combination with solid-phase extraction and liquid chromatography. Furthermore, isotopically labelled standards are often used to correct for ion suppression. The challenges in producing sensitive but reliable quantitative data depend on the instrumentation, sample preparation and hyphenated techniques. In this contribution, different approaches to enhance the ionization efficiencies using modified source geometries and improved ion guidance are provided. Furthermore, possibilities to minimize, assess and correct for matrix interferences caused by co-eluting substances are described. With the focus on pharmaceuticals in the environment and bioanalysis, different separation techniques, trends in liquid chromatography and sample preparation methods to minimize matrix effects and increase sensitivity are discussed. Although highly sensitive methods are generally aimed for to provide automated multi-residue analysis, (less sensitive) miniaturized set-ups have a great potential due to their ability for in-field usage. This article is part of the themed issue ‘Quantitative mass spectrometry’. PMID:27644982

Online Hydrophobic Interaction Chromatography-Mass Spectrometry for the Analysis of Intact Monoclonal Antibodies.

PubMed

Chen, Bifan; Lin, Ziqing; Alpert, Andrew J; Fu, Cexiong; Zhang, Qunying; Pritts, Wayne A; Ge, Ying

2018-06-19

Therapeutic monoclonal antibodies (mAbs) are an important class of drugs for a wide spectrum of human diseases. Liquid chromatography (LC) coupled to mass spectrometry (MS) is one of the techniques in the forefront for comprehensive characterization of analytical attributes of mAbs. Among various protein chromatography modes, hydrophobic interaction chromatography (HIC) is a popular offline nondenaturing separation technique utilized to purify and analyze mAbs, typically with the use of non-MS-compatible mobile phases. Herein we demonstrate for the first time, the application of direct HIC-MS and HIC-tandem MS (MS/MS) with electron capture dissociation (ECD) for analyzing intact mAbs on quadrupole-time-of-flight (Q-TOF) and Fourier transform ion cyclotron resonance (FTICR) mass spectrometers, respectively. Our method allows for rapid determination of relative hydrophobicity, intact masses, and glycosylation profiles of mAbs as well as sequence and structural characterization of the complementarity-determining regions in an online configuration.

Analysis of veterinary drug residues in frog legs and other aquacultured species using liquid chromatography quadrupole time-of-flight mass spectrometry.

PubMed

Turnipseed, Sherri B; Clark, Susan B; Storey, Joseph M; Carr, Justin R

2012-05-09

A liquid chromatography quadrupole time-of-flight (Q-TOF) mass spectrometry method was developed to analyze veterinary drug residues in frog legs and other aquacultured species. Samples were extracted using a procedure based on a method developed for the analysis of fluoroquinolones (FQs) in fish. Briefly, the tissue was extracted with dilute acetic acid and acetonitrile with added sodium chloride. After centrifugation, the extracts were evaporated and reconstituted in mobile phase. A molecular weight cutoff filter was used to clean up the final extract. A set of target compounds, including trimethoprim, sulfamethoxazole, chloramphenicol, quinolones, and FQs, was used to validate the method. Screening of residues was accomplished by collecting TOF (MS¹) data and comparing the accurate mass and retention times of compounds to a database containing information for veterinary drugs. An evaluation of the MS data in fortified frog legs indicated that the target compounds could be consistently detected at the level of concern. The linearity and recoveries from matrix were evaluated for these analytes to estimate the amount of residue present. MS/MS data were also generated from precursor ions, and the mass accuracy of the product ions for each compound was compared to theoretical values. When the method was used to analyze imported frog legs, many of these residues were found in the samples, often in combination and at relatively high concentrations (>10 ng/g). The data from these samples were also evaluated for nontarget analytes such as residue metabolites and other chemotherapeutics.

Use of specific peptide biomarkers for quantitative confirmation of hidden allergenic peanut proteins Ara h 2 and Ara h 3/4 for food control by liquid chromatography-tandem mass spectrometry.

PubMed

Careri, M; Costa, A; Elviri, L; Lagos, J-B; Mangia, A; Terenghi, M; Cereti, A; Garoffo, L Perono

2007-11-01

A liquid chromatography-electrospray-tandem mass spectrometry (LC-ESI-MS-MS) method based on the detection of biomarker peptides from allergenic proteins was devised for confirming and quantifying peanut allergens in foods. Peptides obtained from tryptic digestion of Ara h 2 and Ara h 3/4 proteins were identified and characterized by LC-MS and LC-MS-MS with a quadrupole-time of flight mass analyzer. Four peptides were chosen and investigated as biomarkers taking into account their selectivity, the absence of missed cleavages, the uniform distribution in the Ara h 2 and Ara h 3/4 protein isoforms together with their spectral features under ESI-MS-MS conditions, and good repeatability of LC retention time. Because of the different expression levels, the selection of two different allergenic proteins was proved to be useful in the identification and univocal confirmation of the presence of peanuts in foodstuffs. Using rice crisp and chocolate-based snacks as model food matrix, an LC-MS-MS method with triple quadrupole mass analyzer allowed good detection limits to be obtained for Ara h 2 (5 microg protein g(-1) matrix) and Ara h 3/4 (1 microg protein g(-1) matrix). Linearity of the method was established in the 10-200 microg g(-1) range of peanut proteins in the food matrix investigated. Method selectivity was demonstrated by analyzing tree nuts (almonds, pecan nuts, hazelnuts, walnuts) and food ingredients such as milk, soy beans, chocolate, cornflakes, and rice crisp.

Improved sensitivity of ochratoxin A analysis in coffee using high-performance liquid chromatography with hybrid triple quadrupole-linear ion trap mass spectrometry (LC-QqQLIT-MS/MS).

PubMed

Kokina, Aija; Pugajeva, Iveta; Bartkevics, Vadims

2016-01-01

A novel and sensitive method utilising high-performance liquid chromatography coupled to triple quadrupole-linear ion trap mass spectrometry (LC-QqQLIT-MS/MS) was developed in order to analyse the content of ochratoxin A (OTA) in coffee samples. The introduction of the triple-stage MS scanning mode (MS(3)) has been shown to increase greatly sensitivity and selectivity by eliminating the high chromatographic baseline caused by interference of complex coffee matrices. The analysis included the sample preparation procedure involving extraction of OTA using a methanol-water mixture and clean-up by immunoaffinity columns and detection using the MS(3) scanning mode of LC-QqQLIT-MS/MS. The proposed method offered a good linear correlation (r(2) > 0.998), excellent precision (RSD < 2.9%) and recovery (94%). The limit of quantification (LOQ) for coffee beans and espresso beverages was 0.010 and 0.003 µg kg(-1), respectively. The developed procedure was compared with traditional methods employing liquid chromatography coupled to fluorescent and tandem quadrupole detectors in conjunction with QuEChERS and solid-phase extraction. The proposed method was successfully applied to the determination of OTA in 15 samples of coffee beans and in 15 samples of espresso coffee beverages obtained from the Latvian market. OTA was found in 10 samples of coffee beans and in two samples of espresso in the ranges of 0.018-1.80 µg kg(-1) and 0.020-0.440 µg l(-1), respectively. No samples exceeded the maximum permitted level of OTA in the European Union (5.0 µg kg(-1)).

Simultaneous determination of polysaccharides and 21 nucleosides and amino acids in different tissues of Salvia miltiorrhiza from different areas by UV-visible spectrophotometry and UHPLC with triple quadrupole MS/MS.

PubMed

Xiang, Xiang; Sha, Xiuxiu; Su, Shulan; Zhu, Zhenhua; Guo, Sheng; Yan, Hui; Qian, Dawei; Duan, Jin-Ao

2018-03-01

Salvia miltiorrhiza, a traditional Chinese medicine, is a widely used herbal medicine to treat cardiovascular and cerebrovascular diseases. In this study, ultraviolet (UV)-visible spectrophotometry and ultra-high performance liquid chromatography with triple quadrupole tandem mass spectrometry analytical methods were used for rapid quantification of polysaccharides and 21 nucleosides and amino acids in S. miltiorrhiza to determine 17 samples of different tissues from different areas. Based on the total contents, hierarchical clustering analysis and principal components analysis were performed to classify these samples. The established methods were validated with good linearity, precision, repeatability, stability, and recovery. Chemical analysis revealed a higher content of total analytes in the sample of inflorescence from Nanjing (34.17 mg/g), sample of root and rhizome from Shaanxi (34.13 mg/g) and sample of stem and leaf from Nanjing (31.14 mg/g), respectively, indicating that root and rhizome from Shaanxi and the aerial parts from Nanjing exhibited the highest quality due to their highest content. In addition, contents of nucleosides and amino acids in the aerial parts (14.67 mg/g) were much higher than that in roots and rhizomes (9.17 mg/g). This study suggested that UV-visible spectrophotometry and ultra-high performance liquid chromatography with triple quadrupole tandem mass spectrometry are effective techniques to analyze polysaccharides, nucleosides, and amino acids in plants, and they provided valuable information for the development and utilization value of the aerial parts of S. miltiorrhiza. This analysis would also provide useful information for the quality control of S. miltiorrhiza. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Investigations of chemical warfare agents and toxic industrial compounds with proton-transfer-reaction mass spectrometry for a real-time threat monitoring scenario.

PubMed

Kassebacher, Thomas; Sulzer, Philipp; Jürschik, Simone; Hartungen, Eugen; Jordan, Alfons; Edtbauer, Achim; Feil, Stefan; Hanel, Gernot; Jaksch, Stefan; Märk, Lukas; Mayhew, Chris A; Märk, Tilmann D

2013-01-30

Security and protection against terrorist attacks are major issues in modern society. One especially challenging task is the monitoring and protection of air conditioning and heating systems of buildings against terrorist attacks with toxic chemicals. As existing technologies have low selectivity, long response times or insufficient sensitivity, there is a need for a novel approach such as we present here. We have analyzed various chemical warfare agents (CWAs) and/or toxic industrial compounds (TICs) and related compounds, namely phosgene, diphosgene, chloroacetone, chloroacetophenone, diisopropylaminoethanol, and triethyl phosphate, utilizing a high-resolution proton-transfer-reaction time-of-flight mass spectrometry (PTR-TOFMS) instrument with the objective of finding key product ions and their intensities, which will allow a low-resolution quadrupole mass spectrometry based PTR-MS system to be used with high confidence in the assignment of threat agents in the atmosphere. We obtained high accuracy PTR-TOFMS mass spectra of the six compounds under study at two different values for the reduced electric field in the drift tube (E/N). From these data we have compiled a table containing product ions, and isotopic and E/N ratios for highly selective threat compound detection with a compact and cost-effective quadrupole-based PTR-MS instrument. Furthermore, using chloroacetophenone (tear gas), we demonstrated that this instrument's response is highly linear in the concentration range of typical Acute Exposure Guideline Levels (AEGLs). On the basis of the presented results it is possible to develop a compact and cost-effective PTR-QMS instrument that monitors air supply systems and triggers an alarm as soon as the presence of a threat agent is detected. We hope that this real-time surveillance device will help to seriously improve safety and security in environments vulnerable to terrorist attacks with toxic chemicals. Copyright © 2012 John Wiley & Sons, Ltd.

Tandem mass spectrometry of isomeric aniline-labeled N-glycans separated on porous graphitic carbon: Revealing the attachment position of terminal sialic acids and structures of neutral glycans.

PubMed

Michael, Claudia; Rizzi, Andreas M

2015-07-15

Quantitative monitoring of changes in the N-glycome upon disease has gained significance in the context of biomarker discovery. Separation and quantification of isobaric glycan isomers can be attained by using high-performance liquid chromatography/electrospray ionization mass spectrometry (HPLC/ESI-MS). Collision-induced dissociation (CID)-based fragmentation of separated isobaric glycans is evaluated in respect to its potential of providing fragment ions specific for the linkage positions of terminal sialic acids and the presence of intersecting GlcNAc moieties, respectively. N-Glycans were labeled via reductive amination using (12)C6-aniline and (13)C6-aniline as isotope-coded labeling reagents. The differently labeled glycans were merged and separated into various species using a porous graphitic carbon (PGC) stationary phase. Identification of structural features of separated isobaric isomers was performed by CID-based tandem mass spectrometry (MS/MS) carried out in a quadrupole time-of-flight (QqTOF) or a quadrupole ion-trap (IT) mass spectrometer. Working in the negative ion mode, new diagnostic CID fragment ions could be found that are indicative for the α2,6-type linkage of sialic acids. Other diagnostic ions, identified before as being indicative for the substitution of the 6-antenna, could be confirmed as being of relevance also in the case of aniline labeling. In the positive ion mode, CID fragment ions indicative for the structure of short neutral N-glycans were identified. One new diagnostic ion specific for the linkage position of the terminal sialic acids and one for the presence of bisecting GlcNAc in N-glycans were identified. The aniline label introduced for improved relative quantitation in MS(1) was found not to significantly alter the CID fragmentation patterns that were reported previously by other authors for unlabeled/reduced glycans or for glycans with more polar labels. Copyright © 2015 John Wiley & Sons, Ltd.

Multiclass screening of >200 pharmaceutical and other residues in aquatic foods by ultrahigh-performance liquid chromatography-quadrupole-Orbitrap mass spectrometry.

PubMed

Kong, Cong; Wang, Yang; Huang, Yuanfei; Yu, Huijuan

2018-05-11

A quick screening method of more than 200 pharmaceutical and other residues in aquatic foods based on ultrahigh-performance liquid chromatography-quadrupole-Orbitrap mass spectrometry (UHPLC-Q/Orbitrap MS) was established. In this method, after the addition of 200 μL of 1 M EDTA-Na 2 , 2 g of each sample homogenate was extracted successively with 10 mL of acetonitrile and 10 mL of ethyl acetate. The extracts were combined, dried under nitrogen flow, and redissolved in 0.1% formic acid in acetonitrile/water (4:6, v/v) for analysis. The prepared samples were analyzed by UHPLC- Q/Orbitrap MS system in Full MS/ddMS 2 (full-scan data-dependent MS/MS) mode. Compound identification was performed through comparison of the sample data with the database for standard chemicals, including the retention time, precursor ion, product ions, and isotope pattern for all 206 compounds. Five different aquatic food matrices (carp, shrimp, crab, eel, and mussel) spiked with the analytes at 1, 10, and 50 ng/g were evaluated to assess recoveries, precision, matrix effects, stability, and detection limits using the method. UHPLC analyses required 25 min, and 178-200 analytes met identification criteria at 50 ng/g depending on the matrix. Furthermore, practical application of this method for real samples displayed strong screening capability. Graphical abstract A quick screening method of >200 pharmaceutical and other residues in aquatic foods based on ultrahighperformance liquid chromatography-quadrupole-Orbitrap mass spectrometer was established. Fivedifferent aquatic food matrices, including carp, shrimp, crab, eel and mussel, were studied to evaluatescreen limit at 1, 10 and 50 μg·kg-1 level. Results suggest the high reliability, high time-efficiency and goodsimplicity of the method.

Use of an online extraction liquid chromatography quadrupole time-of-flight tandem mass spectrometry method for the characterization of polyphenols in Citrus paradisi cv. Changshanhuyu peel.

PubMed

Tong, Chaoying; Peng, Mijun; Tong, Runna; Ma, Ruyi; Guo, Keke; Shi, Shuyun

2018-01-19

Chemical profiling of natural products by high performance liquid chromatography (HPLC) was critical for understanding of their clinical bioactivities, and sample pretreatment steps have been considered as a bottleneck for analysis. Currently, concerted efforts have been made to develop sample pretreatment methods with high efficiency, low solvent and time consumptions. Here, a simple and efficient online extraction (OLE) strategy coupled with HPLC-diode array detector-quadrupole time-of-flight tandem mass spectrometry (HPLC-DAD-QTOF-MS/MS) was developed for rapid chemical profiling. For OLE strategy, guard column inserted with ground sample (2 mg) instead of sample loop was connected with manual injection valve, in which components were directly extracted and transferred to HPLC-DAD-QTOF-MS/MS system only by mobile phase without any extra time, solvent, instrument and operation. By comparison with offline heat-reflux extraction of Citrus paradisi cv. Changshanhuyu (Changshanhuyu) peel, OLE strategy presented higher extraction efficiency perhaps because of the high pressure and gradient elution mode. A total of twenty-two secondary metabolites were detected according to their retention times, UV spectra, exact mass, and fragmentation ions in MS/MS spectra, and nine of them were discovered in Changshanhuyu peel for the first time to our knowledge. It is concluded that the developed OLE-HPLC-DAD-QTOF-MS/MS system offers new perspectives for rapid chemical profiling of natural products. Copyright © 2017 Elsevier B.V. All rights reserved.

Online extraction-high performance liquid chromatography-diode array detector-quadrupole time-of-flight tandem mass spectrometry for rapid flavonoid profiling of Fructus aurantii immaturus.

PubMed

Tong, Runna; Peng, Mijun; Tong, Chaoying; Guo, Keke; Shi, Shuyun

2018-03-01

Chemical profiling of natural products by high performance liquid chromatography (HPLC) was critical for understanding of their clinical bioactivities, and sample pretreatment steps have been considered as a bottleneck for analysis. Currently, concerted efforts have been made to develop sample pretreatment methods with high efficiency, low solvent and time consumptions. Here, a simple and efficient online extraction (OLE) strategy coupled with HPLC-diode array detector-quadrupole time-of-flight tandem mass spectrometry (HPLC-DAD-QTOF-MS/MS) was developed for rapid chemical profiling. For OLE strategy, guard column inserted with ground sample (2 mg) instead of sample loop was connected with manual injection valve, in which components were directly extracted and transferred to HPLC-DAD-QTOF-MS/MS system only by mobile phase without any extra time, solvent, instrument and operation. By comparison with offline heat-reflux extraction for Fructus aurantii immaturus (Zhishi), OLE strategy presented higher extraction efficiency perhaps because of the high pressure and gradient elution mode. A total of eighteen flavonoids were detected according to their retention times, UV spectra, exact mass, and fragmentation ions in MS/MS spectra, and compound 9, natsudaidain-3-O-glucoside, was discovered in Zhishi for the first time. It is concluded that the developed OLE-HPLC-DAD-QTOF-MS/MS system offers new perspectives for rapid chemical profiling of natural products. Copyright © 2018. Published by Elsevier B.V.

Determination of exogenous epigallocatechin gallate peracetate in mouse plasma using liquid chromatography with quadrupole time-of-flight mass spectrometry.

PubMed

Chu, Kai On; Man, Gene Chi Wai; Chan, Kwok Ping; Chu, Ching Yan; Chan, Tak Hang; Pang, Chi Pui; Wang, Chi Chiu

2014-12-01

A robust method for the quantitation of epigallocatechin gallate peracetate in plasma for pharmacokinetic studies is lacking. We have developed a validated method to quantify this compound using liquid chromatography with quadrupole time-of-flight mass spectrometry with isopropanol and tert-butyl methyl ether (3:10) extraction and thin-layer chromatography purification. The epigallocatechin gallate peracetate-1-(13) C8 isotope was used as an internal standard. The linear range (r(2) > 0.9950) was from 0.05 to 100.00 μg/mL. The lower limit of quantification of the method was 0.05 μg/mL. Reproducibility, coefficient of variation, was between 0.7 and 12.6% (n = 6), accuracy between 83.7 and 104.6% (n = 5), and recovery ranged from 82.4 to 109.0% (n = 4). Ion suppression was approximately 40%. No mass spectral peaks were found to interfere between the standard and internal standard or the blank plasma extracts. Epigallocatechin gallate peracetate in plasma was stably stored at -80°C over three months even after three freeze-thaw cycles. Extracts were stable in the sampler at 4°C for over 48 h. Plasma levels were maintained at 1.36 μg/mL for 360 min after intraorbital intravenous injection at 50 mg/kg in mice. This method can be used to reliably measure epigallocatechin gallate peracetate in plasma for pharmacokinetic studies. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Profiling and characterizing skin ceramides using reversed-phase liquid chromatography-quadrupole time-of-flight mass spectrometry.

PubMed

t'Kindt, Ruben; Jorge, Lucie; Dumont, Emmie; Couturon, Pauline; David, Frank; Sandra, Pat; Sandra, Koen

2012-01-03

An LC-MS based method for the profiling and characterization of ceramide species in the upper layer of human skin is described. Ceramide samples, collected by tape stripping of human skin, were analyzed by reversed-phase liquid chromatography coupled to high-resolution quadrupole time-of-flight mass spectrometry operated in both positive and negative electrospray ionization mode. All known classes of ceramides could be measured in a repeatable manner. Furthermore, the data set showed several undiscovered ceramides, including a class with four hydroxyl functionalities in its sphingoid base. High-resolution MS/MS fragmentation spectra revealed that each identified ceramide species is composed of several skeletal isomers due to variation in carbon length of the respective sphingoid bases and fatty acyl building blocks. The resulting variety in skeletal isomers has not been previously demonstrated. It is estimated that over 1000 unique ceramide structures could be elucidated in human stratum corneum. Ceramide species with an even and odd number of carbon atoms in both chains were detected in all ceramide classes. Acid hydrolysis of the ceramides, followed by LC-MS analysis of the end-products, confirmed the observed distribution of both sphingoid bases and fatty acyl groups in skin ceramides. The study resulted in an accurate mass retention time library for targeted profiling of skin ceramides. It is furthermore demonstrated that targeted data processing results in an improved repeatability versus untargeted data processing (72.92% versus 62.12% of species display an RSD < 15%). © 2011 American Chemical Society

Photolysis of pharmaceuticals and personal care products in the marine environment under simulated sunlight conditions: irradiation and identification.

PubMed

Ali, Aasim Musa Mohamed; Kallenborn, Roland; Sydnes, Leiv Kristen; Rønning, Helene Thorsen; Alarif, Walied Mohamed; Al-Lihaibi, Sultan

2017-06-01

The photochemical fate of 16 pharmaceuticals and personal care products (PPCPs) found in the environment has been studied under controlled laboratory conditions applying a sunlight simulator. Aqueous samples containing PPCPs at environmentally relevant concentrations were extracted by solid-phase extraction (SPE) after irradiation. The exposed extracts were subsequently analysed by liquid chromatography combined with triple quadrupole mass spectrometry (HPLC-MS/MS) for studying the kinetics of photolytic transformations. Almost all exposed PPCPs appeared to react with a half-life time (τ 1/2 ) of less than 30 min. For ranitidine, sulfamethoxazole, diclofenac, warfarin, sulfamethoxazole and ciprofloxacin, τ 1/2 was found to be even less than 5 min. The structures of major photolysis products were determined using quadrupole-time-of-flight mass spectrometry (QToF) and spectroscopic data reported in the literature. For diclofenac, the transformation products carbazol-1-yl-acidic acid and 8-chloro-9H-carbazol-1-yl-acetic acid were identified based on the mass/charge ratio of protonated ions and their fragmentation pattern in negative electrospray ionization (ESI - -QTOF). Irradiation of carbamazepine resulted in three known products: acridine, carbamazepine-10,11-epoxide, and 10,11-dihydro-10,11-dihydroxy-carbamazepine, whereas acetaminophen was photolytically transformed to 1-(2-amino-5 hydroxyphenyl) ethenone. These photochemical products were subsequently identified in seawater or fish samples collected at sites exposed to wastewater effluents on the Saudi Arabian coast of the Red Sea.

Metabolites identification of harmane in vitro/in vivo in rats by ultra-performance liquid chromatography combined with electrospray ionization quadrupole time-of-flight tandem mass spectrometry.

PubMed

Li, Shuping; Liu, Wei; Teng, Liang; Cheng, Xuemei; Wang, Zhengtao; Wang, Changhong

2014-04-01

Harmane, a β-carboline alkaloid with a wide spectrum of pharmacological activities, is naturally present in the human diet, in numerous foodstuffs and in hallucinogenic plants such as Peganum harmala, Banisteriopsis caapi and Tribulus terrestris. However, the precise metabolic fate of harmane remains unknown. In order to know whether harmane is extensively metabolized, a rapid and sensitive method using ultra-performance liquid chromatography combined with electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UPLC/ESI-QTOF-MS) was used to analyze the metabolic profile of harmane in vitro and in vivo in rats. A total of 21 metabolites were identified from the rat liver microsomes and rat liver S9 (9), rat urine (11), feces (16), bile (16), and plasma (10) after a single oral administration of harmane using MetaboLynx™ and MassFragment ™ software tools. It indicated that the biliary and faecal clearance were the major excretion routes for harmane as well as its metabolites. The specific CLogP values combined with different acidic and alkaline mobile phase were helpful and useful for distinguishing N-oxidation and monohydroxylation metabolites. The metabolic transformation pathways of harmane included monohydroxylation, dihydroxylation, N-oxidation, O-glucuronide conjugation, O-sulphate conjugation, and glutathione conjugation. In conclusion, this study showed an insight into the metabolism of harmane. Copyright © 2014 Elsevier B.V. All rights reserved.

Identification and analysis of chemical constituents and rat serum metabolites in Suan-Zao-Ren granule using ultra high performance liquid chromatography quadrupole time-of-flight mass spectrometry combined with multiple data processing approaches.

PubMed

Du, Yiyang; He, Bosai; Li, Qing; He, Jiao; Wang, Di; Bi, Kaishun

2017-07-01

Suan-Zao-Ren granule is widely used to treat insomnia in China. However, because of the complexity and diversity of the chemical compositions in traditional Chinese medicine formula, the comprehensive analysis of constituents in vitro and in vivo is rather difficult. In our study, an ultra high performance liquid chromatography with quadrupole time-of-flight mass spectrometry and the PeakView® software, which uses multiple data processing approaches including product ion filter, neutral loss filter, and mass defect filter, method was developed to characterize the ingredients and rat serum metabolites in Suan-Zao-Ren granule. A total of 101 constituents were detected in vitro. Under the same analysis conditions, 68 constituents were characterized in rat serum, including 35 prototype components and 33 metabolites. The metabolic pathways of main components were also illustrated. Among them, the metabolic pathways of timosaponin AI were firstly revealed. The bioactive compounds mainly underwent the phase I metabolic pathways including hydroxylation, oxidation, hydrolysis, and phase II metabolic pathways including sulfate conjugation, glucuronide conjugation, cysteine conjugation, acetycysteine conjugation, and glutathione conjugation. In conclusion, our results showed that this analysis approach was extremely useful for the in-depth pharmacological research of Suan-Zao-Ren granule and provided a chemical basis for its rational. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

[Determination of 11 mycotoxins in baked foods and raw materials by ultra performance liquid chromatography-quadrupole/electrostatic field orbitrap high-resolution mass spectrometry].

PubMed

Li, Rong; He, Chunmei; Yang, Luqi; Wang, Yong; Zhang, Pengjie; Gao, Yongqing

2017-08-08

A method for the determination of 11 mycotoxins in baked foods and raw materials by ultra-high performance liquid chromatography-quadrupole/electrostatic field orbitrap high-resolution mass spectrometry (UPLC-HRMS) is reported in this paper. The samples were extracted with 20 mL 90% (v/v) acetonitrile aqueous solution containing 1% (v/v) formic acid, and the extracts were salted out by 2.0 g MgSO 4 and 0.5 g NaCl, cleaned up by 300 mg C18. The analytes were carried out on a CORTECS C18 column (100 mm×2.1 mm, 1.6 μ m) by gradient elution with 2 mmol/L ammonium acetate with 0.1% (v/v) formic acid aqueous solution and 2 mmol/L ammonium acetate methanol with 0.1% (v/v) formic acid. The results showed that the 11 mycotoxins had good linear relationships in their respective mass concentration ranges. The correlation coefficients were not less than 0.9960 and the limits of quantitation (LOQs) were from 0.15 to 20.00 μ g/kg. The recoveries of the 11 mycotoxins in bread ranged from 64.38% to 122.61% with the relative standard deviations (RSDs) from 1.52% to 12.99% at three spiked levels ( n =6). The method is demonstrated to be simple, fast, highly sensitive, reliable and it is effective to detect common mycotoxins in baked foods and raw materials.

Chemical Profiling of Re-Du-Ning Injection by Ultra-Performance Liquid Chromatography Coupled with Electrospray Ionization Tandem Quadrupole Time-of-Flight Mass Spectrometry through the Screening of Diagnostic Ions in MSE Mode

PubMed Central

Wang, Zhenzhong; Geng, Jianliang; Dai, Yi; Xiao, Wei; Yao, Xinsheng

2015-01-01

The broad applications and mechanism explorations of traditional Chinese medicine prescriptions (TCMPs) require a clear understanding of TCMP chemical constituents. In the present study, we describe an efficient and universally applicable analytical approach based on ultra-performance liquid chromatography coupled to electrospray ionization tandem quadrupole time-of-flight mass spectrometry (UPLC-ESI-Q/TOF-MS) with the MSE (E denotes collision energy) data acquisition mode, which allowed the rapid separation and reliable determination of TCMP chemical constituents. By monitoring diagnostic ions in the high energy function of MSE, target peaks of analogous compounds in TCMPs could be rapidly screened and identified. “Re-Du-Ning” injection (RDN), a eutherapeutic traditional Chinese medicine injection (TCMI) that has been widely used to reduce fever caused by viral infections in clinical practice, was studied as an example. In total, 90 compounds, including five new iridoids and one new sesquiterpene, were identified or tentatively characterized by accurate mass measurements within 5 ppm error. This analysis was accompanied by MS fragmentation and reference standard comparison analyses. Furthermore, the herbal sources of these compounds were unambiguously confirmed by comparing the extracted ion chromatograms (EICs) of RDN and ingredient herbal extracts. Our work provides a certain foundation for further studies of RDN. Moreover, the analytical approach developed herein has proven to be generally applicable for profiling the chemical constituents in TCMPs and other complicated mixtures. PMID:25875968

In house validation of a high resolution mass spectrometry Orbitrap-based method for multiple allergen detection in a processed model food.

PubMed

Pilolli, Rosa; De Angelis, Elisabetta; Monaci, Linda

2018-02-13

In recent years, mass spectrometry (MS) has been establishing its role in the development of analytical methods for multiple allergen detection, but most analyses are being carried out on low-resolution mass spectrometers such as triple quadrupole or ion traps. In this investigation, performance provided by a high resolution (HR) hybrid quadrupole-Orbitrap™ MS platform for the multiple allergens detection in processed food matrix is presented. In particular, three different acquisition modes were compared: full-MS, targeted-selected ion monitoring with data-dependent fragmentation (t-SIM/dd2), and parallel reaction monitoring. In order to challenge the HR-MS platform, the sample preparation was kept as simple as possible, limited to a 30-min ultrasound-aided protein extraction followed by clean-up with disposable size exclusion cartridges. Selected peptide markers tracing for five allergenic ingredients namely skim milk, whole egg, soy flour, ground hazelnut, and ground peanut were monitored in home-made cookies chosen as model processed matrix. Timed t-SIM/dd2 was found the best choice as a good compromise between sensitivity and accuracy, accomplishing the detection of 17 peptides originating from the five allergens in the same run. The optimized method was validated in-house through the evaluation of matrix and processing effects, recoveries, and precision. The selected quantitative markers for each allergenic ingredient provided quantification of 60-100 μg ingred /g allergenic ingredient/matrix in incurred cookies.

Chemical Ionization Mass Spectrometry.

DTIC Science & Technology

1980-01-30

8217 ’ b o t5D&(( Irff irent from Controlling Office) IS. SECURITY CLASS. (of this report) 1< ; ~ / 1-j~. Unclassified 1S. DECLASSI FI CATION/DOWNGRADING...level in industrial sludge without any prior chromatogaphic or wet chemical separation of this comolex matrix. D. F. Hunt, J. Shabanowitz, and A. B ...Analytical Cheristry, April 1979 12)D. F. Hunt , J. Shabanowitz, and A. B . Giordani, Collision Activated Decompositions or Megative Ions in a Triple Quadrupole

Reversed-phase ultra-high-performance liquid chromatography coupled to electrospray ionization-quadrupole-time-of-flight mass spectrometry as a powerful tool for metabolic profiling of vegetables: Lactuca sativa as an example of its application.

PubMed

Abu-Reidah, I M; Contreras, M M; Arráez-Román, D; Segura-Carretero, A; Fernández-Gutiérrez, A

2013-10-25

Lettuce (Lactuca sativa), a leafy vegetal widely consumed worldwide, fresh cut or minimally processed, constitutes a major dietary source of natural antioxidants and bioactive compounds. In this study, reversed-phase ultra-high-performance liquid chromatography (RP-UHPLC) coupled to electrospray ionization-quadrupole-time-of-flight mass spectrometry (ESI-QTOF-MS) was applied for the comprehensive profiling of polar and semi-polar metabolites from three lettuce cultivars (baby, romaine, and iceberg). The UHPLC systems allowed the use of a small-particle-size C18 column (1.8 μm), with very fine resolution for the separation of up to seven isomers, and the QTOF mass analyzer enabled sensitive detection with high mass resolution and accuracy in full scan. Thus, a total of 171 compounds were tentatively identified by matching their accurate mass signals and suggested molecular formula with those previously reported in family Asteraceae. Afterwards, their structures were also corroborated by the MS/MS data provided by the QTOF analyzer. Well-known amino acids, organic acids, sesquiterpene lactones, phenolic acids and flavonoids were characterized, e.g. lactucin, lactucopicrin, caftaric acid, chlorogenic acid, caffeoylmalic acid, chicoric acid, isochlorogenic acid A, luteolin, and quercetin glycosides. For this plant species, this is the first available report of several isomeric forms of the latter polyphenols and other types of components such as nucleosides, peptides, and tryptophan-derived alkaloids. Remarkably, 10 novel structures formed by the conjugation of known amino acids and sesquiterpene lactones were also proposed. Thus, the methodology applied is a useful option to develop an exhaustive metabolic profiling of plants that helps to explain their potential biological activities and folk uses. Copyright © 2013 Elsevier B.V. All rights reserved.

Metabolomic approaches for orange origin discrimination by ultra-high performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry.

PubMed

Díaz, Ramon; Pozo, Oscar J; Sancho, Juan V; Hernández, Félix

2014-08-15

In this work, hybrid quadrupole time-of-flight mass spectrometer (QTOF MS) coupled to ultra high performance liquid chromatography (UHPLC) has been used for biomarkers identification for correct authentication of Valencia (Spain) oranges. Differentiation from foreign Argentinean, Brazilian and South African oranges has been carried out using XCMS application and multivariate analysis to UHPLC-(Q)TOF MS data acquired in both, positive and negative ionisation modes. Several markers have been found and corroborated by analysing two seasons samples. A seasonal independent marker was found and its structure elucidated using accurate mass data and MS(E) fragmentation spectrum information. Empirical formula was searched in Reaxys database applying sub-structure filtering from the fragments obtained. Three possible structures were found and citrusin D, a compound present in sweet oranges, has been identified as the most plausible as it fits better with the product ion scan performed for this compound. As a result of data obtained in this work, citrusin D is suggested as a potential marker to distinguish the geographic origin of oranges. Copyright © 2014 Elsevier Ltd. All rights reserved.

Development of a fast screening and confirmatory method by liquid chromatography-quadrupole-time-of-flight mass spectrometry for glucuronide-conjugated methyltestosterone metabolite in tilapia.

PubMed

Amarasinghe, Kande; Chu, Pak-Sin; Evans, Eric; Reimschuessel, Renate; Hasbrouck, Nicholas; Jayasuriya, Hiranthi

2012-05-23

This paper describes the development of a fast method to screen and confirm methyltestosterone 17-O-glucuronide (MT-glu) in tilapia bile. The method consists of solid-phase extraction (SPE) followed by high-performance liquid chromatography-mass spectrometry. The system used was an Agilent 6530 Q-TOF with an Agilent Jet stream electrospray ionization interface. The glucuronide detected in the bile was characterized as MT-glu by comparison with a chemically synthesized standard. MT-glu was detected in bile for up to 7 days after dosing. Semiquantification was done with matrix-matched calibration curves, because MT-glu showed signal suppression due to matrix effects. This method provides a suitable tool to monitor the illegal use of methyltestosterone in tilapia culture.

Formation of multiply charged ions from large molecules using massive-cluster impact.

PubMed

Mahoney, J F; Cornett, D S; Lee, T D

1994-05-01

Massive-cluster impact is demonstrated to be an effective ionization technique for the mass analysis of proteins as large as 17 kDa. The design of the cluster source permits coupling to both magnetic-sector and quadrupole mass spectrometers. Mass spectra are characterized by the almost total absence of chemical background and a predominance of multiply charged ions formed from 100% glycerol matrix. The number of charge states produced by the technique is observed to range from +3 to +9 for chicken egg lysozyme (14,310 Da). The lower m/z values provided by higher charge states increase the effective mass range of analyses performed with conventional ionization by fast-atom bombardment or liquid secondary ion mass spectrometry.

Surface-Induced Dissociation of Protein Complexes in a Hybrid Fourier Transform Ion Cyclotron Resonance Mass Spectrometer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yan, Jing; Zhou, Mowei; Gilbert, Joshua D.

Mass spectrometry continues to develop as a valuable tool in the analysis of proteins and protein complexes. In protein complex mass spectrometry studies, surface-induced dissociation (SID) has been successfully applied in quadrupole time-of-flight (Q-TOF) instruments. SID provides structural information on noncovalent protein complexes that is complementary to other techniques. However, the mass resolution of Q-TOF instruments can limit the information that can be obtained for protein complexes by SID. Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) provides ultrahigh resolution and ultrahigh mass accuracy measurements. Here in this study, an SID device was designed and successfully installed in amore » hybrid FT-ICR instrument in place of the standard gas collision cell. The SID-FT-ICR platform has been tested with several protein complex systems (homooligomers, a heterooligomer, and a protein-ligand complex, ranging from 53 to 85 kDa), and the results are consistent with data previously acquired on Q-TOF platforms, matching predictions from known protein interface information. Lastly, SID fragments with the same m/z but different charge states are well-resolved based on distinct spacing between adjacent isotope peaks, and the addition of metal cations and ligands can also be isotopically resolved with the ultrahigh mass resolution available in FT-ICR.« less

Surface-Induced Dissociation of Protein Complexes in a Hybrid Fourier Transform Ion Cyclotron Resonance Mass Spectrometer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yan, Jing; Zhou, Mowei; Gilbert, Joshua D.

Mass spectrometry continues to develop as a valuable tool in the analysis of proteins and protein complexes. In protein complex mass spectrometry studies, surface-induced dissociation (SID) has been successfully applied in quadrupole time-of-flight (Q-TOF) instruments. SID provides structural information on non-covalent protein complexes that is complementary to other techniques. However, the mass resolution of Q-TOF instruments can limit the information that can be obtained for protein complexes by SID. Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) provides ultrahigh resolution and ultrahigh mass accuracy measurements. In this study, an SID device was designed and successfully installed in a hybridmore » FT-ICR instrument in place of the standard gas collision cell. The SID-FT-ICR platform has been tested with several protein complex systems (homooligomers, a heterooligomer, and a protein-ligand complex, ranging from 53 kDa to 85 kDa), and the results are consistent with data previously acquired on Q-TOF platforms, matching predictions from known protein interface information. SID fragments with the same m/z but different charge states are well-resolved based on distinct spacing between adjacent isotope peaks, and the addition of metal cations and ligands can also be isotopically resolved with the ultrahigh mass resolution available in FT-ICR.« less

Surface-Induced Dissociation of Protein Complexes in a Hybrid Fourier Transform Ion Cyclotron Resonance Mass Spectrometer

DOE PAGES

Yan, Jing; Zhou, Mowei; Gilbert, Joshua D.; ...

2016-12-02

Mass spectrometry continues to develop as a valuable tool in the analysis of proteins and protein complexes. In protein complex mass spectrometry studies, surface-induced dissociation (SID) has been successfully applied in quadrupole time-of-flight (Q-TOF) instruments. SID provides structural information on noncovalent protein complexes that is complementary to other techniques. However, the mass resolution of Q-TOF instruments can limit the information that can be obtained for protein complexes by SID. Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) provides ultrahigh resolution and ultrahigh mass accuracy measurements. Here in this study, an SID device was designed and successfully installed in amore » hybrid FT-ICR instrument in place of the standard gas collision cell. The SID-FT-ICR platform has been tested with several protein complex systems (homooligomers, a heterooligomer, and a protein-ligand complex, ranging from 53 to 85 kDa), and the results are consistent with data previously acquired on Q-TOF platforms, matching predictions from known protein interface information. Lastly, SID fragments with the same m/z but different charge states are well-resolved based on distinct spacing between adjacent isotope peaks, and the addition of metal cations and ligands can also be isotopically resolved with the ultrahigh mass resolution available in FT-ICR.« less

Simultaneous determination of zearalenone and its derivatives in edible vegetable oil by gel permeation chromatography and gas chromatography-triple quadrupole mass spectrometry.

PubMed

Qian, Mingrong; Zhang, Hu; Wu, Liqin; Jin, Nuo; Wang, Jianmei; Jiang, Kezhi

2015-01-01

A sensitive gas chromatographic-triple quadrupole mass spectrometric (GC-QqQ MS) analytical method, for the determination of zearalenone and its five derivatives in edible vegetable oil, was developed. After the vegetable oil samples were prepared using gel permeation chromatography, the eluent was collected, evaporated and dried with nitrogen gas. The residue was silylated with N,O-bis-trimethylsilyltrifluoroacetamide, containing 1% trimethylchlorosilane. GC-QqQ MS was performed in the reaction-monitoring mode to confirm and quantify mycotoxins in vegetable oil. The limits of quantitation were 0.03-0.2 μg kg(-1) for the six mycotoxins. The average recoveries, measured at 2, 20 and 200 μg kg(-1), were in the range 80.3-96.5%. Zearalenone was detected in the range 5.2-184.6 μg kg(-1) in nine maize oils and at 40.7 μg kg(-1) in a rapeseed oil from the local market. Copyright © 2014 Elsevier Ltd. All rights reserved.

The application of headspace gas chromatography coupled to tandem quadrupole mass spectrometry for the analysis of furan in baby food samples.

PubMed

Pugajeva, Iveta; Rozentale, Irina; Viksna, Arturs; Bartkiene, Elena; Bartkevics, Vadims

2016-12-01

Selective methodology employing a tandem quadrupole mass spectrometer coupled to a gas chromatograph with headspace autosampler (HS-GC-MS/MS) was elaborated in this study. Application of the elaborated procedure resulted in a limit of detection of 0.021μgkg(-1) and a limit of quantification of 0.071μgkg(-1). The mean recoveries during in-house validation ranged from 89% to 109%, and coefficients of variation for repeatability ranged from 4% to 11%. The proposed analytical method was applied for monitoring the furan content of 30 commercial baby food samples available on the Latvian retail market. The level of furan found in these samples varied from 0.45 to 81.9μgkg(-1), indicating that infants whose sole diet comprises baby food sold in jars and cans are exposed constantly to furan. Samples containing vegetables and meat had higher levels of furan than those containing only fruits. Copyright © 2016 Elsevier Ltd. All rights reserved.

Ultrasensitive Sample Quantitation via Selected Reaction Monitoring Using CITP/CZE-ESI-Triple Quadrupole MS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Chenchen; Lee, Cheng S.; Smith, Richard D.

2012-11-10

We demonstrate the direct coupling of transient capillary isotachophoresis/ capillary zone electrophoresis (CITP/CZE) with a high sensitivity triple quadrupole mass spectrometer operating in selected reaction monitoring (SRM) mode for sample quantitation. The capability of CITP/CZE for in situ sample enrichment and separation has been shown to significantly improve the analytical figures of merit. A linear dynamic range spanning more than 4 orders of magnitude was observed. An average signal-to-noise ratio (S/N) of 49.6 was observed for 50 attomoles of targeted peptide in the presence of a complex and much more abundant bovine serum albumin (BSA) digest products. A correlation ofmore » variation (CV) less than 10 % for peak area was measured from triplicate sample analyses at 50 pM peptide concentration, showing good reproducibility of this online CITP/CZE-SRM mass spectrometry (MS) platform, and with limit of quantitation (LOQ) demonstrated to be well below 50 pM.« less

MALDI-Imaging Mass Spectrometry of Ochratoxin A and Fumonisins in Mold-Infected Food.

PubMed

Hickert, Sebastian; Cramer, Benedikt; Letzel, Matthias C; Humpf, Hans-Ulrich

2016-09-06

Mycotoxins are toxic secondary metabolites produced by various fungi. Their distribution within contaminated material is of high interest to obtain insight into infection mechanisms and the possibility of reducing contamination during food processing. Various vegetable foodstuffs were infected with fungi of the genera Fusarium and Aspergillus. The localization of the produced mycotoxins was studied by matrix assisted laser desorption ionization time of flight imaging mass spectrometry (MALDI-MSI) of cryosections obtained from infected material. The results were confirmed by HPLC-electrospray ionization triple quadrupole mass spectrometry (HPLC/MS/MS). The mycotoxins ochratoxin A (OTA) and fumonisins of the B- and C-series (FB 1 , FB 2 , FB 3 , FB 4 , FC 2/3 , and FC 4 ) as well as partially hydrolyzed fumonisins (pHFB 1 , pHFB 2 , pHFB 3 , pHFC 1 , and pHFC 2/3 ) could successfully be detected by MALDI-IMS in mold-infested foodstuffs. The toxins are distributed differently in the material: OTA is co-localized with visible fungal spoilage while fumonisins could be detected throughout the whole sample. This work shows the applicability of MALDI-Imaging Mass Spectrometry (MALDI-MSI) to mycotoxin analysis. It has been demonstrated that the analyzed mycotoxins are differently distributed within moldy foodstuffs. These findings show the potential of MALDI-MSI for the localization of these hazardous compounds in various plant tissues. This article is protected by copyright. All rights reserved.

Identification of Vitamin D3 Oxidation Products Using High-Resolution and Tandem Mass Spectrometry.

PubMed

Mahmoodani, Fatemeh; Perera, Conrad O; Abernethy, Grant; Fedrizzi, Bruno; Greenwood, David; Chen, Hong

2018-03-19

In a successful fortification program, the stability of micronutrients added to the food is one of the most important factors. The added vitamin D3 is known to sometimes decline during storage of fortified milks, and oxidation through fatty acid lipoxidation could be suspected as the likely cause. Identification of vitamin D3 oxidation products (VDOPs) in natural foods is a challenge due to the low amount of their contents and their possible transformation to other compounds during analysis. The main objective of this study was to find a method to extract VDOPs in simulated whole milk powder and to identify these products using LTQ-ion trap, Q-Exactive Orbitrap and triple quadrupole mass spectrometry. The multistage mass spectrometry (MS n ) spectra can help to propose plausible schemes for unknown compounds and their fragmentations. With the growth of combinatorial libraries, mass spectrometry (MS) has become an important analytical technique because of its speed of analysis, sensitivity, and accuracy. This study was focused on identifying the fragmentation rules for some VDOPs by incorporating MS data with in silico calculated MS fragmentation pathways. Diels-Alder derivatization was used to enhance the sensitivity and selectivity for the VDOPs' identification. Finally, the confirmed PTAD-derivatized target compounds were separated and analyzed using ESI(+)-UHPLC-MS/MS in multiple reaction monitoring (MRM) mode. Graphical Abstract ᅟ.

Identification of Vitamin D3 Oxidation Products Using High-Resolution and Tandem Mass Spectrometry

NASA Astrophysics Data System (ADS)

Mahmoodani, Fatemeh; Perera, Conrad O.; Abernethy, Grant; Fedrizzi, Bruno; Greenwood, David; Chen, Hong

2018-03-01

In a successful fortification program, the stability of micronutrients added to the food is one of the most important factors. The added vitamin D3 is known to sometimes decline during storage of fortified milks, and oxidation through fatty acid lipoxidation could be suspected as the likely cause. Identification of vitamin D3 oxidation products (VDOPs) in natural foods is a challenge due to the low amount of their contents and their possible transformation to other compounds during analysis. The main objective of this study was to find a method to extract VDOPs in simulated whole milk powder and to identify these products using LTQ-ion trap, Q-Exactive Orbitrap and triple quadrupole mass spectrometry. The multistage mass spectrometry (MSn) spectra can help to propose plausible schemes for unknown compounds and their fragmentations. With the growth of combinatorial libraries, mass spectrometry (MS) has become an important analytical technique because of its speed of analysis, sensitivity, and accuracy. This study was focused on identifying the fragmentation rules for some VDOPs by incorporating MS data with in silico calculated MS fragmentation pathways. Diels-Alder derivatization was used to enhance the sensitivity and selectivity for the VDOPs' identification. Finally, the confirmed PTAD-derivatized target compounds were separated and analyzed using ESI(+)-UHPLC-MS/MS in multiple reaction monitoring (MRM) mode. [Figure not available: see fulltext.

Detection of caffeine in tea, instant coffee, green tea beverage, and soft drink by direct analysis in real time (DART) source coupled to single-quadrupole mass spectrometry.

PubMed

Wang, Lei; Zhao, Pengyue; Zhang, Fengzu; Bai, Aijuan; Pan, Canping

2013-01-01

Ambient ionization direct analysis in real time (DART) coupled to single-quadrupole MS (DART-MS) was evaluated for rapid detection of caffeine in commercial samples without chromatographic separation or sample preparation. Four commercial samples were examined: tea, instant coffee, green tea beverage, and soft drink. The response-related parameters were optimized for the DART temperature and MS fragmentor. Under optimal conditions, the molecular ion (M+H)+ was the major ion for identification of caffeine. The results showed that DART-MS is a promising tool for the quick analysis of important marker molecules in commercial samples. Furthermore, this system has demonstrated significant potential for high sample throughput and real-time analysis.

Oil-in-water monitoring using membrane inlet mass spectrometry.

PubMed

Brkić, Boris; France, Neil; Taylor, Stephen

2011-08-15

A membrane inlet mass spectrometry (MIMS) system has been used for detection and analysis of two types of North Sea crude oil. The system was installed on-field on the Flotta Oil Terminal (Orkney, UK). It consisted of a quadrupole mass spectrometer (QMS) connected to the capillary probe with a silicone-based membrane. The produced mass spectra and calibration plots from the MIMS instrument showed the capability to measure levels of individual hydrocarbons within crude oil in seawater. The generated mass spectra from the field tests also showed the ability to distinguish between different types of oil and to determine concentrations of toxic hydrocarbons in oil (e.g., benzene, toluene, and xylene (BTX)). The performance of the instrument at different temperatures of seawater and oil droplet sizes was also investigated. The results showed that the QMS-based MIMS system has a potential to complement existing oil-in-water (OiW) monitors by being able to detect different oil types and specific hydrocarbon concentrations with high accuracy, which are currently not supported in commercially available OiW monitors.

Online Ozonolysis Combined with Ion Mobility-Mass Spectrometry Provides a New Platform for Lipid Isomer Analyses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Poad, Berwyck L. J.; Zheng, Xueyun; Mitchell, Todd W.

One of the most significant challenges in contemporary lipidomics lies in the separation and identification of lipid isomers that differ only in site(s) of unsaturation or geometric configuration of the carbon-carbon double bonds. While analytical separation techniques including ion mobility spectrometry (IMS) and liquid chromatography (LC) can separate isomeric lipids under appropriate conditions, conventional tandem mass spectrometry cannot provide unequivocal identification. To address this challenge, we have implemented ozone-induced dissociation (OzID) in-line with LC, IMS and high resolution mass spectrometry. Modification of an IMS- capable quadrupole time-of-flight mass spectrometer was undertaken to allow the introduction of ozone into the high-pressuremore » trapping ion funnel region preceding the IMS cell. This enabled the novel LC-OzID-IMS-MS configuration where ozonolysis of ionized lipids occurred rapidly (10 ms) without prior mass-selection. LC-elution time alignment combined with accurate mass and arrival time extraction of ozonolysis products facilitated correlation of precursor and product ions without mass-selection (and associated reductions in duty cycle). Unsaturated lipids across 11 classes were examined using this workflow in both positive and negative ion modalities and in all cases the positions of carbon-carbon double bonds were unequivocally assigned based on predictable OzID transitions. Under these conditions geometric isomers exhibited different IMS arrival time distributions and distinct OzID product ion ratios providing a means for discrimination of cis/trans double bonds in complex lipids. The combination of OzID with multidimensional separations shows significant promise for facile profiling of unsaturation patterns within complex lipidomes.« less

Characterization and classification of seven citrus herbs by liquid chromatography-quadrupole time-of-flight mass spectrometry and genetic algorithm optimized support vector machines.

PubMed

Duan, Li; Guo, Long; Liu, Ke; Liu, E-Hu; Li, Ping

2014-04-25

Citrus herbs have been widely used in traditional medicine and cuisine in China and other countries since the ancient time. However, the authentication and quality control of Citrus herbs has always been a challenging task due to their similar morphological characteristics and the diversity of the multi-components existed in the complicated matrix. In the present investigation, we developed a novel strategy to characterize and classify seven Citrus herbs based on chromatographic analysis and chemometric methods. Firstly, the chemical constituents in seven Citrus herbs were globally characterized by liquid chromatography combined with quadrupole time-of-flight mass spectrometry (LC-QTOF-MS). Based on their retention time, UV spectra and MS fragmentation behavior, a total of 75 compounds were identified or tentatively characterized in these herbal medicines. Secondly, a segmental monitoring method based on LC-variable wavelength detection was developed for simultaneous quantification of ten marker compounds in these Citrus herbs. Thirdly, based on the contents of the ten analytes, genetic algorithm optimized support vector machines (GA-SVM) was employed to differentiate and classify the 64 samples covering these seven herbs. The obtained classifier showed good prediction performance and the overall prediction accuracy reached 96.88%. The proposed strategy is expected to provide new insight for authentication and quality control of traditional herbs. Copyright © 2014 Elsevier B.V. All rights reserved.

Rapid simultaneous determination of isoflavones in Radix puerariae using high-performance liquid chromatography-triple quadrupole mass spectrometry with novel shell-type column.

PubMed

Du, Gang; Zhao, Haiyu; Song, Yuelin; Zhang, Qingwen; Wang, Yitao

2011-10-01

A high-performance liquid chromatography (HPLC) coupled with triple quadrupole mass spectrometry (MS/MS) method was developed for rapid determination of 13 isoflavones in Radix puerariae. A novel shell-type column, namely Kinetex core-shell C(18) column (50 mm×2.1 mm id, 2.6 μm), and gradient elution were used during the analysis. The chromatographic peaks of 13 investigated compounds were identified by comparing their retention time and MS data with the related reference compounds. Multiple-reaction monitoring (MRM) was employed for the quantitative analysis with negative ionization mode. All calibration curves showed good linearity (r(2)>0.9990) within test ranges. The LOD and LOQ were lower than 0.017 and 0.873 μg/mL on column, respectively. The intra- and inter-day precisions for 13 analytes were <1.17 and 2.17%, respectively, and the recoveries were 93.1-104.4%. The validated method was applied for quantitative analysis of 13 isoflavones in 7 species of Radix puerariae. The result demonstrated that HPLC-MS/MS system with Kinetex column could be a promising analytical tool for the determination of isoflavones in traditional Chinese medicines, which is helpful for comprehensive evaluation of quality of R. puerariae. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Investigation of the Effect of Rice Wine on the Metabolites of the Main Components of Herbal Medicine in Rat Urine by Ultrahigh-Performance Liquid Chromatography-Quadrupole/Time-of-Flight Mass Spectrometry: A Case Study on Cornus officinalis.

PubMed

Cao, Gang; Cai, Hao; Yue, Xianke; Tu, Sicong; Cai, Baochang; Xu, Zhiwei

2013-01-01

Ultrahigh-performance liquid chromatography-quadrupole/time-of-flight mass spectrometry (UPLC-QTOF/MS) was developed for rapid and sensitive analysis of the effect of rice wine on the metabolites of the main components of herbal medicine in rat urine. Using Cornus officinalis as a model of herbal medicine, the metabolite profiles of crude and processed (steaming the crude drug presteeped in rice wine) Cornus officinalis extracts in rat urine were investigated. The metabolites of Cornus officinalis were identified by using dynamic adjustment of the fragmentor voltage to produce structure-relevant fragment ions. In this work, we identified the parent compounds and metabolites of crude and processed Cornus officinalis in rats. In total, three parent compounds and seventeen new metabolites of Cornus officinalis were found in rats. The contents of the parent compounds and metabolites in vivo varied significantly after intragastric (i.g.) administration of aqueous extracts of crude and processed Cornus officinalis. Data from this study suggests that UPLC-QTOF/MS could be used as a potential tool for uncovering the effects of excipients found in the metabolites of the main components of herbal medicine, in vivo, to predict and discover the processing mechanisms of herbal medicine.

Systematic chemical profiling of Citrus grandis 'Tomentosa' by ultra-fast liquid chromatography/diode-array detector/quadrupole time-of-flight tandem mass spectrometry.

PubMed

Li, Pan-lin; Liu, Meng-hua; Hu, Jie-hui; Su, Wei-wei

2014-03-01

Citrus grandis 'Tomentosa', as the original plant of the traditional Chinese medicine "Huajuhong", has been used as antitussive and expectorant in clinic for thousands of years. The fruit epicarp and whole fruit of this plant were both literarily recorded and commonly used. In the present study, an ultra-fast liquid chromatography coupled with diode-array detection and quadrupole/time-of-flight mass spectrometry (UFLC-DAD-Q-TOF-MS/MS) based chemical profiling method was developed for rapid holistic quality evaluation of C. grandis 'Tomentosa', which laid basis for chemical comparison of two medicinal parts. As a result, forty-eight constituents, mainly belonging to flavonoids and coumarins, were unambiguously identified by comparison with reference standards and/or tentatively characterized by elucidating UV spectra, quasi-molecular ions and fragment ions referring to information available in literature. Both of the epicarp and whole fruit samples were rich in flavonoids and coumarins, but major flavonoids contents in whole fruit were significantly higher than in epicarp (P<0.5). The proposed method could be useful in quality control and standardization of C. grandis 'Tomentosa' raw materials and its products. Results obtained in this study will provide a basis for quality assessment and further study in vivo. Copyright © 2013 Elsevier B.V. All rights reserved.

Quantification and semiquantification of multiple representative components for the holistic quality control of Allii Macrostemonis Bulbus by ultra high performance liquid chromatography with quadrupole time-of-flight tandem mass spectrometry.

PubMed

Qin, Zifei; Lin, Pei; Dai, Yi; Yao, Zhihong; Wang, Li; Yao, Xinsheng; Liu, Liyin; Chen, Haifeng

2016-05-01

Allii Macrostemonis Bulbus (named Xiebai in China) is a folk medicine with medicinal values for the treatment of thoracic obstruction and cardialgia, and a food additive as well. However, there is even no quantitative standard for Allii Macrostemonis Bulbus recorded in the current edition of the Chinese Pharmacopeia. Hence, simultaneous assay of multiple components is urgent. In this study, chemometric methods were firstly applied to discover the components with significant fluctuation among multiple Allii Macrostemonis Bulbus samples based on optimized fingerprints. Meanwhile, the major components and main absorbed components in rats were all selected as its representative components. Subsequently, a sensitive method was established for the simultaneous determination of 54 components (15 components for quantification and 39 components for semiquantification) by ultra high performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry. Moreover, the validated method was successfully applied to evaluate the quality of multiple samples on the market. It became known that multiple Allii Macrostemonis Bulbus samples varied significantly and showed poor consistency. This work illustrated that the proposed approach could improve the quality of Allii Macrostemonis Bulbus, and it also provided a feasible method for quality evaluation of other traditional Chinese medicines. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Identification of compounds in an anti-fibrosis Chinese medicine (Fufang Biejia Ruangan Pill) and its absorbed components in rat biofluids and liver by UPLC-MS.

PubMed

Dong, Qin; Qiu, Ling-Ling; Zhang, Cong-En; Chen, Long-Hu; Feng, Wu-Wen; Ma, Li-Na; Yan, Dan; Niu, Ming; Wang, Jia-Bo; Xiao, Xiao-He

2016-07-15

Liver fibrosis represents a major public health problem worldwide. To date, antifibrotic treatment of fibrosis still remains an unconquered area for western medicine. Fufang Biejia Ruangan Pill (FFBJ) is the first anti-fibrosis drug approved by the China State Food and Drug Administration, and has been demonstrated to have a good antifibrotic efficacy in China. However, the chemical constituents of FFBJ and the absorption and distribution of it in vivo remain unclear, which restricts its research on bioactive components identification and mechanisms of action. In this study, ultra-performance liquid chromatography/quadrupole-time-of-flight mass spectrometry (UPLC/Q-TOF-MS) combined with ultra-performance liquid chromatography/triple quadrupole mass spectrometry (UPLC/QqQ-MS) was applied to identify compounds in FFBJ and its absorbed components in rat serum, liver and urine samples after intragastric administration of FFBJ. As a result, a total of 32 Chinese material medica components including organic acids, terpenoids, flavonoids, phenylpropanoids and alkaloids, were identified or tentatively characterized, while the distribution of 10 prototype compounds in rat serum, liver and urine were discovered. The identified constituents in FFBJ and the distribution of prototype compounds in rat serum, liver and urine are help for understanding the material bases of its therapeutic effects. Copyright © 2016. Published by Elsevier B.V.

Ultra performance liquid chromatography/quadrupole-time-of-flight mass spectrometry for determination of avicularin metabolites produced by a human intestinal bacterium.

PubMed

Zhao, Min; Xu, Jun; Qian, Dawei; Guo, Jianming; Jiang, Shu; Shang, Er-xin; Duan, Jin-ao; Yang, Jing; Du, Le-yue

2014-02-15

Intestinal bacteria from human were screened to isolate the specific bacteria involved in the metabolism of avicularin. A Gram-positive anaerobic bacterium, strain 46, capable of metabolizing avicularin (quercetin-3-O-arabinoside) was isolated for the first time. Its 16S rRNA gene sequence showed 99% similarity with that of Bacillus. Then strain 46 was identified as a species of the genus Bacillus, and was named to be Bacillus sp. 46. Additionally, the metabolites were analyzed by ultra performance liquid chromatography/quadrupole-time-of-flight mass spectrometry (UPLC/Q-TOF-MS) technique combined with Metabolynx™ software. The structure of these metabolites were proposed and confirmed by comparing the UPLC retention time and MS/MS spectrum with that of authentic standards. Parent compound and six metabolites were detected in the isolated bacterial samples compared with blank samples. Avicularin (M1) was anaerobic metabolized to its aglycone quercetin (M2) and methoxylated avicularin (M3, M4), then quercetin was converted to quercetin glycosides: quercetin-3-O-rhamnoside (M5), quercetin-3-O-glucoside (M6) and quercetin-7-O-glucoside (M7) by Bacillus sp. 46. The metabolic pathway and metabolites of avicularin by the intestinal bacterium Bacillus sp. 46 were reported for the first time. Copyright © 2014 Elsevier B.V. All rights reserved.

Multi-ingredients determination and fingerprint analysis of leaves from Ilex latifolia using ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry.

PubMed

Fan, Chunlin; Deng, Jiewei; Yang, Yunyun; Liu, Junshan; Wang, Ying; Zhang, Xiaoqi; Fai, Kuokchiu; Zhang, Qingwen; Ye, Wencai

2013-10-01

An ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) method integrating multi-ingredients determination and fingerprint analysis has been established for quality assessment and control of leaves from Ilex latifolia. The method possesses the advantages of speediness, efficiency, accuracy, and allows the multi-ingredients determination and fingerprint analysis in one chromatographic run within 13min. Multi-ingredients determination was performed based on the extracted ion chromatograms of the exact pseudo-molecular ions (with a 0.01Da window), and fingerprint analysis was performed based on the base peak chromatograms, obtained by negative-ion electrospray ionization QTOF-MS. The method validation results demonstrated our developed method possessing desirable specificity, linearity, precision and accuracy. The method was utilized to analyze 22 I. latifolia samples from different origins. The quality assessment was achieved by using both similarity analysis (SA) and principal component analysis (PCA), and the results from SA were consistent with those from PCA. Our experimental results demonstrate that the strategy integrated multi-ingredients determination and fingerprint analysis using UPLC-QTOF-MS technique is a useful approach for rapid pharmaceutical analysis, with promising prospects for the differentiation of origin, the determination of authenticity, and the overall quality assessment of herbal medicines. Copyright © 2013 Elsevier B.V. All rights reserved.

Characterization of the multiple components of Acanthopanax Senticosus stem by ultra high performance liquid chromatography with quadrupole time-of-flight tandem mass spectrometry.

PubMed

Sun, Hui; Liu, Jianhua; Zhang, Aihua; Zhang, Ying; Meng, Xiangcai; Han, Ying; Zhang, Yingzhi; Wang, Xijun

2016-02-01

Acanthopanax Senticosus Harms. has been used widely in traditional Chinese medicine for the treatment of chronic bronchitis, neurasthenia, hypertension and ischemic heart disease. However, the in vivo constituents of the stem of Acanthopanax Senticosus remain unknown. In this paper, ultra high performance liquid chromatography with electrospray ionization quadrupole time-of-flight mass spectrometry and the MarkerLynx(TM) software combined with multiple data processing approach were used to study the constituents in vitro and in vivo. The aqueous extract from the Acanthopanax Senticosus stem and the compositions in rat serum after intragastric administration were completely analyzed. Consequently, 115 compounds in the aqueous extract from Acanthopanax Senticosus stem and 41 compounds absorbed into blood were characterized. Of the 115 compounds in vitro, 54 were reported for first time, including sinapyl alcohol, sinapyl alcohol diglucoside, and 1-O-sinapoyl-β-D-glucose. In the 41 compounds in vivo, 7 were prototype components and 34 were metabolites which were from 21 components of aqueous extract from Acanthopanax Senticosus stem, and the metabolic pathways of the metabolites were elucidated for first time. The results narrowed the range of screening the active components and provided a basis for the study of action mechanism and pharmacology. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Comparison of Chemical Constituents in Scrophulariae Radix Processed by Different Methods based on UFLC-MS Combined with Multivariate Statistical Analysis.

PubMed

Wang, Shengnan; Hua, Yujiao; Zou, Lisi; Liu, Xunhong; Yan, Ying; Zhao, Hui; Luo, Yiyuan; Liu, Juanxiu

2018-02-01

Scrophulariae Radix is one of the most popular traditional Chinese medicines (TCMs). Primary processing of Scrophulariae Radix is an important link which closely related to the quality of products in this TCM. The aim of this study is to explore the influence of different processing methods on chemical constituents in Scrophulariae Radix. The difference of chemical constituents in Scrophulariae Radix processed by different methods was analyzed by using ultra fast liquid chromatography-triple quadrupole-time of flight mass spectrometry coupled with principal component analysis and orthogonal partial least squares discriminant analysis. Furthermore, the contents of 12 index differential constituents in Scrophulariae Radix processed by different methods were simultaneously determined by using ultra fast liquid chromatography coupled with triple quadrupole-linear ion trap mass spectrometry. Gray relational analysis was performed to evaluate the different processed samples according to the contents of 12 constituents. All of the results demonstrated that the quality of Scrophulariae Radix processed by "sweating" method was better. This study will provide the basic information for revealing the change law of chemical constituents in Scrophulariae Radix processed by different methods and facilitating selection of the suitable processing method of this TCM. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Innovative analytical method for the determination of underivatized tributyltin and pentachlorophenol in seawater by gas chromatography-triple quadrupole mass spectrometry.

PubMed

Amendola, Luca; Cortese, Maria; Vinatoru, Daniela; Sposato, Silvana; Insogna, Susanna

2017-07-04

Tributyltin (TBT) and pentachlorophenol (PCP) are listed as priority substances that warrant monitoring in the European Water Framework Directive (WFD 2000/60/CE), since TBT and PCP were identified as environmental endocrine disruptors and exhibit considerable toxicity toward both aquatic organisms and mammals even at very low levels. This paper shows a novel approach to analyze underivatized tributyltin (TBT) and pentachlorophenol (PCP) in seawater based on capillary gas chromatography-triple quadrupole mass spectrometry. The optimized extraction method for TBT an PCP in water involved liquid-liquid microextraction with toluene. The reduced extract was added with a solvent mix, composed of methanol and trimethylsilyl derivatives of methanol (MeOTMS), that allowed good chromatographic resolution of underivatized TBT and PCP, interacting as a lubricant along the glass liner during the injection phase. The proposed method showed good linearity and repeatability (RSD%<20% at 0.05 ng L -1 for TBT and 0.2 μg L -1 for PCP). The overall recoveries were 74% and 106% for TBT and PCP, respectively. Very low quantification limits that met the strict statutory and regulatory demands were achieved: 0.002 ng L -1 for TBT and 0.050 μg L -1 for PCP. Copyright © 2017 Elsevier B.V. All rights reserved.

Simultaneous Quantification of 11 Constituents in Wuji Pill Using Ultra Performance Liquid Chromatography Coupled With a Triple Quadrupole Electrospray Tandem Mass Spectrometry.

PubMed

Tian, Tingting; Jin, Yiran; Ma, Yinghua; Xie, Weiwei; Xu, Huijun; Du, Yingfeng

2016-02-01

An ultra performance liquid chromatography coupled with a triple quadrupole electrospray tandem mass spectrometry (UPLC-MS-MS) method was developed for analyzing and identifying the constituents of 11 compounds including berberine, epiberberine, berberrubine, jatrorrhizine, coptisine, palmatine, evodiamine, rutaecarpine, limonin, paeoniflorin and albiflorin in Wuji pill (WJ pill), a traditional Chinese medicine. The chromatographic separation was performed on a C18 column and the mobile phase was composed of water (0.1% formic acid and 2 mmol ammonium acetate) and methanol with a linear gradient elution. The detection was performed by multiple reaction monitoring mode, using electrospray ionization in the positive ion mode. The total run time was 14 min. The calibration curves were linear with all correlation coefficients higher than 0.9987 in the tested range. The intra- and interday precisions were no more than 4.9%, and the average recoveries were from 92.4 to 107.8% with the relative standard deviations no more than 7.8%. The developed method was successfully employed to analyze five batches of WJ pill samples. This is the first time to establish a method for the quality control of WJ pill to ensure the safety and efficacy in clinical applications effectively. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Progress in mass spectrometry for the analysis of set-off phenomena in plastic food packaging materials.

PubMed

Aznar, Margarita; Alfaro, Pilar; Nerín, Cristina; Jones, Emrys; Riches, Eleanor

2016-07-01

In most cases, food packaging materials contain inks whose components can migrate to food by diffusion through the material as well as by set-off phenomena. In this work, different mass spectrometry approaches had been used in order to identify and confirm the presence of ink components in ethanol (95%) and Tenax(®) as food simulants. Three different sets of materials, manufactured with different printing technologies and with different structures, were analyzed. Sample analysis by ultra performance liquid chromatography mass spectrometry (UPLC-MS), using a quadrupole-time of flight (Q-TOF) as a mass analyser proved to be an excellent tool for identification purposes while ion mobility mass spectrometry (IM-MS) shown to be very useful for the confirmation of the candidates proposed. The results showed the presence of different non-volatile ink components in migration such as colorants (Solvent Red 49), plasticizers (dimethyl sebacate, tributyl o-acetyl citrate) or surfactants (SchercodineM, triethylene glycol caprilate). An oxidation product of an ink additive (triphenyl phosphine oxide) was also detected. In addition, a surface analysis technique, desorption electrospray mass spectrometry (DESI-MS), was used for analyzing the distribution of some ink components (tributyl o-acetyl citrate Schercodine L, phthalates) in the material. The detection of some of these compounds in the back-printed side confirmed the transference of this compound from the non-food to the food contact side. The results also showed that concentration of ink migrants decreased when an aluminum or polypropylene layer covered the ink. When aluminum was used, concentration of most of ink migrants decreased, and for 5 out of the 9 even disappeared. Copyright © 2016 Elsevier B.V. All rights reserved.

Cluster reactivity experiments: Employing mass spectrometry to investigate the molecular level details of catalytic oxidation reactions

PubMed Central

Johnson, Grant E.; Tyo, Eric C.; Castleman, A. W.

2008-01-01

Mass spectrometry is the most widely used tool in the study of the properties and reactivity of clusters in the gas phase. In this article, we demonstrate its use in investigating the molecular-level details of oxidation reactions occurring on the surfaces of heterogeneous catalysts via cluster reactivity experiments. Guided ion beam mass spectrometry (GIB-MS) employing a quadrupole–octopole–quadrupole (Q–O–Q) configuration enables mass-selected cluster ions to be reacted with various chemicals, providing insight into the effect of size, stoichiometry, and ionic charge state on the reactivity of catalyst materials. For positively charged tungsten oxide clusters, it is shown that species having the same stoichiometry as the bulk, WO3+, W2O6+, and W3O9+, exhibit enhanced activity and selectivity for the transfer of a single oxygen atom to propylene (C3H6), suggesting the formation of propylene oxide (C3H6O), an important monomer used, for example, in the industrial production of plastics. Furthermore, the same stoichiometric clusters are demonstrated to be active for the oxidation of CO to CO2, a reaction of significance to environmental pollution abatement. The findings reported herein suggest that the enhanced oxidation reactivity of these stoichiometric clusters may be due to the presence of radical oxygen centers (W–O●) with elongated metal–oxygen bonds. The unique insights gained into bulk-phase oxidation catalysis through the application of mass spectrometry to cluster reactivity experiments are discussed. PMID:18687883

The Combustion Experiment on the Sample Analysis at Mars (SAM) Instrument Suite on the Curiosity Rover

NASA Technical Reports Server (NTRS)

Stern, J. C.; Malespin, C. A.; Eigenbrode, J.; Graham, H. V.; Archer, P. D.; Brunner, A.; Freissinet, C.; Franz, H. B.; Fuentes, J.; Glavin, D. P.;

Re-investigation of the fragmentation of protonated carotenoids by electrospray ionization and nanospray tandem mass spectrometry.

PubMed

Neto, Fausto Carnevale; Guaratini, Thais; Costa-Lotufo, Letícia; Colepicolo, Pio; Gates, Paul J; Lopes, Norberto Peporine

2016-07-15

Carotenoids are polyene isoprenoids with an important role in photosynthesis and photoprotection. Their characterization in biological matrices is a crucial subject for biochemical research. In this work we report the full fragmentation of 16 polyenes (carotenes and xanthophylls) by electrospray ionization tandem mass spectrometry (ESI-CID-MS/MS) and nanospray tandem mass spectrometry (nanoESI-CID-MS/MS). Analyses were carried out on a quadrupole time-of-flight (QTOF) mass spectrometer coupled with a nanoESI source and on a Fourier transform ion cyclotron resonance (FTICR) mass spectrometer with an ESI source. The formulae of the product ions were determined by accurate-mass measurements. It is demonstrated that the fragmentation routes observed for the protonated carotenoids derive essentially from charge-remote fragmentations and pericyclic rearrangements, such as electrocyclic and retro-ene eliminations (assisted or not by a sigmatropic hydrogen shift). All mechanisms are dependent on cis-trans isomerization through the formation of several conjugated polyene carbocation intermediates. Some specific ions for the carotenoid epoxides were justified through formation of cyclic oxonium ions. Complete fragmentation pathways of protonated carotenoids by ESI- and nanoESI-CID-MS/MS provided structural information about functional groups, polyene chain and double bonds, and contribute to identification of carotenoids based on MS/MS fragmentation patterns. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Proteomics: from hypothesis to quantitative assay on a single platform. Guidelines for developing MRM assays using ion trap mass spectrometers.

PubMed

Han, Bomie; Higgs, Richard E

2008-09-01

High-throughput HPLC-mass spectrometry (HPLC-MS) is routinely used to profile biological samples for potential protein markers of disease, drug efficacy and toxicity. The discovery technology has advanced to the point where translating hypotheses from proteomic profiling studies into clinical use is the bottleneck to realizing the full potential of these approaches. The first step in this translation is the development and analytical validation of a higher throughput assay with improved sensitivity and selectivity relative to typical profiling assays. Multiple reaction monitoring (MRM) assays are an attractive approach for this stage of biomarker development given their improved sensitivity and specificity, the speed at which the assays can be developed and the quantitative nature of the assay. While the profiling assays are performed with ion trap mass spectrometers, MRM assays are traditionally developed in quadrupole-based mass spectrometers. Development of MRM assays from the same instrument used in the profiling analysis enables a seamless and rapid transition from hypothesis generation to validation. This report provides guidelines for rapidly developing an MRM assay using the same mass spectrometry platform used for profiling experiments (typically ion traps) and reviews methodological and analytical validation considerations. The analytical validation guidelines presented are drawn from existing practices on immunological assays and are applicable to any mass spectrometry platform technology.

Electron impact action spectroscopy of mass/charge selected macromolecular ions: Inner-shell excitation of ubiquitin protein

NASA Astrophysics Data System (ADS)

Ranković, Miloš Lj.; Giuliani, Alexandre; Milosavljević, Aleksandar R.

2016-02-01

We have performed inner-shell electron impact action spectroscopy of mass and charge selected macromolecular ions. For this purpose, we have coupled a focusing electron gun with a linear quadrupole ion trap mass spectrometer. This experiment represents a proof of principle that an energy-tunable electron beam can be used in combination with radio frequency traps as an activation method in tandem mass spectrometry (MS2) and allows performing action spectroscopy. Electron impact MS2 spectra of multiply protonated ubiquitin protein ion have been recorded at incident electron energies around the carbon 1 s excitation. Both MS2 and single ionization energy dependence spectra are compared with literature data obtained using the soft X-ray activation conditions.

Dioxin analysis by gas chromatography-Fourier transform ion cyclotron resonance mass spectrometry (GC-FTICRMS).

PubMed

Taguchi, Vince Y; Nieckarz, Robert J; Clement, Ray E; Krolik, Stefan; Williams, Robert

2010-11-01

The feasibility of utilizing a gas chromatograph-tandem quadrupole-Fourier transform ion cyclotron resonance mass spectrometer (GC-MS/MS-FTICRMS) to analyze chlorinated-dioxins/furans (CDDs/CDFs) and mixed halogenated dioxins/furans (HDDs/HDFs) was investigated by operating the system in the GC-FTICRMS mode. CDDs/CDFs and mixed HDDs/HDFs could be analyzed at 50,000 to 100,000 resolving power (RP) on the capillary gas chromatographic time scale. Initial experiments demonstrated that 1 pg of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and 5 pg of 2-bromo-3,7,8-trichlorodibenzo-p-dioxin (BTrCDD) could be detected. The feasibility of utilizing an FTICRMS for screening of CDDs/CDFs, HDDs/HDFs and related compounds was also investigated by analyzing an extract from vegetation exposed to fall-out from an industrial fire. CDDs/CDFs, chlorinated pyrenes and chlorinated tetracenes could be detected from a Kendrick plot analysis of the ultrahigh resolution mass spectra. Mass accuracies were of the order of 0.5 ppm on standards with external mass calibration and 1 ppm on a sample with internal mass calibration. Copyright © 2010 American Society for Mass Spectrometry. Published by Elsevier Inc. All rights reserved.

A history of mass spectrometry in Australia.

PubMed

Downard, Kevin M; de Laeter, John R

2005-09-01

An interest in mass spectrometry in Australia can be traced back to the 1920s with an early correspondence with Francis Aston who first visited these shores a decade earlier. The region has a rich tradition in both the development of the field and its application, from early measurements of ionization and appearance potentials by Jim Morrison at the Council for Scientific and Industrial Research (CSIR) around 1950 to the design and construction of instrumentation including the first use of a triple quadrupole mass spectrometer for tandem mass spectrometry, the first suite of programs to simulate ion optics (SIMION), the development of early TOF/TOF instruments and orthogonal acceleration and the local design and construction of several generations of a sensitive high-resolution ion microprobe (SHRIMP) instrument. Mass spectrometry has been exploited in the study and characterization of the constituents of this nation's unique flora and fauna from Australian apples, honey, tea plant and eucalyptus oil, snake, spider, fish and frog venoms, coal, oil, sediments and shale, environmental studies of groundwater to geochronological dating of limestone and granite, other terrestrial and meteoritic rocks and coral from the Great Barrier Reef. Peter Jeffery's establishment of geochronological dating techniques in Western Australia in the early 1950s led to the establishment of geochronology research both at the Australian National University and at what is now the Curtin Institute of Technology in the 1960s. This article traces the history of mass spectrometry in its many guises and applications in the island continent of Australia. An article such as this can never be complete. It instead focuses on contributions of scientists who played a major role in the early establishment of mass spectrometry in Australia. In general, those who are presently active in the field, and whose histories are incomplete, have been mentioned at best only briefly despite their important contributions to the field.

Determination of trichloroanisole and trichlorophenol in wineries' ambient air by passive sampling and thermal desorption-gas chromatography coupled to tandem mass spectrometry.

PubMed

Camino-Sánchez, F J; Bermúdez-Peinado, R; Zafra-Gómez, A; Ruíz-García, J; Vílchez-Quero, J L

2015-02-06

The present paper describes the calibration of selected passive samplers used in the quantitation of trichlorophenol and trichloroanisole in wineries' ambient air, by calculating the corresponding sampling rates. The method is based on passive sampling with sorbent tubes and involves thermal desorption-gas chromatography-triple quadrupole mass spectrometry analysis. Three commercially available sorbents were tested using sampling cartridges with a radial design instead of axial ones. The best results were found for Tenax TA™. Sampling rates (R-values) for the selected sorbents were determined. Passive sampling was also used for accurately determining the amount of compounds present in the air. Adequate correlation coefficients between the mass of the target analytes and exposure time were obtained. The proposed validated method is a useful tool for the early detection of trichloroanisole and its precursor trichlorophenol in wineries' ambient air while avoiding contamination of wine or winery facilities. Copyright © 2015 Elsevier B.V. All rights reserved.

Simultaneous screening for 238 drugs in blood by liquid chromatography-ion spray tandem mass spectrometry with multiple-reaction monitoring.

PubMed

Gergov, M; Ojanperä, I; Vuori, E

2003-09-25

A liquid chromatography-tandem mass spectrometry (LC-MS-MS) method is presented for the qualitative screening for 238 drugs in blood samples, which is considerably more than in previous methods. After a two-step liquid-liquid extraction and C(18) chromatography, the compounds were introduced into a triple quadrupole mass spectrometer equipped with a turbo ion spray ion source operating in the positive ionization mode. Identification was based on the compound's absolute retention time, protonated molecular ion, and one representative fragment ion obtained by multiple reaction monitoring (MRM) at an individually selected collision energy of 20, 35, or 50 eV. The limit of detection (LOD) for the majority of the compounds (80%) was < or = 0.05 mg/l, ranging from 0.002 mg/l (e.g., antihistamines) to 5 mg/l (acidic compounds), and for malathion it was 10 mg/l. The LOD values were sufficiently low to allow the majority of compounds to be detected at therapeutic concentrations in the blood.

Liquid chromatography tandem mass spectrometry assay to determine the pharmacokinetics of aildenafil in human plasma.

PubMed

Wang, Jiang; Jiang, Yao; Wang, Yingwu; Zhao, Xia; Cui, Yimin; Gu, Jingkai

2007-05-09

A simple, sensitive and specific liquid chromatography/tandem mass spectrometry method for the quantitation of aildenafil, a new phosphodiesterase V inhibitor, in human plasma is presented. The analyte and internal standard, sildenafil, were extracted by a one-step liquid-liquid extraction in alkaline conditions and separated on a C(18) column using ammonia:10mM ammonium acetate buffer:methanol (0.1:15:85, v/v/v) as the mobile phase. The detection by an API 4000 triple quadrupole mass spectrometer in multiple-reaction monitoring mode was completed within 2.5 min. The calibration curve exhibited a linear dynamic range of 0.05-100 ng/ml with a 10 pg/ml limit of detection. The intra- and inter-day precisions measured as relative standard deviation were within 8.04% and 5.72%, respectively. This method has been used in a pharmacokinetic study of aildenafil in healthy male volunteers each given an oral administration of one of the three dosages.

Analysis of additives in dairy products by liquid chromatography coupled to quadrupole-orbitrap mass spectrometry.

PubMed

Jia, Wei; Ling, Yun; Lin, Yuanhui; Chang, James; Chu, Xiaogang

2014-04-04

A new method combining QuEChERS with ultrahigh-performance liquid chromatography and electrospray ionization quadrupole Orbitrap high-resolution mass spectrometry (UHPLC/ESI Q-Orbitrap) was developed for the highly accurate and sensitive screening of 43 antioxidants, preservatives and synthetic sweeteners in dairy products. Response surface methodology was employed to optimize a quick, easy, cheap, effective, rugged, and safe (QuEChERS) sample preparation method for the determination of 42 different analytes in dairy products for the first time. After optimization, the maximum predicted recovery was 99.33% rate for aspartame under the optimized conditions of 10 mL acetionitrile, 1.52 g sodium acetate, 410 mg PSA and 404 mgC18. For the matrices studied, the recovery rates of the other 42 compounds ranged from 89.4% to 108.2%, with coefficient of variation <6.4%. UHPLC/ESI Q-Orbitrap Mass full scan mode acquired full MS data was used to identify and quantify additives, and data-dependent scan mode obtained fragment ion spectra for confirmation. The mass accuracy typically obtained is routinely better than 1.5ppm, and only need to calibrate once a week. The 43 compounds behave dynamic in the range 0.001-1000 μg kg(-1) concentration, with correlation coefficient >0.999. The limits of detection for the analytes are in the range 0.0001-3.6 μg kg(-1). This method has been successfully applied on screening of antioxidants, preservatives and synthetic sweeteners in commercial dairy product samples, and it is very useful for fast screening of different food additives. Copyright © 2014 Elsevier B.V. All rights reserved.

Quantitative analysis of veterinary drugs in bovine muscle and milk by liquid chromatography quadrupole time-of-flight mass spectrometry.

PubMed

Saito-Shida, Shizuka; Sakai, Takatoshi; Nemoto, Satoru; Akiyama, Hiroshi

2017-07-01

A simple and reliable multiresidue method for quantitative determination of veterinary drugs in bovine muscle and milk using liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QTOF-MS) was developed. Critical MS parameters such as capillary voltage, cone voltage, collision energy, desolvation gas temperature and extraction mass window were carefully optimised to obtain the best possible sensitivity. Analytical samples were prepared using extraction with acetonitrile and hexane in the presence of anhydrous sodium sulphate and acetic acid, followed by ODS cartridge clean-up. The developed method was validated for 82 veterinary drugs in bovine muscle and milk at spike levels of 0.01 and 0.1 mg kg - 1 . With the exception of cefoperazone and phenoxymethylpenicillin, all these compounds exhibited sufficient signal intensity at 0.01 μg ml -1 (equivalent to 0.01 mg kg - 1 ), indicating the high sensitivity of the developed method. For most targets, the determined accuracies were within 70-120%, with repeatability and reproducibility being below 20% at both levels. Except for sulfathiazole in bovine muscle, no interfering peaks at target compound retention times were detected in the blank extract, indicating that the developed method is highly selective. The absence of sulfathiazole in bovine muscle was confirmed by simultaneous acquisition at low and high collision energies to afford exact masses of molecular adduct and fragment ions. Satisfactory linearity was observed for all compounds, with matrix effects being negligible for most targets in bovine muscle and milk at both spike levels. Overall, the results suggest that the developed LC-QTOF-MS method is suitable for routine regulatory-purpose analysis of veterinary drugs in bovine muscle and milk.

Simultaneous detection and identification of precursors, degradation and co-products of chemical warfare agents in drinking water by ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry.

PubMed

Tak, Vijay; Purohit, Ajay; Pardasani, Deepak; Goud, D Raghavender; Jain, Rajeev; Dubey, D K

2014-11-28

Environmental markers of chemical warfare agents (CWAs) comprise millions of chemical structures. The simultaneous detection and identification of these environmental markers poses difficulty due to their diverse chemical properties. In this work, by using ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-QTOF), a generic analytical method for the detection and identification of wide range of environmental markers of CWAs (including precursors, degradation and co-products of nerve agents and sesqui-mustards) in drinking water, was developed. The chromatographic analysis of 55 environmental markers of CWAs including isomeric and isobaric compounds was accomplished within 20 min, using 1.8 μm particle size column. Subsequent identification of the compounds was achieved by the accurate mass measurement of either protonated molecule [M+H](+) or ammonium adduct [M+NH4](+) and fragment ions. Isomeric and isobaric compounds were distinguished by chromatographic retention time, characteristic fragment ions generated by both in-source collision induced dissociation (CID) and CID in the collision cell by MS/MS experiments. The exact mass measurement errors for all ions were observed less than 3 ppm with internal calibration. The method limits of detection (LODs) and limits of quantification (LOQs) were determined in drinking water and found to be 1-50 ng mL(-1) and 5-125 ng mL(-1), respectively. Applicability of the proposed method was proved by determining the environmental markers of CWAs in aqueous samples provided by Organization for the Prohibition of Chemical Weapons during 34th official proficiency test. Copyright © 2014 Elsevier B.V. All rights reserved.

Comparison of veterinary drug residue results in animal tissues by ultrahigh-performance liquid chromatography coupled to triple quadrupole or quadrupole-time-of-flight tandem mass spectrometry after different sample preparation methods, including use of a commercial lipid removal product.

PubMed

Anumol, Tarun; Lehotay, Steven J; Stevens, Joan; Zweigenbaum, Jerry

2017-04-01

Veterinary drug residues in animal-derived foods must be monitored to ensure food safety, verify proper veterinary practices, enforce legal limits in domestic and imported foods, and for other purposes. A common goal in drug residue analysis in foods is to achieve acceptable monitoring results for as many analytes as possible, with higher priority given to the drugs of most concern, in an efficient and robust manner. The U.S. Department of Agriculture has implemented a multiclass, multi-residue method based on sample preparation using dispersive solid phase extraction (d-SPE) for cleanup and ultrahigh-performance liquid chromatography-tandem quadrupole mass spectrometry (UHPLC-QQQ) for analysis of >120 drugs at regulatory levels of concern in animal tissues. Recently, a new cleanup product called "enhanced matrix removal for lipids" (EMR-L) was commercially introduced that used a unique chemical mechanism to remove lipids from extracts. Furthermore, high-resolution quadrupole-time-of-flight (Q/TOF) for (U)HPLC detection often yields higher selectivity than targeted QQQ analyzers while allowing retroactive processing of samples for other contaminants. In this study, the use of both d-SPE and EMR-L sample preparation and UHPLC-QQQ and UHPLC-Q/TOF analysis methods for shared spiked samples of bovine muscle, kidney, and liver was compared. The results showed that the EMR-L method provided cleaner extracts overall and improved results for several anthelmintics and tranquilizers compared to the d-SPE method, but the EMR-L method gave lower recoveries for certain β-lactam antibiotics. QQQ vs. Q/TOF detection showed similar mixed performance advantages depending on analytes and matrix interferences, with an advantage to Q/TOF for greater possible analytical scope and non-targeted data collection. Either combination of approaches may be used to meet monitoring purposes, with an edge in efficiency to d-SPE, but greater instrument robustness and less matrix effects when analyzing EMR-L extracts. Graphical abstract Comparison of cleanup methods in the analysis of veterinary drug residues in bovine tissues.

Profiling analysis of low molecular weight heparins by multiple heart-cutting two dimensional chromatography with quadruple time-of-flight mass spectrometry.

PubMed

Ouyang, Yilan; Zeng, Yangyang; Rong, Yinxiu; Song, Yue; Shi, Lv; Chen, Bo; Yang, Xinlei; Xu, Naiyu; Linhardt, Robert J; Zhang, Zhenqing

2015-09-01

Low molecular weight heparins (LMWHs) are polydisperse and microheterogenous mixtures of polysaccharides used as anticoagulant drugs. Profiling analysis is important for obtaining deeper insights into the structure of LMWHs. Previous oligosaccharide mapping methods are relatively low resolution and are unable to show an entire picture of the structural complexity of LMWHs. In the current study a profiling method was developed relying on multiple heart-cutting, two-dimensional, ultrahigh performance liquid chromatography with quadruple time-of-flight mass spectrometry. This represents an efficient, automated, and robust approach for profiling LMWHs. Using size-exclusion chromatography and ion-pairing reversed-phase chromatography in a two-dimensional separation, LMW components of different sizes and LMW components of the same size but with different charges and polarities can be resolved, providing a more complete picture of a LMWH. Structural information on each component was then obtained with quadrupole time-of-flight mass spectrometry. More than 80 and 120 oligosaccharides were observed and unambiguously assigned from the LMWHs, nadroparin and enoxaparin, respectively. This method might be useful for quality control of LMWHs and as a powerful tool for heparin-related glycomics.

Comparison of Atmospheric Pressure Chemical Ionization and Field Ionization Mass Spectrometry for the Analysis of Large Saturated Hydrocarbons.

PubMed

Jin, Chunfen; Viidanoja, Jyrki; Li, Mingzhe; Zhang, Yuyang; Ikonen, Elias; Root, Andrew; Romanczyk, Mark; Manheim, Jeremy; Dziekonski, Eric; Kenttämaa, Hilkka I

2016-11-01

Direct infusion atmospheric pressure chemical ionization mass spectrometry (APCI-MS) was compared to field ionization mass spectrometry (FI-MS) for the determination of hydrocarbon class distributions in lubricant base oils. When positive ion mode APCI with oxygen as the ion source gas was employed to ionize saturated hydrocarbon model compounds (M) in hexane, only stable [M - H] + ions were produced. Ion-molecule reaction studies performed in a linear quadrupole ion trap suggested that fragment ions of ionized hexane can ionize saturated hydrocarbons via hydride abstraction with minimal fragmentation. Hence, APCI-MS shows potential as an alternative of FI-MS in lubricant base oil analysis. Indeed, the APCI-MS method gave similar average molecular weights and hydrocarbon class distributions as FI-MS for three lubricant base oils. However, the reproducibility of APCI-MS method was found to be substantially better than for FI-MS. The paraffinic content determined using the APCI-MS and FI-MS methods for the base oils was similar. The average number of carbons in paraffinic chains followed the same increasing trend from low viscosity to high viscosity base oils for the two methods.

Systematic chemical profiling of a multicomponent Chinese herbal formula Huo Luo Xiao Ling Dan by ultra high performance liquid chromatography coupled with electrospray ionization quadrupoletime-of-flight mass spectrometry.

PubMed

Wang, Fenrong; Ai, Yu; Wu, Yun; Ma, Wen; Bian, Qiaoxia; Lee, David Y-W; Dai, Ronghua

2015-03-01

Huo Luo Xiao Ling Dan, a Chinese herbal formula consisting of 11 different herbs, has been used in folk medicine for the treatment of arthritis and other chronic inflammatory diseases. However, the chemical compositions of Huo Luo Xiao Ling Dan are not completely characterized. In the present study, an ultra high performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight mass spectrometry method in positive and negative ion modes was employed to identify biochemical constitutes in Huo Luo Xiao Ling Dan. As a result, a total of 76 compounds including alkaloids, monoterpene glycosides, iridoids, phenolic acids, and tanshinones, coumarins, lactones, flavones, and their glycosides, triterpenes, and triterpene saponins were characterized by comparing the retention time and mass spectrometry data with reference standards within 5 ppm error or by reference to the reference literature. These results would provide the basis for a further in vivo study of Huo Luo Xiao Ling Dan and information for potential new drug candidates for treating arthritis and other chronic inflammatory diseases. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Metabolic profiling of Vitex agnus castus leaves, fruits and sprouts: analysis by LC/ESI/(QqQ)MS and (HR) LC/ESI/(Orbitrap)/MS n.

PubMed

Mari, Angela; Montoro, Paola; D'Urso, Gilda; Macchia, Mario; Pizza, Cosimo; Piacente, Sonia

2015-01-01

Food supplements based on Vitex agnus castus L. (Verbenaceae) fruits, also known as chasteberry, are routinely used by women against somatic and psychic premenstrual symptoms such as depression, sadness or irritability. With the aim of highlighting the differences in the chemical profiles of cultivated fruits and different parts of wild plants (fruits, leaves and sprouts) of V. agnus castus, a method concerning with the quali-quantitative study of the derived hydroalcoholic extracts was carried out by using high-performance liquid chromatography coupled to electrospray negative ionization Orbitrap multicollisional high resolution mass spectrometry (LC/ESI/(Orbitrap)MS(n)) and high-performance liquid chromatography coupled to electrospray negative ionization triple quadrupole tandem mass spectrometry (LC/ESI/(QqQ)MS) in multiple reaction monitoring (MRM) mode. Copyright © 2014 Elsevier B.V. All rights reserved.

Identification of five substituted phenethylamine derivatives 5-MAPDB, 5-AEDB, MDMA methylene homolog, 6-Br-MDMA, and 5-APB-NBOMe.

PubMed

Liu, Cuimei; Jia, Wei; Qian, Zhenhua; Li, Tao; Hua, Zhendong

2017-02-01

This paper reports analytical properties of five substituted phenethylamine derivatives seized from a clandestine laboratory. These five derivatives include 5-(2-methylaminopropyl)-2,3-dihydrobenzofuran (5-MAPDB, 1), 5-(2-aminoethyl)-2,3-dihydrobenzofuran (5-AEDB, 2), N,2-dimethyl-3-(3,4-methylenedioxyphenyl)propan-1-amine (MDMA methylene homolog, 3), 6-bromo-3,4-methylenedioxymethamphetamine (6-Br-MDMA, 4), and 1-(benzofuran-5-yl)-N-(2-methoxybenzyl)propan-2-amine (5-APB-NBOMe, 5). These compounds were identified by liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-QTOF-MS), gas chromatography-mass spectrometry (GC-MS), and nuclear magnetic resonance spectroscopy (NMR). No analytical properties about compounds 1-4 have appeared until now, making this the first report on these compounds. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Liquid chromatography with high resolution mass spectrometry for identification of organic contaminants in fish fillet: screening and quantification assessment using two scan modes for data acquisition.

PubMed

Munaretto, Juliana S; May, Marília M; Saibt, Nathália; Zanella, Renato

2016-07-22

This study proposed a strategy to identify and quantify 182 organic contaminants from different chemical classes, as for instance pesticides, veterinary drug and personal care products, in fish fillet using liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (LC-QToF/MS). For this purpose, two different scan methods (full scan and all ions MS/MS) were evaluated to assess the best option for screening analysis in spiked fish fillet samples. In general, full scan acquisition was found to be more reliable (84%) in the automatic identification and quantification when compared to all ions MS/MS with 72% of the compounds detected. Additionally, a qualitative automatic search showed a mass accuracy error below 5ppm for 77% of the compounds in full scan mode compared to only 52% in all ions MS/MS scan. However, all ions MS/MS provides fragmentation information of the target compounds. Undoubtedly, structural information of a wide number of compounds can be obtained using high resolution mass spectrometry (HRMS), but it is necessary thoroughly assess it, in order to choose the best scan mode. Copyright © 2016 Elsevier B.V. All rights reserved.

Nitrogen-Containing Low Volatile Compounds from Pinonaldehyde-Dimethylamine Reaction in the Atmosphere: A Laboratory and Field Study.

PubMed

Duporté, Geoffroy; Parshintsev, Jevgeni; Barreira, Luís M F; Hartonen, Kari; Kulmala, Markku; Riekkola, Marja-Liisa

2016-05-03

Pinonaldehyde, which is among the most abundant oxidation products of α-pinene, and dimethylamine were selected to study the formation of N-containing low volatile compounds from aldehyde-amine reactions in the atmosphere. Gas phase reactions took place in a Tedlar bag, which was connected to a mass spectrometer ionization source via a short deactivated fused silica column. In addition to on-line analysis, abundance of gaseous precursors and reaction products were monitored off-line. Condensable products were extracted from the bag's walls with a suitable solvent and analyzed by gas chromatography coupled to chemical ionization high-resolution quadrupole time-of-flight mass spectrometry and by ultra-high-performance liquid chromatography coupled to electrospray ionization Orbitrap mass spectrometry. The reactions carried out resulted in several mid-low vapor pressure nitrogen-containing compounds that are potentially important for the formation of secondary organic aerosols in the atmosphere. Further, the presence of brown carbon, confirmed by liquid chromatography-UV-vis-mass spectrometry, was observed. Some of the compounds identified in the laboratory study were also observed in aerosol samples collected at SMEAR II station (Hyytiälä, Finland) in August 2015 suggesting the importance of aldehyde-amine reactions for the aerosol formation and growth.

Comparison of different mass spectrometric approaches coupled to gas chromatography for the analysis of organochlorine pesticides in serum samples.

PubMed

Fang, Jing; Wu, Qian; Zhao, Yun; Zhao, Hongzhi; Xu, Shunqing; Cai, Zongwei

2017-01-01

Gas chromatography-triple quadrupole mass spectrometry (GC-QqQMS) was applied for the determination of eight organochlorine pesticides (OCPs) in human serum. OCPs were extracted from the serum sample by solid phase extraction (SPE) and analyzed by gas chromatography mass spectrometry (GC-MS) or gas chromatography tandem mass spectrometry (GC-MS/MS). Electron ionization (EI) and negative chemical ionization (NCI) under two data acquisition modes, namely selected ion monitoring (SIM) and multiple reaction monitoring (MRM), were compared. The use of MRM generally provided higher selectivity and sensitivity because less interference from the sample matrix existed. The EI mode is more suitable for less electronegative compounds such as dichlorodiphenyldichloroethanes (DDDs) with detection limits ranging from 0.0060 to 0.060ng/mL. In the NCI mode, MRM analysis provided good and lower detection limits (0.0011-0.0030ng/mL) for pesticides containing more chlorines. The methods were validated by analyzing the pesticides in spiked serum at different levels with recoveries ranged from 83% to 116% and relative standard deviations of less than 10%. The developed method was applied for the determination of the OCPs in real human serum samples. Copyright © 2016 Elsevier B.V. All rights reserved.

Differentiation of three pairs of aconite alkaloid isomers from Aconitum nagarum var. lasiandrum by electrospray ionization tandem mass spectrometry.

PubMed

Li, Rui; Wu, Zhijun; Zhang, Fan; Ding, Lisheng

2006-01-01

Three pairs of isomers of aconite alkaloids from Aconitum nagarum var. lasiandrum have been investigated by electrospray ionization mass spectrometry (ESI-MS) and tandem mass spectrometry (MS/MS) employing ion-trap and quadrupole time-of-flight mass spectrometers in positive mode. Based on the differences of their fragmentation pathways and special fragment ions, three pairs of isomers of aconite alkaloids were differentiated. In addition, fragmentation laws of some veatchines and the discrepancy of fragmentation mechanisms between veatchine-type and aconitine-type alkaloid were also concluded. In the case of veatchines, a radical would be formed by homolysis of C18--C4 or C18--H bonds, followed by elimination of a series of C(2)H(2) and C(2)H(4). Moreover, the retro-Diels-Alder (RDA) reaction occurred in the E-ring and double-electron transfer triggered by the positive charge on C1 led to the formation of diagnostic ions at m/z 216. With regard to aconitine-type alkaloids, the N-substituent is not eliminated easily. Although there is no carbonyl group on some aconitine-type alkaloids, with hydroxyl and methoxyl on C15 and C16 respectively, CO was readily eliminated through tautomerization.

CREATININE DETERMINATION IN URINE BY LIQUID CHROMATOGRAPHY-ELECTROSPRAY IONIZATION-TANDEM MASS SPECTROMETRY METHOD.

PubMed

Dereziński, Paweł; Klupczyńska, Agnieszka; Sawicki, Wojciech; Kokot, Zenon J

2016-01-01

Creatinine determination in urine is used to estimate the completeness of the 24-h urine collection, compensation for variable diuresis and as a preliminary step in protein profiling in urine. Despite the fact that a wide range of methods of measuring creatinine level in biofluids has been developed, many of them are adversely affected by interfering substances. A new liquid chromatography-tandem mass spectrometry method for creatinine determination in urine has been developed. Chromatographic separation was performed by applying C18 column and a gradient elution. Analyses were carried out on a triple quadrupole mass spectrometer equipped with an electrospray ion source. The developed method was fully validated according to the international guidelines. The quantification range of the method was 5-1500 ng/mL, which corresponds to 1-300 mg/dL in urine. Limit of detection and quantitation were 2 and 5 ng/mL, respectively. Additionally, the comparison of creatinine determination by newly developed method to the colorimetric method was performed. The method enables the determination of creatinine in urine samples with a minimal sample preparation, excellent sensitivity and prominent selectivity. Since mass spectrometry allows to measure a number of compounds simultaneously, a future perspective would be to incorporate the determination of other clinically important compounds excreted in urine.

A new ultrahigh performance liquid chromatography with diode array detection coupled to electrospray ionization and quadrupole time-of-flight mass spectrometry analytical strategy for fast analysis and improved characterization of phenolic compounds in apple products.

PubMed

Ramirez-Ambrosi, M; Abad-Garcia, B; Viloria-Bernal, M; Garmon-Lobato, S; Berrueta, L A; Gallo, B

2013-11-05

A new, rapid, selective and sensitive ultrahigh performance liquid chromatography with diode array detection coupled to electrospray ionization and quadrupole time-of-flight mass spectrometry (UHPLC-DAD-ESI-Q-ToF-MS) strategy using automatic and simultaneous acquisition of exact mass at high and low collision energy, MS(E), has been developed to obtain polyphenolic profile of apples, apple pomace and apple juice from Asturian cider apples in a single run injection of 22 min. MS(E) spectral data acquisition overcomes chromatographic co-elution problems, performing simultaneous collection of precursor ions as well as other ions produced as a result of their fragmentation, which allows resolving complex spectra from mixtures of precursor ions in an unsupervised way and eases their interpretation. Using this technique, 52 phenolic compounds of five different classes were readily characterized in these apple extracts in both positive and negative ionization modes. The spectral data for phenolic compounds obtained using this acquisition mode are comparable to those obtained by conventional LC-MS/MS as exemplified in this work. Among the 52 phenolic compounds identified in this work, 2 dihydrochalcones and 3 flavonols have been tentatively identified for the first time in apple products. Moreover, 2 flavanols, 4 dihydrochalcones, 9 hydroxycinnamic acids and 4 flavonols had not been previously reported in apple by ToF analysis to our knowledge. Copyright © 2013 Elsevier B.V. All rights reserved.

Fast analysis of doping agents in urine by ultra-high-pressure liquid chromatography-quadrupole time-of-flight mass spectrometry I. Screening analysis.

PubMed

Badoud, F; Grata, E; Perrenoud, L; Avois, L; Saugy, M; Rudaz, S; Veuthey, J-L

2009-05-15

The general strategy to perform anti-doping analyses of urine samples starts with the screening for a wide range of compounds. This step should be fast, generic and able to detect any sample that may contain a prohibited substance while avoiding false negatives and reducing false positive results. The experiments presented in this work were based on ultra-high-pressure liquid chromatography coupled to hybrid quadrupole time-of-flight mass spectrometry. Thanks to the high sensitivity of the method, urine samples could be diluted 2-fold prior to injection. One hundred and three forbidden substances from various classes (such as stimulants, diuretics, narcotics, anti-estrogens) were analysed on a C(18) reversed-phase column in two gradients of 9min (including two 3min equilibration periods) for positive and negative electrospray ionisation and detected in the MS full scan mode. The automatic identification of analytes was based on retention time and mass accuracy, with an automated tool for peak picking. The method was validated according to the International Standard for Laboratories described in the World Anti-Doping Code and was selective enough to comply with the World Anti-Doping Agency recommendations. In addition, the matrix effect on MS response was measured on all investigated analytes spiked in urine samples. The limits of detection ranged from 1 to 500ng/mL, allowing the identification of all tested compounds in urine. When a sample was reported positive during the screening, a fast additional pre-confirmatory step was performed to reduce the number of confirmatory analyses.

Unbiased metabolite profiling by liquid chromatography-quadrupole time-of-flight mass spectrometry and multivariate data analysis for herbal authentication: classification of seven Lonicera species flower buds.

PubMed

Gao, Wen; Yang, Hua; Qi, Lian-Wen; Liu, E-Hu; Ren, Mei-Ting; Yan, Yu-Ting; Chen, Jun; Li, Ping

2012-07-06

Plant-based medicines become increasingly popular over the world. Authentication of herbal raw materials is important to ensure their safety and efficacy. Some herbs belonging to closely related species but differing in medicinal properties are difficult to be identified because of similar morphological and microscopic characteristics. Chromatographic fingerprinting is an alternative method to distinguish them. Existing approaches do not allow a comprehensive analysis for herbal authentication. We have now developed a strategy consisting of (1) full metabolic profiling of herbal medicines by rapid resolution liquid chromatography (RRLC) combined with quadrupole time-of-flight mass spectrometry (QTOF MS), (2) global analysis of non-targeted compounds by molecular feature extraction algorithm, (3) multivariate statistical analysis for classification and prediction, and (4) marker compounds characterization. This approach has provided a fast and unbiased comparative multivariate analysis of the metabolite composition of 33-batch samples covering seven Lonicera species. Individual metabolic profiles are performed at the level of molecular fragments without prior structural assignment. In the entire set, the obtained classifier for seven Lonicera species flower buds showed good prediction performance and a total of 82 statistically different components were rapidly obtained by the strategy. The elemental compositions of discriminative metabolites were characterized by the accurate mass measurement of the pseudomolecular ions and their chemical types were assigned by the MS/MS spectra. The high-resolution, comprehensive and unbiased strategy for metabolite data analysis presented here is powerful and opens the new direction of authentication in herbal analysis. Copyright © 2012 Elsevier B.V. All rights reserved.

Liquid chromatography coupled to different atmospheric pressure ionization sources-quadrupole-time-of-flight mass spectrometry and post-column addition of metal salt solutions as a powerful tool for the metabolic profiling of Fusarium oxysporum.

PubMed

Cirigliano, Adriana M; Rodriguez, M Alejandra; Gagliano, M Laura; Bertinetti, Brenda V; Godeas, Alicia M; Cabrera, Gabriela M

2016-03-25

Fusarium oxysporum L11 is a non-pathogenic soil-borne fungal strain that yielded an extract that showed antifungal activity against phytopathogens. In this study, reversed-phase high-performance liquid chromatography (RP-HPLC) coupled to different atmospheric pressure ionization sources-quadrupole-time-of-flight mass spectrometry (API-QTOF-MS) was applied for the comprehensive profiling of the metabolites from the extract. The employed sources were electrospray (ESI), atmospheric pressure chemical ionization (APCI) and atmospheric pressure photoionization (APPI). Post-column addition of metal solutions of Ca, Cu and Zn(II) was also tested using ESI. A total of 137 compounds were identified or tentatively identified by matching their accurate mass signals, suggested molecular formulae and MS/MS analysis with previously reported data. Some compounds were isolated and identified by NMR. The extract was rich in cyclic peptides like cyclosporins, diketopiperazines and sansalvamides, most of which were new, and are reported here for the first time. The use of post-column addition of metals resulted in a useful strategy for the discrimination of compound classes since specific adducts were observed for the different compound families. This technique also allowed the screening for compounds with metal binding properties. Thus, the applied methodology is a useful choice for the metabolic profiling of extracts and also for the selection of metabolites with potential biological activities related to interactions with metal ions. Copyright © 2015 Elsevier B.V. All rights reserved.

[Determination of three exogenous plant hormone residues in bean sprout by high performance liquid chromatography-quadrupole-time of flight mass spectrometry].

PubMed

Xie, Hanbing; Zhou, Mingying; Zhao, Haifeng; Wang, Yigang; Jiang, Wanfeng; Zhao, Shan

2014-05-01

This study was aimed to the establishment of an analytical method for the determination of three exogenous plant hormone residues in bean sprout by high performance liquid chromatography-quadrupole-time of flight mass spectrometry (HPLC-Q-TOF-MS). The target compounds were gibberellins, 6-benzylaminopurine and parachlorophenoxyacetic acid. The QuEChERS (quick, easy, cheap, effective, rugged, and safe) method was used for sample preparation. The analytes were extracted with a solution containing 1% (v/v, if not specified) acetic, 50% ethanol, 49% acetonitrile, and cleaned-up by dispersive solid-phase extraction with diatomite dispersant, then degreased by hexane. The three target compounds were separated on an Eclipse Plus C18 column (100 mm x 3.0 mm, 1.8 microm) with mobile phases A (water containing 0.1% formic acid) and B (methanol) by gradient elution within 15 min, and detected under negative electrospray ionization (ESI) mode. The quantitative analysis was carried out by extracting the peak area with accurate mass. The confirmatory analysis of the target compounds was performed with the qualitative fragments. The results showed that the limits of quantification (LOQs, S/N = 10) for the three target compounds were from 5.0 microg/kg to 10 microg/kg. The respective mean recoveries were found to be in the range of 79.1%-96.1%, and the RSDs were 5.7%-10.4%. It was applicable to the analysis of the three exogenous plant hormones in bean sprout samples. This method is simple, fast and efficient.

Accurate determination of 3-alkyl-2-methoxypyrazines in wines by gas chromatography quadrupole time-of-flight tandem mass spectrometry following solid-phase extraction and dispersive liquid-liquid microextraction.

PubMed

Fontana, Ariel; Rodríguez, Isaac; Cela, Rafael

2017-09-15

A new reliable method for the determination 3-alkyl-2-methoxypyrazines (MPs) in wine samples based on the sequential combination of solid-phase extraction (SPE), dispersive liquid-liquid microextraction (DLLME) and gas chromatography (GC) quadrupole time-of-flight accurate tandem mass spectrometry (QTOF-MS/MS) is presented. Primary extraction of target analytes was carried out by using a reversed-phase Oasis HLB (200mg) SPE cartridge combined with acetonitrile as elution solvent. Afterwards, the SPE extract was submitted to DLLME concentration using 0.06mL carbon tetrachloride (CCl 4 ) as extractant. Under final working conditions, sample concentration factors above 379 times and limits of quantification (LOQs) between 0.3 and 2.1ngL -1 were achieved. Moreover, the overall extraction efficiency of the method was unaffected by the particular characteristics of each wine; thus, accurate results (relative recoveries from 84 to 108% for samples spiked at concentrations from 5 to 25ngL -1 ) were obtained using matrix-matched standards, without using standard additions over every sample. Highly selective chromatographic records were achieved considering a mass window of 5mDa, centered in the quantification product ion corresponding to each compound. Twelve commercial wines, elaborated with grapes from different varieties and geographical origins, were processed with the optimized method. The 2-isobutyl-3-methoxypyrazine (IBMP) was determined at levels above the LOQs of the method in half of the samples. Copyright © 2017 Elsevier B.V. All rights reserved.

Simultaneous identification and quantification of tetrodotoxin in fresh pufferfish and pufferfish-based products using immunoaffinity columns and liquid chromatography/quadrupole-linear ion trap mass spectrometry

NASA Astrophysics Data System (ADS)

Guo, Mengmeng; Wu, Haiyan; Jiang, Tao; Tan, Zhijun; Zhao, Chunxia; Zheng, Guanchao; Li, Zhaoxin; Zhai, Yuxiu

2017-07-01

In this study, we established a comprehensive method for simultaneous identification and quantification of tetrodotoxin (TTX) in fresh pufferfish tissues and pufferfish-based products using liquid chromatography/quadrupole-linear ion trap mass spectrometry (LC-QqLIT-MS). TTX was extracted by 1% acetic acid-methanol, and most of the lipids were then removed by freezing lipid precipitation, followed by purification and concentration using immunoaffinity columns (IACs). Matrix effects were substantially reduced due to the high specificity of the IACs, and thus, background interference was avoided. Quantitation analysis was therefore performed using an external calibration curve with standards prepared in mobile phase. The method was evaluated by fortifying samples at 1, 10, and 100 ng/g, respectively, and the recoveries ranged from 75.8%-107%, with a relative standard deviation of less than 15%. The TTX calibration curves were linear over the range of 1-1 000 μg/L, with a detection limit of 0.3 ng/g and a quantification limit of 1 ng/g. Using this method, samples can be further analyzed using an information-dependent acquisition (IDA) experiment, in the positive mode, from a single liquid chromatography-tandem mass spectrometry injection, which can provide an extra level of confirmation by matching the full product ion spectra acquired for a standard sample with those from an enhanced product ion (EPI) library. The scheduled multiple reaction monitoring method enabled TTX to be screened for, and TTX was positively identified using the IDA and EPI spectra. This method was successfully applied to analyze a total of 206 samples of fresh pufferfish tissues and pufferfish-based products. The results from this study show that the proposed method can be used to quantify and identify TTX in a single run with excellent sensitivity and reproducibility, and is suitable for the analysis of complex matrix pufferfish samples.

Amino acid analysis in physiological samples by GC-MS with propyl chloroformate derivatization and iTRAQ-LC-MS/MS.

PubMed

Dettmer, Katja; Stevens, Axel P; Fagerer, Stephan R; Kaspar, Hannelore; Oefner, Peter J

2012-01-01

Two mass spectrometry-based methods for the quantitative analysis of free amino acids are described. The first method uses propyl chloroformate/propanol derivatization and gas chromatography-quadrupole mass spectrometry (GC-qMS) analysis in single-ion monitoring mode. Derivatization is carried out directly in aqueous samples, thereby allowing automation of the entire procedure, including addition of reagents, extraction, and injection into the GC-MS. The method delivers the quantification of 26 amino acids. The isobaric tagging for relative and absolute quantification (iTRAQ) method employs the labeling of amino acids with isobaric iTRAQ tags. The tags contain two different cleavable reporter ions, one for the sample and one for the standard, which are detected by fragmentation in a tandem mass spectrometer. Reversed-phase liquid chromatography of the labeled amino acids is performed prior to mass spectrometric analysis to separate isobaric amino acids. The commercial iTRAQ kit allows for the analysis of 42 physiological amino acids with a respective isotope-labeled standard for each of these 42 amino acids.

A Researcher's Guide to Mass Spectrometry-Based Proteomics

PubMed Central

Savaryn, John P.; Toby, Timothy K.; Kelleher, Neil L.

2016-01-01

Mass spectrometry (MS) is widely recognized as a powerful analytical tool for molecular research. MS is used by researchers around the globe to identify, quantify, and characterize biomolecules like proteins from any number of biological conditions or sample types. As instrumentation has advanced, and with the coupling of liquid chromatography (LC) for high-throughput LC-MS/MS, a proteomics experiment measuring hundreds to thousands of proteins/protein groups is now commonplace. While expert practitioners who best understand the operation of LC-MS systems tend to have strong backgrounds in physics and engineering, consumers of proteomics data and technology are not exposed to the physio-chemical principles underlying the information they seek. Since articles and reviews tend not to focus on bridging this divide, our goal here is to span this gap and translate MS ion physics into language intuitive to the general reader active in basic or applied biomedical research. Here, we visually describe what happens to ions as they enter and move around inside a mass spectrometer. We describe basic MS principles, including electric current, ion optics, ion traps, quadrupole mass filters, and Orbitrap FT-analyzers. PMID:27553853

Improved sample preparation of glyphosate and methylphosphonic acid by EPA method 6800A and time-of-flight mass spectrometry using novel solid-phase extraction.

PubMed

Wagner, Rebecca; Wetzel, Stephanie J; Kern, John; Kingston, H M Skip

2012-02-01

The employment of chemical weapons by rogue states and/or terrorist organizations is an ongoing concern in the United States. The quantitative analysis of nerve agents must be rapid and reliable for use in the private and public sectors. Current methods describe a tedious and time-consuming derivatization for gas chromatography-mass spectrometry and liquid chromatography in tandem with mass spectrometry. Two solid-phase extraction (SPE) techniques for the analysis of glyphosate and methylphosphonic acid are described with the utilization of isotopically enriched analytes for quantitation via atmospheric pressure chemical ionization-quadrupole time-of-flight mass spectrometry (APCI-Q-TOF-MS) that does not require derivatization. Solid-phase extraction-isotope dilution mass spectrometry (SPE-IDMS) involves pre-equilibration of a naturally occurring sample with an isotopically enriched standard. The second extraction method, i-Spike, involves loading an isotopically enriched standard onto the SPE column before the naturally occurring sample. The sample and the spike are then co-eluted from the column enabling precise and accurate quantitation via IDMS. The SPE methods in conjunction with IDMS eliminate concerns of incomplete elution, matrix and sorbent effects, and MS drift. For accurate quantitation with IDMS, the isotopic contribution of all atoms in the target molecule must be statistically taken into account. This paper describes two newly developed sample preparation techniques for the analysis of nerve agent surrogates in drinking water as well as statistical probability analysis for proper molecular IDMS. The methods described in this paper demonstrate accurate molecular IDMS using APCI-Q-TOF-MS with limits of quantitation as low as 0.400 mg/kg for glyphosate and 0.031 mg/kg for methylphosphonic acid. Copyright © 2012 John Wiley & Sons, Ltd.

Negative chemical ionization gas chromatography coupled to hybrid quadrupole time-of-flight mass spectrometry and automated accurate mass data processing for determination of pesticides in fruit and vegetables.

PubMed

Besil, Natalia; Uclés, Samanta; Mezcúa, Milagros; Heinzen, Horacio; Fernández-Alba, Amadeo R

2015-08-01

Gas chromatography coupled to high resolution hybrid quadrupole time-of-flight mass spectrometry (GC-QTOF MS), operating in negative chemical ionization (NCI) mode and combining full scan with MSMS experiments using accurate mass analysis, has been explored for the automated determination of pesticide residues in fruit and vegetables. Seventy compounds were included in this approach where 50 % of them are not approved by the EU legislation. A global 76 % of the analytes could be identified at 1 μg kg(-1). Recovery studies were developed at three concentration levels (1, 5, and 10 μg kg(-1)). Seventy-seven percent of the detected pesticides at the lowest level yielded recoveries within the 70 %-120 % range, whereas 94 % could be quantified at 5 μg kg(-1), and the 100 % were determined at 10 μg kg(-1). Good repeatability, expressed as relative standard deviation (RSD <20 %), was obtained for all compounds. The main drawback of the method was the limited dynamic range that was observed for some analytes that can be overcome either diluting the sample or lowering the injection volume. A home-made database was developed and applied to an automatic accurate mass data processing. Measured mass accuracies of the generated ions were mainly less than 5 ppm for at least one diagnostic ion. When only one ion was obtained in the single-stage NCI-MS, a representative product ion from MSMS experiments was used as identification criterion. A total of 30 real samples were analyzed and 67 % of the samples were positive for 12 different pesticides in the range 1.0-1321.3 μg kg(-1).

Identification of polypropylene glycols and polyethylene glycol carboxylates in flowback and produced water from hydraulic fracturing.

PubMed

Thurman, E Michael; Ferrer, Imma; Rosenblum, James; Linden, Karl; Ryan, Joseph N

2017-02-05

The purpose of the study was to separate and identify the unknown surfactants present in flowback and produced water from oil and gas wells in the Denver-Julesburg Basin (Niobrara Formation) in Weld County, Colorado, USA. Weld County has been drilled extensively during the last five years for oil and gas between 7000-8000 feet below land-surface. Polypropylene glycols (PPGs) and polyethylene glycols carboxylates (PEG-Cs) were found for the first time in these flowback and produced water samples. These ethoxylated surfactants may be used as friction reducers, clay stabilizers, and surfactants. Ultrahigh-performance liquid chromatography/quadrupole-time-of-flight mass spectrometry (UHPLC/QTOF-MS) was used to separate and identify the different classes of PPGs, PEG-Cs, and their isomers. The Kendrick mass scale was applied along with mass spectrometry/mass spectrometry (MS-MS) with accurate mass for rapid and unequivocal identification. The PPGs and their isomers occur at the ppm concentration range and may be useful as "fingerprints" of hydraulic-fracturing. Comparing these detections to the compounds used in the fracturing process from FracFocus 3.0 (https://fracfocus.org), it appears that both PPGs and polyethylene glycols (PEGs) are commonly named as additives, but the PEG-Cs have not been reported. The PEG-Cs may be trace impurities or degradation products of PEGs. Copyright © 2016 Elsevier B.V. All rights reserved.

Portable Dew Point Mass Spectrometry System for Real-Time Gas and Moisture Analysis

NASA Technical Reports Server (NTRS)

Arkin, C.; Gillespie, Stacey; Ratzel, Christopher

2010-01-01

A portable instrument incorporates both mass spectrometry and dew point measurement to provide real-time, quantitative gas measurements of helium, nitrogen, oxygen, argon, and carbon dioxide, along with real-time, quantitative moisture analysis. The Portable Dew Point Mass Spectrometry (PDP-MS) system comprises a single quadrupole mass spectrometer and a high vacuum system consisting of a turbopump and a diaphragm-backing pump. A capacitive membrane dew point sensor was placed upstream of the MS, but still within the pressure-flow control pneumatic region. Pressure-flow control was achieved with an upstream precision metering valve, a capacitance diaphragm gauge, and a downstream mass flow controller. User configurable LabVIEW software was developed to provide real-time concentration data for the MS, dew point monitor, and sample delivery system pressure control, pressure and flow monitoring, and recording. The system has been designed to include in situ, NIST-traceable calibration. Certain sample tubing retains sufficient water that even if the sample is dry, the sample tube will desorb water to an amount resulting in moisture concentration errors up to 500 ppm for as long as 10 minutes. It was determined that Bev-A-Line IV was the best sample line to use. As a result of this issue, it is prudent to add a high-level humidity sensor to PDP-MS so such events can be prevented in the future.

A gas chromatography/high-resolution mass spectrometry (GC/HRMS) method for determination of polybrominated diphenyl ethers in fish.

PubMed

Alaee, M; Sergeant, D B; Ikonomou, M G; Luross, J M

2001-09-01

A method for the determination of polybrominated diphenyl ethers (PBDEs) in biota for routine analysis is described. The mass spectroscopic (MS) evaluation of 23 brominated diphenyl ethers, under electron ionization and electron capture negative ion conditions using magnetic sector and quadrupole mass spectrometers, showed that high-resolution mass spectrometry (HRMS) under electron ionization conditions was the most reliable technique, with high selectivity and adequate sensitivity. The instrument detection limit for this method ranged for individual congeners between 4.8 and 0.1 pg for 3-bromodiphenyl ether (BDE-2) and 2,3',4,4'-tetrabromodiphenyl ether (BDE-66), respectively, and method detection limit for each homologue group ranged between 5 pg/g for salmon certified reference material (CRM) and 93 pg/g for lake trout CRM. The effectiveness of this method was evaluated by analyzing the occurrence of PBDEs in commercially available CRMs comprising Lake Ontario lake trout, Pacific herring, and sockeye salmon. The average coefficients of variation for the replicate analyses of PDBEs in several tissue samples were: 25% for lake trout, 36% for Pacific herring, and 34% for sockeye salmon. The average deviations in the inter-laboratory study were: 14% for lake trout, 15% for Pacific herring, and 37% for sockeye salmon. Results indicated that the described method, based on gas chromatography/high-resolution mass spectrometry, is reliable for determining PBDE concentrations in biological tissues.

Corchorus Olitorius Linn: A Rich Source of Ω3-Fatty Acids.

PubMed

Mahmoud, A S; Thao, N; Mario, A

2016-06-01

Fatty acids composition of Corchorus olitorius Linn were identified as their methyl esters using accurate mass gas chromatography quadrupole time of flight mass spectrometry (GCQTOF) in chemical ionization (CI) and electron ionization (EI) modes. The leaves which are the edible part of the plant were found to be very rich in ω3-octadecatriene fatty acid reaching up to more than 49 % of the total fatty acids contents. This is the first report to unequivocally detect ω-3 fatty acid in Corchorus olitorius Linn with a much higher concentration than any other reported vegetable and further investigation into its health effects are clearly warranted.

Corchorus Olitorius Linn: A Rich Source of Ω3-Fatty Acids

PubMed Central

Mahmoud, AS; Thao, N; Mario, A

2016-01-01

Fatty acids composition of Corchorus olitorius Linn were identified as their methyl esters using accurate mass gas chromatography quadrupole time of flight mass spectrometry (GCQTOF) in chemical ionization (CI) and electron ionization (EI) modes. The leaves which are the edible part of the plant were found to be very rich in ω3-octadecatriene fatty acid reaching up to more than 49 % of the total fatty acids contents. This is the first report to unequivocally detect ω-3 fatty acid in Corchorus olitorius Linn with a much higher concentration than any other reported vegetable and further investigation into its health effects are clearly warranted. PMID:27722021

High resolution full scan liquid chromatography mass spectrometry comprehensive screening in sports antidoping urine analysis.

PubMed

Abushareeda, Wadha; Vonaparti, Ariadni; Saad, Khadija Al; Almansoori, Moneera; Meloug, Mbarka; Saleh, Amal; Aguilera, Rodrigo; Angelis, Yiannis; Horvatovich, Peter L; Lommen, Arjen; Alsayrafi, Mohammed; Georgakopoulos, Costas

2018-03-20

The aim of this paper is to present the development and validation of a high-resolution full scan (HR-FS) electrospray ionization (ESI) liquid chromatography coupled to quadrupole Orbitrap mass spectrometer (LC/Q/Orbitrap MS) platform for the screening of prohibited substances in human urine according to World Antidoping Agency (WADA) requirements. The method was also validated for quantitative analysis of six endogenous steroids (epitestosterone, testosterone, 5α-dihydrotestosterone, dehydroepiandrosterone, androsterone and etiocholanolone) in their intact sulfates form. The sample preparation comprised a combination of a hydrolyzed urine liquid-liquid extraction and the dilute & shoot addition of original urine in the extracted aliquot. The HR-FS MS acquisition mode with Polarity Switching was applied in combination of the Quadrupole-Orbitrap mass filter. The HR-FS acquisition of analytical signal, for known and unknown small molecules, allows the inclusion of all analytes detectable with LC-MS for antidoping investigations to identify the use of known or novel prohibited substances and metabolites after electronic data files' reprocessing. The method has been validated to be fit-for-purpose for the antidoping analysis. Copyright © 2017 Elsevier B.V. All rights reserved.

Evaluation and performance of desorption electrospray ionization using a triple quadrupole mass spectrometer for quantitation of pharmaceuticals in plasma.

PubMed

Kennedy, Joseph H; Wiseman, Justin M

2010-02-01

The present work describes the methodology and investigates the performance of desorption electrospray ionization (DESI) combined with a triple quadrupole mass spectrometer for the quantitation of small drug molecules in human plasma. Amoxepine, atenolol, carbamazepine, clozapine, prazosin, propranolol and verapamil were selected as target analytes while terfenadine was selected as the internal standard common to each of the analytes. Protein precipitation of human plasma using acetonitrile was utilized for all samples. Limits of detection were determined for all analytes in plasma and shown to be in the range 0.2-40 ng/mL. Quantitative analysis of amoxepine, prazosin and verapamil was performed over the range 20-7400 ng/mL and shown to be linear in all cases with R(2) >0.99. In most cases, the precision (relative standard deviation) and accuracy (relative error) of each method were less than or equal to 20%, respectively. The performance of the combined techniques made it possible to analyze each sample in 15 s illustrating DESI tandem mass spectrometry (MS/MS) as powerful tool for the quantitation of analytes in deproteinized human plasma. Copyright 2010 John Wiley & Sons, Ltd.

Suspected-target pesticide screening using gas chromatography-quadrupole time-of-flight mass spectrometry with high resolution deconvolution and retention index/mass spectrum library.

PubMed

Zhang, Fang; Wang, Haoyang; Zhang, Li; Zhang, Jing; Fan, Ruojing; Yu, Chongtian; Wang, Wenwen; Guo, Yinlong

2014-10-01

A strategy for suspected-target screening of pesticide residues in complicated matrices was exploited using gas chromatography in combination with hybrid quadrupole time-of-flight mass spectrometry (GC-QTOF MS). The screening workflow followed three key steps of, initial detection, preliminary identification, and final confirmation. The initial detection of components in a matrix was done by a high resolution mass spectrum deconvolution; the preliminary identification of suspected pesticides was based on a special retention index/mass spectrum (RI/MS) library that contained both the first-stage mass spectra (MS(1) spectra) and retention indices; and the final confirmation was accomplished by accurate mass measurements of representative ions with their response ratios from the MS(1) spectra or representative product ions from the second-stage mass spectra (MS(2) spectra). To evaluate the applicability of the workflow in real samples, three matrices of apple, spinach, and scallion, each spiked with 165 test pesticides in a set of concentrations, were selected as the models. The results showed that the use of high-resolution TOF enabled effective extractions of spectra from noisy chromatograms, which was based on a narrow mass window (5 mDa) and suspected-target compounds identified by the similarity match of deconvoluted full mass spectra and filtering of linear RIs. On average, over 74% of pesticides at 50 ng/mL could be identified using deconvolution and the RI/MS library. Over 80% of pesticides at 5 ng/mL or lower concentrations could be confirmed in each matrix using at least two representative ions with their response ratios from the MS(1) spectra. In addition, the application of product ion spectra was capable of confirming suspected pesticides with specificity for some pesticides in complicated matrices. In conclusion, GC-QTOF MS combined with the RI/MS library seems to be one of the most efficient tools for the analysis of suspected-target pesticide residues in complicated matrices. Copyright © 2014 Elsevier B.V. All rights reserved.

Detailed phenolic composition of Vidal grape pomace by ultrahigh-performance liquid chromatography-tandem mass spectrometry.

PubMed

Luo, Lanxin; Cui, Yan; Zhang, Shuting; Li, Lingxi; Suo, Hao; Sun, Baoshan

2017-11-15

Vidal Blanc grape (Vitis vinifera cv.) is the predominant white grape variety used for the production of icewine in China's Liaoning province. In this paper, the development and validation of the method by ultrahigh-performance liquid chromatography-tandem mass spectrometry has been performed for determination of the detailed phenolic composition in the skin, seed and stem of Vidal grapes. The validation of the method was realized by calculating the linearity, repeatability, precision, stability and the limits of detection (LOD) and quantification (LOQ) of standard solutions. All the curves exhibited good linearity (r 2 >0.9997) and the LOD and LOQ were in the range of 0.002-0.025 and 0.006-0.086μg/ml, respectively. Good repeatability (RSD<4.3%) and stability (RSD<3.7%) were also found. Results confirmed that the developed method was more effective and sensitive for simultaneous determination of the major phenolic compounds in Vidal grape pomace. The optimized and validated method of ultrahigh-performance liquid chromatography tandem two complementary techniques, fourier transform ion cyclotron resonance mass spectrometry and triple-quadrupole mass spectrometry, allowed to identify and quantify up to 35 phenolic compounds in Vidal grape pomace, which has, as far as we know, been reported this grapevine variety for the first time. Seeds, skins and stems exhibited different qualitative and quantitative phenolic profiles. These results provided useful information for recovery of phenolic antioxidants from different parts of icewine pomace. Copyright © 2017. Published by Elsevier B.V.

A multi-residue method for 17 anticoccidial drugs and ractopamine in animal tissues by liquid chromatography-tandem mass spectrometry and time-of-flight mass spectrometry.

PubMed

Matus, Johanna L; Boison, Joe O

2016-05-01

A new and sensitive multi-residue liquid chromatography-tandem mass spectrometry (LC-MS/MS) and liquid chromatography-quadrupole time-of-flight-mass spectrometry (LC-QToF-MS) method was developed and validated for the determination and confirmation of residues of 17 anticoccidials, plus free ractopamine in poultry muscle and liver, and bovine muscle, liver, and kidney tissues. The 17 anticoccidials are lasalocid, halofuginone, narasin, monensin, semduramicin, ethopabate, robenidine, buquinolate, toltrazuril as its sulfone metabolite, maduramicin, salinomycin, diclazuril, amprolium, decoquinate, dinitolmide, clopidol, and the nicarbazin metabolite DNC (N,N1-bis(4-nitrophenyl)urea). The analytes were extracted and cleaned up within a 3-hour period by simply extracting the analytes into a solvent mixture with salts followed by centrifugation, dilution, and filtration. The validated method was used in a pilot study for the analysis of 173 samples that included quail liver, bovine kidney, liver, muscle, and horse muscle. The predominant residues found in this study were monensin, ractopamine, and lasalocid. The results of this pilot study showed that this new method is applicable to real samples, and is fit for use in a regulatory testing programme. © 2016 Her Majesty the Queen in Right of Canada. Drug Testing and Analysis. © 2016 John Wiley & Sons, Ltd. © 2016 Her Majesty the Queen in Right of Canada. Drug Testing and Analysis. © 2016 John Wiley & Sons, Ltd.

Miniature micromachined quadrupole mass spectrometer array and method of making the same

NASA Technical Reports Server (NTRS)

Chutjian, Ara (Inventor); Brennen, Reid A. (Inventor); Hecht, Michael (Inventor); Wiberg, Dean (Inventor); Orient, Otto (Inventor)

2001-01-01

The present invention provides a quadrupole mass spectrometer and an ion filter for use in the quadrupole mass spectrometer. The ion filter includes a thin patterned layer including a two-dimensional array of poles forming one or more quadrupoles. The patterned layer design permits the use of very short poles and with a very dense spacing of the poles, so that the ion filter may be made very small. Also provided is a method for making the ion filter and the quadrupole mass spectrometer. The method involves forming the patterned layer of the ion filter in such a way that as the poles of the patterned layer are formed, they have the relative positioning and alignment for use in a final quadrupole mass spectrometer device.

Miniature micromachined quadrupole mass spectrometer array and method of making the same

NASA Technical Reports Server (NTRS)

Fuerstenau, Stephen D. (Inventor); Yee, Karl Y. (Inventor); Chutjian, Ara (Inventor); Orient, Otto J. (Inventor); Rice, John T. (Inventor)

2002-01-01

The present invention provides a quadrupole mass spectrometer and an ion filter, or pole array, for use in the quadrupole mass spectrometer. The ion filter includes a thin patterned layer including a two-dimensional array of poles forming one or more quadrupoles. The patterned layer design permits the use of very short poles and with a very dense spacing of the poles, so that the ion filter may be made very small. Also provided is a method for making the ion filter and the quadrupole mass spectrometer. The method involves forming the patterned layer of the ion filter in such a way that as the poles of the patterned layer are formed, they have the relative positioning and alignment for use in a final quadrupole mass spectrometer device.

Miniature micromachined quadrupole mass spectrometer array and method of making the same

NASA Technical Reports Server (NTRS)

Chutjian, Ara (Inventor); Rice, John T. (Inventor); Fuerstenau, Stephen D. (Inventor); Orient, Otto J. (Inventor); Yee, Karl Y. (Inventor)

2000-01-01

The present invention provides a quadrupole mass spectrometer and an ion filter, or pole array, for use in the quadrupole mass spectrometer. The ion filter includes a thin patterned layer including a two-dimensional array of poles forming one or more quadrupoles. The patterned layer design permits the use of very short poles and with a very dense spacing of the poles, so that the ion filter may be made very small. Also provided is a method for making the ion filter and the quadrupole mass spectrometer. The method involves forming the patterned layer of the ion filter in such a way that as the poles of the patterned layer are formed, they have the relative positioning and alignment for use in a final quadrupole mass spectrometer device.

Miniature micromachined quadrupole mass spectrometer array and method of making the same

NASA Technical Reports Server (NTRS)

Yee, Karl Y. (Inventor); Fuerstenau, Stephen D. (Inventor); Orient, Otto J. (Inventor); Rice, John T. (Inventor); Chutjian, Ara (Inventor)

2001-01-01

The present invention provides a quadrupole mass spectrometer and an ion filter, or pole array, for use in the quadrupole mass spectrometer. The ion filter includes a thin patterned layer including a two-dimensional array of poles forming one or more quadrupoles. The patterned layer design permits the use of very short poles and with a very dense spacing of the poles, so that the ion filter may be made very small. Also provided is a method for making the ion filter and the quadrupole mass spectrometer. The method involves forming the patterned layer of the ion filter in such a way that as the poles of the patterned layer are formed, they have the relative positioning and alignment for use in a final quadrupole mass spectrometer device.

Miniature micromachined quadrupole mass spectrometer array and method of making the same

NASA Technical Reports Server (NTRS)

Hecht, Michael (Inventor); Wiberg, Dean (Inventor); Orient, Otto (Inventor); Brennen, Reid A. (Inventor); Chutjian, Ara (Inventor)

2001-01-01

The present invention provides a quadrupole mass spectrometer and an ion filter for use in the quadrupole mass spectrometer. The ion filter includes a thin patterned layer including a two-dimensional array of poles forming one or more quadrupoles. The patterned layer design permits the use of very short poles and with a very dense spacing of the poles, so that the ion filter may be made very small. Also provided is a method for making the ion filter and the quadrupole mass spectrometer. The method involves forming the patterned layer of the ion filter in such a way that as the poles of the patterned layer are formed, they have the relative positioning and aligrnent for use in a final quadrupole mass spectrometer device.

Miniature micromachined quadrupole mass spectrometer array and method of making the same

NASA Technical Reports Server (NTRS)

Orient, Otto (Inventor); Wiberg, Dean (Inventor); Brennen, Reid A. (Inventor); Hecht, Michael (Inventor); Chutjian, Ara (Inventor)

2000-01-01

The present invention provides a quadrupole mass spectrometer and an ion filter for use in the quadrupole mass spectrometer. The ion filter includes a thin patterned layer including a two-dimensional array of poles forming one or more quadrupoles. The patterned layer design permits the use of very short poles and with a very dense spacing of the poles, so that the ion filter may be made very small. Also provided is a method for making the ion filter and the quadrupole mass spectrometer. The method involves forming the patterned layer of the ion filter in such a way that as the poles of the patterned layer are formed, they have the relative positioning and alignment for use in a final quadrupole mass spectrometer device.

Characterization of metabolites of larotaxel in rat by liquid chromatography coupled with Q exactive high-resolution benchtop quadrupole orbitrap mass spectrometer.

PubMed

Liu, Zhenzhen; Hou, Pengyi; Liu, Lian; Qian, Feng

2018-03-01

1. Liquid-chromatography (LC) high-resolution (HR) mass spectrometry (MS) analysis can record HR full scans for drug metabolism studies. Larotaxel is a taxane analog that has the potential for the treatment of various types of cancer. 2. In this study, the metabolism of larotaxel was evaluated after an intravenous dose of 8 mg/kg via the caudal vein to healthy rats and its metabolites were characterized by high performance liquid chromatography coupled with a Q Exactive high-resolution benchtop quadrupole orbitrap mass spectrometer. Rat bio-samples were separated on a Capcell Pak C 18 column (2.1 i.d. × 100 mm; 2.7 μm) with mobile phase of acetonitrile and water. 3. As a result, a total of 34 metabolites were detected and identified by comparing the molecular masses, retention times and spectral patterns of the analytes with those of the parent drug. Three metabolites were confirmed by comparison with reference substances. 4. The prominent metabolites were mainly hydroxyl, dihydroxyl, trihydroxyl and 10-desacetyl analogs of larotaxel, some of which resulted from oxidation of the tert-butyl groups on the side chain and further oxidation and cyclization of the tert-butyl hydroxylated metabolites.

Screening of synthetic PDE-5 inhibitors and their analogues as adulterants: analytical techniques and challenges.

PubMed

Patel, Dhavalkumar Narendrabhai; Li, Lin; Kee, Chee-Leong; Ge, Xiaowei; Low, Min-Yong; Koh, Hwee-Ling

2014-01-01

The popularity of phosphodiesterase type 5 (PDE-5) enzyme inhibitors for the treatment of erectile dysfunction has led to the increase in prevalence of illicit sexual performance enhancement products. PDE-5 inhibitors, namely sildenafil, tadalafil and vardenafil, and their unapproved designer analogues are being increasingly used as adulterants in the herbal products and health supplements marketed for sexual performance enhancement. To date, more than 50 unapproved analogues of prescription PDE-5 inhibitors were found as adulterants in the literature. To avoid detection of such adulteration by standard screening protocols, the perpetrators of such illegal products are investing time and resources to synthesize exotic analogues and devise novel means for adulteration. A comprehensive review of conventional and advance analytical techniques to detect and characterize the adulterants is presented. The rapid identification and structural elucidation of unknown analogues as adulterants is greatly enhanced by the wide myriad of analytical techniques employed, including high performance liquid chromatography (HPLC), gas chromatography-mass spectrometry (GC-MS), liquid chromatography mass-spectrometry (LC-MS), nuclear magnetic resonance (NMR) spectroscopy, vibrational spectroscopy, liquid chromatography-Fourier transform ion cyclotron resonance-mass spectrometry (LC-FT-ICR-MS), liquid chromatograph-hybrid triple quadrupole linear ion trap mass spectrometer with information dependent acquisition, ultra high performance liquid chromatography-time of flight-mass spectrometry (UHPLC-TOF-MS), ion mobility spectroscopy (IMS) and immunoassay methods. The many challenges in detecting and characterizing such adulterants, and the need for concerted effort to curb adulteration in order to safe guard public safety and interest are discussed. Copyright © 2013 Elsevier B.V. All rights reserved.

Electron impact action spectroscopy of mass/charge selected macromolecular ions: Inner-shell excitation of ubiquitin protein

DOE PAGES

Rankovic, Milos Lj.; Giuliani, Alexandre; Milosavljevic, Aleksandar R.

2016-02-11

In this study, we have performed inner-shell electron impact action spectroscopy of mass and charge selected macromolecular ions. For this purpose, we have coupled a focusing electron gun with a linear quadrupole ion trap mass spectrometer. This experiment represents a proof of principle that an energy-tunable electron beam can be used in combination with radio frequency traps as an activation method in tandem mass spectrometry (MS 2) and allows performing action spectroscopy. Electron impact MS 2 spectra of multiply protonated ubiquitin protein ion have been recorded at incident electron energies around the carbon 1s excitation. Both MS 2 and singlemore » ionization energy dependence spectra are compared with literature data obtained using the soft X-ray activation conditions.« less

Electron impact action spectroscopy of mass/charge selected macromolecular ions: Inner-shell excitation of ubiquitin protein

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rankovic, Milos Lj.; Giuliani, Alexandre; Milosavljevic, Aleksandar R.

In this study, we have performed inner-shell electron impact action spectroscopy of mass and charge selected macromolecular ions. For this purpose, we have coupled a focusing electron gun with a linear quadrupole ion trap mass spectrometer. This experiment represents a proof of principle that an energy-tunable electron beam can be used in combination with radio frequency traps as an activation method in tandem mass spectrometry (MS 2) and allows performing action spectroscopy. Electron impact MS 2 spectra of multiply protonated ubiquitin protein ion have been recorded at incident electron energies around the carbon 1s excitation. Both MS 2 and singlemore » ionization energy dependence spectra are compared with literature data obtained using the soft X-ray activation conditions.« less

High precision mass measurements for wine metabolomics

PubMed Central

Roullier-Gall, Chloé; Witting, Michael; Gougeon, Régis D.; Schmitt-Kopplin, Philippe

2014-01-01

An overview of the critical steps for the non-targeted Ultra-High Performance Liquid Chromatography coupled with Quadrupole Time-of-Flight Mass Spectrometry (UPLC-Q-ToF-MS) analysis of wine chemistry is given, ranging from the study design, data preprocessing and statistical analyses, to markers identification. UPLC-Q-ToF-MS data was enhanced by the alignment of exact mass data from FTICR-MS, and marker peaks were identified using UPLC-Q-ToF-MS2. In combination with multivariate statistical tools and the annotation of peaks with metabolites from relevant databases, this analytical process provides a fine description of the chemical complexity of wines, as exemplified in the case of red (Pinot noir) and white (Chardonnay) wines from various geographic origins in Burgundy. PMID:25431760

Determination of boldenone sulfoconjugate and related steroid sulfates in equine urine by high-performance liquid chromatography/tandem mass spectrometry.

PubMed

Weidolf, L O; Lee, E D; Henion, J D

1988-03-01

Sulfoconjugated anabolic steroids were separated by micro-bore high-performance liquid chromatography. The eluent was introduced into the atmospheric pressure ion source of the triple-quadrupole mass spectrometer via an ion spray liquid chromatograph/mass spectrometer interface operated in the negative ion mode. The limit of detection was 10 pg on-column by selected ion monitoring of the molecular ion and the response increased linearly over a concentration range of 2.4 orders of magnitude. Following work-up by a liquid-solid extraction procedure of equine urine samples, full-scan daughter ion spectra of boldenone sulfate could be obtained up to 17 days after a therapeutic dose of boldenone undecylenate to a horse.

High precision mass measurements for wine metabolomics

NASA Astrophysics Data System (ADS)

Roullier-Gall, Chloé; Witting, Michael; Gougeon, Régis; Schmitt-Kopplin, Philippe

2014-11-01

An overview of the critical steps for the non-targeted Ultra-High Performance Liquid Chromatography coupled with Quadrupole Time-of-Flight Mass Spectrometry (UPLC-Q-ToF-MS) analysis of wine chemistry is given, ranging from the study design, data preprocessing and statistical analyses, to markers identification. UPLC-Q-ToF-MS data was enhanced by the alignment of exact mass data from FTICR-MS, and marker peaks were identified using UPLC-Q-ToF-MS². In combination with multivariate statistical tools and the annotation of peaks with metabolites from relevant databases, this analytical process provides a fine description of the chemical complexity of wines, as exemplified in the case of red (Pinot noir) and white (Chardonnay) wines from various geographic origins in Burgundy.

Ion trap simulation program, ITSIM: A powerful heuristic and predictive tool in ion trap mass spectrometry

NASA Astrophysics Data System (ADS)

Bui, Huy Anh

The multi-particle simulation program, ITSIM version 4.0, takes advantage of the enhanced performance of the Windows 95 and NT operating systems in areas such as memory management, user friendliness, flexibility of graphics and speed, to investigate the motion of ions in the quadrupole ion trap. The objective of this program is to use computer simulations based on mathematical models to improve the performance of the ion trap mass spectrometer. The simulation program can provide assistance in understanding fundamental aspects of ion trap mass spectrometry, precede and help to direct the course of experiments, as well as having didactic value in elucidating and allowing visualization of ion behavior under different experimental conditions. The program uses the improved Euler method to calculate ion trajectories as numerical solutions to the Mathieu differential equation. This Windows version can simultaneously simulate the trajectories of ions with a virtually unlimited number of different mass-to-charge ratios and hence allows realistic mass spectra, ion kinetic energy distributions and other experimentally measurable properties to be simulated. The large number of simulated ions allows examination of (i) the offsetting effects of mutual ion repulsion and collisional cooling in an ion trap and (ii) the effects of higher order fields. Field inhomogeneities arising from exit holes, electrode misalignment, imperfect electrode surfaces or new trap geometries can be simulated with the program. The simulated data are used to obtain mass spectra from mass-selective instability scans as well as by Fourier transformation of image currents induced by coherently moving ion clouds. Complete instruments, from an ion source through the ion trap mass analyzer to a detector, can now be simulated. Applications of the simulation program are presented and discussed. Comparisons are made between the simulations and experimental data. Fourier transformed experiments and a novel six-electrode ion trap mass spectrometer illustrate cases in which simulations precede new experiments. Broadband non-destructive ion detection based on induced image current measurements are described in the case of a quadrupole ion trap having cylindrical geometry.

Differentially pumped dual linear quadrupole ion trap mass spectrometer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Owen, Benjamin C.; Kenttamaa, Hilkka I.

The present disclosure provides a new tandem mass spectrometer and methods of using the same for analyzing charged particles. The differentially pumped dual linear quadrupole ion trap mass spectrometer of the present disclose includes a combination of two linear quadrupole (LQIT) mass spectrometers with differentially pumped vacuum chambers.

Determination of perfluorinated alkyl acids in corn, popcorn and popcorn bags before and after cooking by focused ultrasound solid-liquid extraction, liquid chromatography and quadrupole-time of flight mass spectrometry.

PubMed

Moreta, Cristina; Tena, María Teresa

2014-08-15

An analytical method is proposed to determine ten perfluorinated alkyl acids (PFAAs) [nine perfluorocarboxylic acids (PFCAs) and perfluorooctane sulfonate (PFOS)] in corn, popcorn and microwave popcorn packaging by focused ultrasound solid-liquid extraction (FUSLE) and ultra high performance liquid chromatography (UHPLC) coupled to quadrupole-time of flight mass spectrometry (QTOF-MS/MS). Selected PFAAs were extracted efficiently in only one 10-s cycle by FUSLE, a simple, safe and inexpensive technique. The developed method was validated for microwave popcorn bags matrix as well as corn and popcorn matrices in terms of linearity, matrix effect error, detection and quantification limits, repeatability and recovery values. The method showed good accuracy with recovery values around 100% except for the lowest chain length PFAAs, satisfactory reproducibility with RSDs under 16%, and sensitivity with limits of detection in the order of hundreds picograms per gram of sample (between 0.2 and 0.7ng/g). This method was also applied to the analysis of six microwave popcorn bags and the popcorn inside before and after cooking. PFCAs contents between 3.50ng/g and 750ng/g were found in bags, being PFHxA (perfluorohexanoic acid) the most abundant of them. However, no PFAAs were detected either corn or popcorn, therefore no migration was assumed. Copyright © 2014 Elsevier B.V. All rights reserved.

Ultra high performance liquid chromatography coupled with triple quadrupole mass spectrometry and chemometric analysis of licorice based on the simultaneous determination of saponins and flavonoids.

PubMed

Jiang, Zhenzuo; Wang, Yuefei; Zheng, Yunfeng; Yang, Jing; Zhang, Lei

2016-08-01

Licorice is among the most popular herbal medicines and frequently used in traditional medicine, food products, and cosmetics. In China, only Glycyrrhiza uralensis Fisch., Glycyrrhiza inflata Bat. and Glycyrrhiza glabra L. are officially used and are usually processed with honey prior to use. To maintain the quality of commercially available herbal products, a simple, rapid, and reliable ultra high performance liquid chromatography with triple quadrupole mass spectrometry was developed to investigate the major active constituents of commercially available licorice products. Nineteen components were accurately determined, including eight triterpenoid saponins, one triterpene, and ten flavonoids. Subsequently, multivariate statistical analysis methods were employed to further explore and interpret the experimental data. The results indicated that liquiritin apioside may be considered as a candidate index for the quality control of licorice as well as 18β-glycyrrhizic acid and liquiritin. In addition, both 18β-glycyrrhizic acid and licorice-saponin G2 can be used for discrimination between crude and honey-processed licorice. Furthermore, using 18β-glycyrrhizic acid and liquiritin as markers, this work revealed that the quality of licorice products may have declined in recent years. This highlights the need for additional effort focused on good agricultural practice during the processing of licorice. In summary, this study provides a valuable reference for the quality assessment of licorice. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Early Metabolome Profiling and Prognostic Value in Paraquat-Poisoned Patients: Based on Ultraperformance Liquid Chromatography Coupled To Quadrupole Time-of-Flight Mass Spectrometry.

PubMed

Hu, Lufeng; Hong, Guangliang; Tang, Yahui; Wang, Xianqin; Wen, Congcong; Lin, Feiyan; Lu, Zhongqiu

2017-12-18

Paraquat (PQ) has caused countless deaths throughout the world. There remains no effective treatment for PQ poisoning. Here we study the blood metabolome of PQ-poisoned patients using ultraperformance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (UPLC/Q-TOF MS). Patients were divided into groups according to blood PQ concentration. Healthy subjects served as controls. Metabolic features were statistically analyzed using multivariate pattern-recognition techniques to identify the most important metabolites. Selected metabolites were further compared with a series of clinical indexes to assess the prognostic value. PQ-poisoned patients showed substantial differences compared with healthy subjects. Based on variable of importance in the project (VIP) values and statistical analysis, 17 metabolites were selected and identified. These metabolites well-classified low PQ-poisoned patients, high PQ-poisoned patients, and healthy subjects, which was better than that of a complete blood count (CBC). Among the 17 metabolites, 20:3/18:1-PC (PC), LPA (0:0/16:0) (LPA), 19-oxo-deoxycorticosterone (19-oxo-DOC), and eicosapentaenoic acid (EPA) had prognostic value. In particular, EPA was the most sensitive one. Besides, the levels of EPA was correlated with LPA and 19-oxo-DOC. If EPA was excessively consumed, then prognosis was poor. In conclusion, the serum metabolome is substantially perturbed by PQ poisoning. EPA is the most important biomarker in early PQ poisoning.

Hydrogen measurement during steam oxidation using coupled thermogravimetric analysis and quadrupole mass spectrometry

DOE PAGES

Parkison, Adam J.; Nelson, Andrew Thomas

2016-01-11

An analytical technique is presented with the goal of measuring reaction kinetics during steam oxidation reactions for three cases in which obtaining kinetics information often requires a prohibitive amount of time and cost. The technique presented relies on coupling thermogravimetric analysis (TGA) with a quantitative hydrogen measurement technique using quadrupole mass spectrometry (QMS). The first case considered is in differentiating between the kinetics of steam oxidation reactions and those for simultaneously reacting gaseous impurities such as nitrogen or oxygen. The second case allows one to independently measure the kinetics of oxide and hydride formation for systems in which both ofmore » these reactions are known to take place during steam oxidation. The third case deals with measuring the kinetics of formation for competing volatile and non-volatile oxides during certain steam oxidation reactions. In order to meet the requirements of the coupled technique, a methodology is presented which attempts to provide quantitative measurement of hydrogen generation using QMS in the presence of an interfering fragmentation species, namely water vapor. This is achieved such that all calibrations and corrections are performed during the TGA baseline and steam oxidation programs, making system operation virtually identical to standard TGA. Benchmarking results showed a relative error in hydrogen measurement of 5.7–8.4% following the application of a correction factor. Lastly, suggestions are made for possible improvements to the presented technique so that it may be better applied to the three cases presented.« less

Determination of pesticide residues in samples of green minor crops by gas chromatography and ultra performance liquid chromatography coupled to tandem quadrupole mass spectrometry.

PubMed

Walorczyk, Stanisław; Drożdżyński, Dariusz; Kierzek, Roman

2015-01-01

A method was developed for pesticide analysis in samples of high chlorophyll content belonging to the group of minor crops. A new type of sorbent, known as ChloroFiltr, was employed for dispersive-solid phase extraction cleanup (dispersive-SPE) to reduce the unwanted matrix background prior to concurrent analysis by gas chromatography and ultra-performance liquid chromatography coupled to tandem quadrupole mass spectrometry (GC-MS/MS and UPLC-MS/MS). Validation experiments were carried out on green, unripe plants of lupin, white mustard and sorghum. The overall recoveries at the three spiking levels of 0.01, 0.05 and 0.5 mg kg(-1) fell in the range between 68 and 120% (98% on average) and 72-104% (93% on average) with relative standard deviation (RSD) values between 2 and 19% (7% on average) and 3-16% (6% on average) by GC-MS/MS and UPLC-MS/MS technique, respectively. Because of strong enhancement or suppression matrix effects (absolute values >20%) which were exhibited by about 80% of the pesticide and matrix combinations, acceptably accurate quantification was achieved by using matrix-matched standards. Up to now, the proposed method has been successfully used to study the dissipation patterns of pesticides after application on lupin, white mustard, soya bean, sunflower and field bean in experimental plot trials conducted in Poland. Copyright © 2014 Elsevier B.V. All rights reserved.

Profiling and multivariate statistical analysis of Panax ginseng based on ultra-high-performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry.

PubMed

Wu, Wei; Sun, Le; Zhang, Zhe; Guo, Yingying; Liu, Shuying

2015-03-25

An ultra-high-performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry (UHPLC-Q-TOF-MS) method was developed for the detection and structural analysis of ginsenosides in white ginseng and related processed products (red ginseng). Original neutral, malonyl, and chemically transformed ginsenosides were identified in white and red ginseng samples. The aglycone types of ginsenosides were determined by MS/MS as PPD (m/z 459), PPT (m/z 475), C-24, -25 hydrated-PPD or PPT (m/z 477 or m/z 493), and Δ20(21)-or Δ20(22)-dehydrated-PPD or PPT (m/z 441 or m/z 457). Following the structural determination, the UHPLC-Q-TOF-MS-based chemical profiling coupled with multivariate statistical analysis method was applied for global analysis of white and processed ginseng samples. The chemical markers present between the processed products red ginseng and white ginseng could be assigned. Process-mediated chemical changes were recognized as the hydrolysis of ginsenosides with large molecular weight, chemical transformations of ginsenosides, changes in malonyl-ginsenosides, and generation of 20-(R)-ginsenoside enantiomers. The relative contents of compounds classified as PPD, PPT, malonyl, and transformed ginsenosides were calculated based on peak areas in ginseng before and after processing. This study provides possibility to monitor multiple components for the quality control and global evaluation of ginseng products during processing. Copyright © 2014 Elsevier B.V. All rights reserved.

[Determination of hydroxyproline in liver tissue by hydrophilic interaction chromatography-quadrupole/electrostatic field orbitrap high resolution mass spectrometry].

PubMed

Liu, Wei; Qi, Shenglan; Xu, Ying; Xiao, Zhun; Fu, Yadong; Chen, Jiamei; Yang, Tao; Liu, Ping

2017-12-08

A method for the determination of hydroxyproline (Hyp) in liver tissue of mice by hydrophilic interaction chromatography-quadrupole/electrostatic field orbitrap high resolution mass spectrometry (HILIC-HRMS) was developed. The liver tissue samples of normal mice and liver fibrosis mice induced by carbon tetrachloride were hydrolyzed by concentrated hydrochloric acid. After filtrated and diluted by solution, the diluent was separated on an Hypersil GOLD HILIC column (100 mm×2.1 mm, 3 μm). Water-acetonitrile (28:72, v/v)were used as the mobile phases with isocratic elution. Finally, the target analytes were detected in positive model by HRMS equipped with an electrospray ionization source. The linear range of hydroxyproline was from 0.78 to 100.00 μg/L with the correlation coefficient ( R 2 ) of 0.9983. The limit of quantification was 0.78 μg/L. By detecting the spiked samples, the recoveries were in the range of 97.4%-100.9% with the relative standard deviations (RSDs) between 1.4% and 2.0%. In addition, comparison of the measurement results by this method and the chloramine T method was proceeded. It was found that the linear correlation between the two methods was very good, and the Pearson correlation coefficient was 0.927. And this method had simpler operation procedure and higher accuracy than chloramine T method. This method can be used for the quick determination of hydroxyproline in liver tissue samples.

Hydrogen measurement during steam oxidation using coupled thermogravimetric analysis and quadrupole mass spectrometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Parkison, Adam J.; Nelson, Andrew Thomas

An analytical technique is presented with the goal of measuring reaction kinetics during steam oxidation reactions for three cases in which obtaining kinetics information often requires a prohibitive amount of time and cost. The technique presented relies on coupling thermogravimetric analysis (TGA) with a quantitative hydrogen measurement technique using quadrupole mass spectrometry (QMS). The first case considered is in differentiating between the kinetics of steam oxidation reactions and those for simultaneously reacting gaseous impurities such as nitrogen or oxygen. The second case allows one to independently measure the kinetics of oxide and hydride formation for systems in which both ofmore » these reactions are known to take place during steam oxidation. The third case deals with measuring the kinetics of formation for competing volatile and non-volatile oxides during certain steam oxidation reactions. In order to meet the requirements of the coupled technique, a methodology is presented which attempts to provide quantitative measurement of hydrogen generation using QMS in the presence of an interfering fragmentation species, namely water vapor. This is achieved such that all calibrations and corrections are performed during the TGA baseline and steam oxidation programs, making system operation virtually identical to standard TGA. Benchmarking results showed a relative error in hydrogen measurement of 5.7–8.4% following the application of a correction factor. Lastly, suggestions are made for possible improvements to the presented technique so that it may be better applied to the three cases presented.« less

Determination of short chain chlorinated paraffins in water by stir bar sorptive extraction-thermal desorption-gas chromatography-triple quadrupole tandem mass spectrometry.

PubMed

Tölgyessy, P; Nagyová, S; Sládkovičová, M

2017-04-21

A simple, robust, sensitive and environment friendly method for the determination of short chain chlorinated paraffins (SCCPs) in water using stir bar sorptive extraction (SBSE) coupled to thermal desorption-gas chromatography-triple quadrupole tandem mass spectrometry (TD-GC-QqQ-MS/MS) was developed. SBSE was performed using 100mL of water sample, 20mL of methanol as a modifier, and a commercial sorptive stir bar (with 10mm×0.5mm PDMS layer) during extraction period of 16h. After extraction, the sorptive stir bar was thermally desorbed and online analysed by GC-MS/MS. Method performance was evaluated for MilliQ and surface water spiked samples. For both types of matrices, a linear dynamic range of 0.5-3.0μgL -1 with correlation coefficients >0.999 and relative standard deviations (RSDs) of the relative response factors (RRFs) <12% was established. The limits of quantification (LOQs) of 0.06 and 0.08μgL -1 , and the precision (repeatability) of 6.4 and 7.7% (RSDs) were achieved for MilliQ and surface water, respectively. The method also showed good robustness, recovery and accuracy. The obtained performance characteristics indicate that the method is suitable for screening and monitoring and compliance checking with environmental quality standards (EQS, set by the EU) for SCCPs in surface waters. Copyright © 2017 Elsevier B.V. All rights reserved.

Short-term toxicity assessments of an antibiotic metabolite in Wistar rats and its metabonomics analysis by ultra-high performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry.

PubMed

Han, Hongxing; Xiao, Hailong; Lu, Zhenmei

2016-02-15

4-Epi-oxytetracycline (4-EOTC), one of main oxytetracycline (OTC) metabolites, can be commonly detected in food and environment. The toxicity and effects of OTC on animals have been well characterized; however, its metabolites have never been studied systemically. This study aims to investigate 15-day oral dose toxicity and urine metabonomics changes of 4-EOTC after repeated administration in Wistar rats at daily doses of 0.5, 5.0 and 50.0mg/kg bw (bodyweight). Hematology and clinical chemistry parameters, including white blood cell count, red blood cell count, total protein, globulin and albumin/globulin, were obviously altered in rats of 5.0 and 50.0mg/kg bw. Histopathology changes of kidney and liver tissues were also observed in high-dose groups. Urinary metabolites from all groups were analyzed using ultra-high performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS). Seventeen metabolites contributing to the clusters were identified as potential biomarkers from multivariate analysis, including aminoadipic acid, 6-phosphogluconate, sebacic acid, pipecolic acid, etc. The significant changes of these biomarkers demonstrated metabonomic variations in treated rats, especially lysine and purine metabolism. For the first time in this paper, we combined the results of toxicity and metabonomics induced by 4-EOTC for the serious reconsideration of the safety and potential risks of antibiotics and its degradation metabolites. Copyright © 2016 Elsevier Inc. All rights reserved.

Lipidomic analysis of plasma in patients with lacunar infarction using normal-phase/reversed-phase two-dimensional liquid chromatography-quadrupole time-of-flight mass spectrometry.

PubMed

Yang, Li; Lv, Pu; Ai, Wanpeng; Li, Linnan; Shen, Sensen; Nie, Honggang; Shan, Yabing; Bai, Yu; Huang, Yining; Liu, Huwei

2017-05-01

Stroke is a major cause of mortality and long-term disability worldwide. The study of biomarkers and pathogenesis is vital for early diagnosis and treatment of stroke. In the present study, a continuous-flow normal-phase/reversed-phase two-dimensional liquid chromatography-quadrupole time-of-flight mass spectrometry (NP/RP 2D LC-QToF/MS) method was employed to measure lipid species in human plasma, including healthy controls and lacunar infarction (LI) patients. As a result, 13 lipid species were demonstrated with significant difference between the two groups, and a "plasma biomarker model" including glucosylceramide (38:2), phosphatidylethanolamine (35:2), free fatty acid (16:1), and triacylglycerol (56:5) was finally established. This model was evaluated as an effective tool in that area under the receiver operating characteristic curve reached 1.000 in the discovery set and 0.947 in the validation set for diagnosing LI patients from healthy controls. Besides, the sensitivity and specificity of disease diagnosis in validation set were 93.3% and 96.6% at the best cutoff value, respectively. This study demonstrates the promising potential of NP/RP 2D LC-QToF/MS-based lipidomics approach in finding bio-markers for disease diagnosis and providing special insights into the metabolism of stroke induced by small vessel disease. Graphical abstract Flow-chart of the plasma biomarker model establishment through biomarker screening and validation.

Metabolic Profile of Skimmianine in Rats Determined by Ultra-Performance Liquid Chromatography Coupled with Quadrupole Time-of-Flight Tandem Mass Spectrometry.

PubMed

Huang, Aihua; Xu, Hui; Zhan, Ruoting; Chen, Weiwen; Liu, Jiawei; Chi, Yuguang; Chen, Daidi; Ji, Xiaoyu; Luo, Chaoquan

2017-03-23

Skimmianine is a furoquinoline alkaloid present mainly in the Rutaceae family. It has been reported to have analgesic, antispastic, sedative, anti-inflammatory, and other pharmacologic activities. Despite its critical pharmacological function, its metabolite profiling is still unclear. In this study, the in vivo metabolite profiling of skimmianine in rats was investigated using ultra-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry (UPLC/Q-TOF-MS). The metabolites were predicted using MetabolitePilot TM software. These predicted metabolites were further analyzed by MS² spectra, and compared with the detailed fragmentation pathway of the skimmianine standard and literature data. A total of 16 metabolites were identified for the first time in rat plasma, urine, and feces samples after oral administration of skimmianine. Skimmianine underwent extensive Phase I and Phase II metabolism in rats. The Phase I biotransformations of skimmianine consist of epoxidation of olefin on its furan ring (M1) followed by the hydrolysis of the epoxide ring (M4), hydroxylation (M2, M3), O -demethylation (M5-M7), didemethylation (M14-M16). The Phase II biotransformations include glucuronide conjugation (M8-M10) and sulfate conjugation (M11-M13). The epoxidation of 2,3-olefinic bond followed by the hydrolysis of the epoxide ring and O -demethylation were the major metabolic pathways of skimmianine. The results provide key information for understanding the biotransformation processes of skimmianine and the related furoquinoline alkaloids.

Identification of phase I and II metabolites of the new designer drug α-pyrrolidinohexiophenone (α-PHP) in human urine by liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QTOF-MS).

PubMed

Paul, Michael; Bleicher, Sergej; Guber, Susanne; Ippisch, Josef; Polettini, Aldo; Schultis, Wolfgang

2015-11-01

Pyrrolidinophenones represent one emerging class of newly encountered drugs of abuse, also known as 'new psychoactive substances', with stimulating psychoactive effects. In this work, we report on the detection of the new designer drug α-pyrrolidinohexiophenone (α-PHP) and its phase I and II metabolites in a human urine sample of a drug abuser. Determination and structural elucidation of these metabolites have been achieved by liquid chromatography electrospray ionisation quadrupole time-of-flight mass spectrometry (LC-ESI-QTOF-MS). By tentative identification, the exact and approximate structures of 19 phase I metabolites and nine phase II glucuronides were elucidated. Major metabolic pathways revealed the reduction of the ß-keto moieties to their corresponding alcohols, didesalkylation of the pyrrolidine ring, hydroxylation and oxidation of the aliphatic side chain leading to n-hydroxy, aldehyde and carboxylate metabolites, and oxidation of the pyrrolidine ring to its lactam followed by ring cleavage and additional hydroxylation, reduction and oxidation steps and combinations thereof. The most abundant phase II metabolites were glucuronidated ß-keto-reduced alcohols. Besides the great number of metabolites detected in this sample, α-PHP is still one of the most abundant ions together with its ß-keto-reduced alcoholic dihydro metabolite. Monitoring of these metabolites in clinical and forensic toxicology may unambiguously prove the abuse of the new designer drug α-PHP. Copyright © 2015 John Wiley & Sons, Ltd.

Metabolomics study on primary dysmenorrhea patients during the luteal regression stage based on ultra performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry

PubMed Central

Fang, Ling; Gu, Caiyun; Liu, Xinyu; Xie, Jiabin; Hou, Zhiguo; Tian, Meng; Yin, Jia; Li, Aizhu; Li, Yubo

2017-01-01

Primary dysmenorrhea (PD) is a common gynecological disorder which, while not life-threatening, severely affects the quality of life of women. Most patients with PD suffer ovarian hormone imbalances caused by uterine contraction, which results in dysmenorrhea. PD patients may also suffer from increases in estrogen levels caused by increased levels of prostaglandin synthesis and release during luteal regression and early menstruation. Although PD pathogenesis has been previously reported on, these studies only examined the menstrual period and neglected the importance of the luteal regression stage. Therefore, the present study used urine metabolomics to examine changes in endogenous substances and detect urine biomarkers for PD during luteal regression. Ultra performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry was used to create metabolomic profiles for 36 patients with PD and 27 healthy controls. Principal component analysis and partial least squares discriminate analysis were used to investigate the metabolic alterations associated with PD. Ten biomarkers for PD were identified, including ornithine, dihydrocortisol, histidine, citrulline, sphinganine, phytosphingosine, progesterone, 17-hydroxyprogesterone, androstenedione, and 15-keto-prostaglandin F2α. The specificity and sensitivity of these biomarkers was assessed based on the area under the curve of receiver operator characteristic curves, which can be used to distinguish patients with PD from healthy controls. These results provide novel targets for the treatment of PD. PMID:28098892

Concerns about Quadrupole ICP-MS Lead Isotopic Data and Interpretations in the Environment and Health Fields.

PubMed

Gulson, Brian; Kamenov, George D; Manton, William; Rabinowitz, Michael

2018-04-11

There has been a massive increase in recent years of the use of lead (Pb) isotopes in attempts to better understand sources and pathways of Pb in the environment and in man or experimental animals. Unfortunately, there have been many cases where the quality of the isotopic data, especially that obtained by quadrupole inductively coupled plasma mass spectrometry (Q-ICP-MS), are questionable, resulting in questionable identification of potential sources, which, in turn, impacts study interpretation and conclusions. We present several cases where the isotopic data have compromised interpretation because of the use of only the major isotopes 208 Pb/ 206 Pb and 207 Pb/ 206 Pb, or their graphing in other combinations. We also present some examples comparing high precision data from thermal ionization (TIMS) or multi-collector plasma mass spectrometry (MC-ICP-MS) to illustrate the deficiency in the Q-ICP-MS data. In addition, we present cases where Pb isotopic ratios measured on Q-ICP-MS are virtually impossible for terrestrial samples. We also evaluate the Pb isotopic data for rat studies, which had concluded that Pb isotopic fractionation occurs between different organs and suggest that this notion of biological fractionation of Pb as an explanation for isotopic differences is not valid. Overall, the brief review of these case studies shows that Q-ICP-MS as commonly practiced is not a suitable technique for precise and accurate Pb isotopic analysis in the environment and health fields.

Lithium adduct as precursor ion for sensitive and rapid quantification of 20 (S)-protopanaxadiol in rat plasma by liquid chromatography/quadrupole linear ion trap mass spectrometry and application to rat pharmacokinetic study.

PubMed

Bao, Yuanwu; Wang, Quanying; Tang, Pingming

2013-03-01

A novel, rapid and sensitive liquid chromatography/quadrupole linear ion trap mass spectrometry [LC-ESI-(QqLIT)MS/MS] method was developed and validated for the quantification of protopanaxadiol (PPD) in rat plasma. Oleanolic acid (OA) was used as internal standard (IS). A simple protein precipitation based on acetonitrile (ACN) was employed. Chromatographic separation was performed on a Sepax GP-C18 column (50 × 2.1 mm, 5 μM) with a mobile phase consisting of ACN-water and 1.5 μM formic acid and 25 mM lithium acetate (90 : 10, v/v) at a flow rate of 0.4 ml/min for 3.0 min. Multiple-reaction-monitoring mode was performed using lithium adduct ion as precursor ion of m/z 467.5/449.4 and 455.6/407.4 for the drug and IS, respectively. Calibration curve was recovered over a concentration range of 0.5-100 ng/ml with a correlation coefficient >0.99. The limit of detection was 0.2 ng/ml in rat plasma for PPD. The results of the intraday and interday precision and accuracy studies were well within the acceptable limits. The validated method was successfully applied to investigate the pharmacokinetic study of PPD after intravenous and gavage administration to rat. Copyright © 2013 John Wiley & Sons, Ltd.

Development of a systematic strategy for the global identification and classification of the chemical constituents and metabolites of Kai-Xin-San based on liquid chromatography with quadrupole time-of-flight mass spectrometry combined with multiple data-processing approaches.

PubMed

Wang, Xiaotong; Liu, Jing; Yang, Xiaomei; Zhang, Qian; Zhang, Yiwen; Li, Qing; Bi, Kaishun

2018-03-30

To rapidly identify and classify complicated components and metabolites for traditional Chinese medicines, a liquid chromatography with quadrupole time-of-flight mass spectrometry method combined with multiple data-processing approaches was established. In this process, Kai-Xin-San, a widely used classic traditional Chinese medicine preparation, was chosen as a model prescription. Initially, the fragmentation patterns, diagnostic product ions and neutral loss of each category of compounds were summarized by collision-induced dissociation analysis of representative standards. In vitro, the multiple product ions filtering technique was utilized to identify the chemical constituents for globally covering trace components. With this strategy, 108 constituents were identified, and compounds database was successfully established. In vivo, the prototype compounds were extracted based on the established database, and the neutral loss filtering technique combined with the drug metabolism reaction rules was employed to identify metabolites. Overall, 69 constituents including prototype and metabolites were characterized in rat plasma and nine constituents were firstly characterized in rat brain, which may be the potential active constituents resulting in curative effects by synergistic interaction. In conclusion, this study provides a generally applicable strategy to global metabolite identification for the complicated components in complex matrix and a chemical basis for further pharmacological research of Kai-Xin-San. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Simultaneous detection of flumethasone, dl-methylephedrine, and 2-hydroxy-4,6-dimethylpyrimidine in porcine muscle and pasteurized cow milk using liquid chromatography coupled with triple-quadrupole mass spectrometry.

PubMed

Zhang, Dan; Park, Jin-A; Kim, Seong-Kwan; Cho, Sang-Hyun; Jeong, Daun; Cho, Soo-Min; Yi, Hee; Shim, Jae-Han; Kim, Jin-Suk; Abd El-Aty, A M; Shin, Ho-Chul

2016-02-15

A simple analytical method based on liquid chromatography coupled with triple-quadrupole mass spectrometry was developed for detection of the veterinary drugs flumethasone, dl-methylephedrine, and 2-hydroxy-4,6-dimethylpyrimidine in porcine muscle and pasteurized cow milk. The target drugs were extracted from samples using 10mM ammonium formate in acetonitrile followed by clean-up with n-hexane and primary secondary amine sorbent (PSA). The analytes were separated on an XBridge™ hydrophilic interaction liquid chromatography (HILIC) column using 10mM ammonium formate in ultrapure water and acetonitrile. Good linearity was achieved over the tested concentrations in matrix-fortified calibrations with correlation coefficients (R(2))≥0.9686. Recovery at two spiking levels ranged between 73.62-112.70% with intra- and inter-day precisions of ≤20.33%. The limits of quantification ranged from 2-10ng/g in porcine muscle and pasteurized cow milk. A survey of market samples showed that none of them contained any of the target analytes. Liquid-liquid purification using n-hexane in combination with PSA efficiently removed the interferences during porcine and milk sample extraction. The developed method is sensitive and reliable for detection of the three target drugs in a single chromatographic run. Furthermore, it exhibits high selectivity and low quantification limits for animal-derived food products destined for human consumption. Copyright © 2016 Elsevier B.V. All rights reserved.

Simultaneous quantitative determination of 11 sesquiterpene lactones in Jerusalem artichoke (Helianthus tuberosus L.) leaves by ultra high performance liquid chromatography with quadrupole time-of-flight mass spectrometry.

PubMed

Yuan, Xiaoyan; Yang, Qianxu

2017-04-01

A method of ultra high performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry was developed for the simultaneous quantification of 11 sesquiterpene lactones in 11 Jerusalem artichoke leaf samples harvested in a number of areas at different periods. The optimal chromatographic conditions were achieved on a ZORBAX Eclipse Plus C 18 column (3.0 × 150 mm, 1.8 μm) with linear gradient elution of methanol and water in 8 min. Quantitative analysis was carried out under selective ion monitoring mode. All of the sesquiterpene lactones showed good linearity (R 2 ≥ 0.9949), repeatability (relative standard deviations < 4.66%), and intra- and interday precisions (relative standard deviations < 4.52%) with an accuracy of 95.24-104.84%. The recoveries measured at three concentration levels varied from 95.07 to 104.87% with relative standard deviations less than 4.9%. The limit of detection and limit of quantitation for this method were 0.89-5.05 and 1.12-44.33 ng/mL, respectively. The results showed that the contents of sesquiterpene lactones varied significantly in the Jerusalem artichoke leaf samples from different areas. Among them, the content of sesquiterpene lactones in the sample collected from Dalian, Liaoning province was the highest and the early flowering period was considered to be the optimal harvest time. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Identification of AB-FUBINACA metabolites in authentic urine samples suitable as urinary markers of drug intake using liquid chromatography quadrupole tandem time of flight mass spectrometry.

PubMed

Vikingsson, Svante; Gréen, Henrik; Brinkhagen, Linda; Mukhtar, Shahzabe; Josefsson, Martin

2016-09-01

Synthetic cannabinoids are a group of psychoactive drugs presently widespread among drug users in Europe. Analytical methods to measure these compounds in urine are in demand as urine is a preferred matrix for drug testing. For most synthetic cannabinoids, the parent compounds are rarely detected in urine. Therefore urinary metabolites are needed as markers of drug intake. AB-FUBINACA was one of the top three synthetic cannabinoids most frequently found in seizures and toxicological drug screening in Sweden (2013-2014). Drug abuse is also reported from several other countries such as the USA and Japan. In this study, 28 authentic case samples were used to identify urinary markers of AB-FUBINACA intake using liquid chromatography quadrupole tandem time of flight mass spectrometry and human liver microsomes. Three metabolites suitable as markers of drug intake were identified and at least two of them were detected in all but one case. In total, 15 urinary metabolites of AB-FUBINACA were reported, including hydrolxylations on the indazole ring and the amino-oxobutane moiety, dealkylations and hydrolysis of the primary amide. No modifications on the fluorobenzyl side-chain were observed. The parent compound was detected in 54% of the case samples. Also, after three hours of incubation with human liver microsomes, 77% of the signal from the parent compound remained. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

Indirect enantioseparation of fluoxetine in mouse serum by derivatization with 1R-(-)-menthyl chloroformate followed by ultra high performance liquid chromatography and quadrupole time-of-flight mass spectrometry.

PubMed

Zhao, Jing; Jin, Yan; Shin, Yujin; Jeong, Kyung Min; Lee, Jeongmi

2016-03-01

Here we describe a simple and sensitive analytical method for the enantioselective quantification of fluoxetine in mouse serum using ultra high performance liquid chromatography with quadrupole time-of-flight mass spectrometry. The sample preparation method included a simple deproteinization with acetonitrile in 50 μL of serum, followed by derivatization of the extracts in 50 μL of 2 mM 1R-(-)-menthyl chloroformate at 45ºC for 55 min. These conditions were statistically optimized through response surface methodology using a central composite design. Under the optimized conditions, neither racemization nor kinetic resolution occurred. The derivatized diastereomers were readily resolved on a conventional sub-2 μm C18 column under a simple gradient elution of aqueous methanol containing 0.1% formic acid. The established method was validated and found to be linear, precise, and accurate over the concentration range of 5.0-1000.0 ng/mL for both R and S enantiomers (r(2) > 0.993). Stability tests of the prepared samples at three different concentration levels showed that the R- and S-fluoxetine derivatives were relatively stable for 48 h. No significant matrix effects were observed. Last, the developed method was successfully used for enantiomeric analysis of real serum samples collected at a number of time points from mice administered with racemic fluoxetine. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Concerns about Quadrupole ICP-MS Lead Isotopic Data and Interpretations in the Environment and Health Fields

PubMed Central

Gulson, Brian; Manton, William; Rabinowitz, Michael

2018-01-01

There has been a massive increase in recent years of the use of lead (Pb) isotopes in attempts to better understand sources and pathways of Pb in the environment and in man or experimental animals. Unfortunately, there have been many cases where the quality of the isotopic data, especially that obtained by quadrupole inductively coupled plasma mass spectrometry (Q-ICP-MS), are questionable, resulting in questionable identification of potential sources, which, in turn, impacts study interpretation and conclusions. We present several cases where the isotopic data have compromised interpretation because of the use of only the major isotopes 208Pb/206Pb and 207Pb/206Pb, or their graphing in other combinations. We also present some examples comparing high precision data from thermal ionization (TIMS) or multi-collector plasma mass spectrometry (MC-ICP-MS) to illustrate the deficiency in the Q-ICP-MS data. In addition, we present cases where Pb isotopic ratios measured on Q-ICP-MS are virtually impossible for terrestrial samples. We also evaluate the Pb isotopic data for rat studies, which had concluded that Pb isotopic fractionation occurs between different organs and suggest that this notion of biological fractionation of Pb as an explanation for isotopic differences is not valid. Overall, the brief review of these case studies shows that Q-ICP-MS as commonly practiced is not a suitable technique for precise and accurate Pb isotopic analysis in the environment and health fields. PMID:29641487

Direct analysis of volatile organic compounds in foods by headspace extraction atmospheric pressure chemical ionisation mass spectrometry.

PubMed

Perez-Hurtado, P; Palmer, E; Owen, T; Aldcroft, C; Allen, M H; Jones, J; Creaser, C S; Lindley, M R; Turner, M A; Reynolds, J C

2017-11-30

The rapid screening of volatile organic compounds (VOCs) by direct analysis has potential applications in the areas of food and flavour science. Currently, the technique of choice for VOC analysis is gas chromatography/mass spectrometry (GC/MS). However, the long chromatographic run times and elaborate sample preparation associated with this technique have led a movement towards direct analysis techniques, such as selected ion flow tube mass spectrometry (SIFT-MS), proton transfer reaction mass spectrometry (PTR-MS) and electronic noses. The work presented here describes the design and construction of a Venturi jet-pump-based modification for a compact mass spectrometer which enables the direct introduction of volatiles for qualitative and quantitative analysis. Volatile organic compounds were extracted from the headspace of heated vials into the atmospheric pressure chemical ionization source of a quadrupole mass spectrometer using a Venturi pump. Samples were analysed directly with no prior sample preparation. Principal component analysis (PCA) was used to differentiate between different classes of samples. The interface is shown to be able to routinely detect problem analytes such as fatty acids and biogenic amines without the requirement of a derivatisation step, and is shown to be able to discriminate between four different varieties of cheese with good intra and inter-day reproducibility using an unsupervised PCA model. Quantitative analysis is demonstrated using indole standards with limits of detection and quantification of 0.395 μg/mL and 1.316 μg/mL, respectively. The described methodology can routinely detect highly reactive analytes such as volatile fatty acids and diamines without the need for a derivatisation step or lengthy chromatographic separations. The capability of the system was demonstrated by discriminating between different varieties of cheese and monitoring the spoilage of meats. © 2017 The Authors. Rapid Communications in Mass Spectrometry Published by John Wiley & Sons Ltd.

Diagnostics of capacitively-coupled hydrocarbon plasmas for deposition of diamond-like carbon films using quadrupole mass spectrometry and Langmuir probe

NASA Astrophysics Data System (ADS)

Oda, Akinori; Fukai, Shun; Kousaka, Hiroyuki; Ohta, Takayuki

2015-09-01

Diamond-like carbon (DLC) films are the hydrogenated amorphous carbon films, which contains a mixture of sp2- and sp3-bonded carbon. The DLC films have been widely used for various applications, such as automotive, semiconductors, medical devices, since have excellent material properties in lower friction, higher chemical stability, higher hardness, higher wear resistance. Until now, numerous investigations on the DLC films using plasma assisted chemical vapor deposition have been done. For precise control of coating technique of DLC films, it is enormously important to clarify the fundamental properties in hydrocarbon plasmas, as a source of hydrocarbon ions and radicals. In this paper, the fundamental properties in a low pressure radio-frequency hydrocarbon (Ar/CH4 (1 %) gas mixture) plasmas have been diagnosed using a quadrupole mass spectrometer (HIDEN ANARYTICAL Ltd., EQP-300) and Langmuir probe system (HIDEN ANARYTICAL Ltd., ESPion). This work was partly supported by KAKENHI (No.26420247), and a ``Grant for Advanced Industrial Technology Development (No.11B06004d)'' in 2011 from the New Energy and Industrial Technology Development Organization (NEDO) of Japan.

Monitoring protein glycation by electrospray ionization (ESI) quadrupole time-of-flight (Q-TOF) mass spectrometer.

PubMed

Akıllıoğlu, H Gül; Çelikbıçak, Ömür; Salih, Bekir; Gökmen, Vural

2017-02-15

In this study electrospray ionization quadrupole time-of-flight (ESI-Q-TOF) mass spectrometry was used to investigate protein glycation. The glycated species of cytochrome C, lysozyme, and β-casein formed during glycation with d-glucose were identified and monitored in binary systems heated at 70°C under dry and aqueous conditions. Cytochrome C had multiple charges in non-glycated state, primarily changing from +13 to +17 positive charges, whereas β-casein had charge states up to +30. Upon heating with glucose at 70°C in aqueous state, attachment of one glucose molecule onto proteins was observed in each charge state. However, heating in dry state caused much more glucose attachment, leading to the formation of multiple glycoforms of proteins. By using ESI-QTOF-MS technique, formation of glycated cytochrome C containing up to 12 glucose moieties were observed, while glycated species containing 6 and 8 glucose moieties were observed for lysozyme and β-casein, respectively in various heating conditions. Copyright © 2016 Elsevier Ltd. All rights reserved.

Measurement of stable isotopic enrichment and concentration of long-chain fatty acyl-carnitines in tissue by HPLC-MS.

PubMed

Sun, Dayong; Cree, Melanie G; Zhang, Xiao-Jun; Bøersheim, Elisabet; Wolfe, Robert R

2006-02-01

We have developed a new method for the simultaneous measurements of stable isotopic tracer enrichments and concentrations of individual long-chain fatty acyl-carnitines in muscle tissue using ion-pairing high-performance liquid chromatography-electrospray ionization quadrupole mass spectrometry in the selected ion monitoring (SIM) mode. Long-chain fatty acyl-carnitines were extracted from frozen muscle tissue samples by acetonitrile/methanol. Baseline separation was achieved by reverse-phase HPLC in the presence of the volatile ion-pairing reagent heptafluorobutyric acid. The SIM capability of a single quadrupole mass analyzer allows further separation of the ions of interest from the sample matrixes, providing very clean total and selected ion chromatograms that can be used to calculate the stable isotopic tracer enrichment and concentration of long-chain fatty acyl-carnitines in a single analysis. The combination of these two separation techniques greatly simplifies the sample preparation procedure and increases the detection sensitivity. Applying this protocol to biological muscle samples proves it to be a very sensitive, accurate, and precise analytical tool.

Determination of glutathione in spruce needles by liquid chromatography/tandem mass spectrometry.

PubMed

Gucek, Marjan; Makuc, Simon; Mlakar, Anita; Bericnik-Vrbovsek, Julija; Marsel, Joze

2002-01-01

For the determination of glutathione (GSH) and its oxidized form (GSSG) in spruce needles their electrospray mass and MS/MS spectra were recorded with an ion trap mass spectrometer (ITMS, LCQ, Finnigan) and a triple stage quadrupole mass spectrometer (TSQ, Quattro II, Micromass). A study of the stability of GSH in aqueous solutions shows the presence of dimeric and trimeric forms of GSH, as well as GSSG, GSH-sulfonate and GSH-sulfinic acid. The same components were also found in extracts of spruce needles. We developed an assay which is suitable for monitoring low concentrations of GSH and similar compounds in plant tissues, employing the sensitivity and specificity of LC/MS/MS. Preliminary results on the mass spectrometric determination of GSH in spruce needles are given. Copyright 2002 John Wiley & Sons, Ltd.

Discriminating precursors of common fragments for large-scale metabolite profiling by triple quadrupole mass spectrometry.

PubMed

Nikolskiy, Igor; Siuzdak, Gary; Patti, Gary J

2015-06-15

The goal of large-scale metabolite profiling is to compare the relative concentrations of as many metabolites extracted from biological samples as possible. This is typically accomplished by measuring the abundances of thousands of ions with high-resolution and high mass accuracy mass spectrometers. Although the data from these instruments provide a comprehensive fingerprint of each sample, identifying the structures of the thousands of detected ions is still challenging and time intensive. An alternative, less-comprehensive approach is to use triple quadrupole (QqQ) mass spectrometry to analyze predetermined sets of metabolites (typically fewer than several hundred). This is done using authentic standards to develop QqQ experiments that specifically detect only the targeted metabolites, with the advantage that the need for ion identification after profiling is eliminated. Here, we propose a framework to extend the application of QqQ mass spectrometers to large-scale metabolite profiling. We aim to provide a foundation for designing QqQ multiple reaction monitoring (MRM) experiments for each of the 82 696 metabolites in the METLIN metabolite database. First, we identify common fragmentation products from the experimental fragmentation data in METLIN. Then, we model the likelihoods of each precursor structure in METLIN producing each common fragmentation product. With these likelihood estimates, we select ensembles of common fragmentation products that minimize our uncertainty about metabolite identities. We demonstrate encouraging performance and, based on our results, we suggest how our method can be integrated with future work to develop large-scale MRM experiments. Our predictions, Supplementary results, and the code for estimating likelihoods and selecting ensembles of fragmentation reactions are made available on the lab website at http://pattilab.wustl.edu/FragPred. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

A versatile triple radiofrequency quadrupole system for cooling, mass separation and bunching of exotic nuclei

NASA Astrophysics Data System (ADS)

Haettner, Emma; Plaß, Wolfgang R.; Czok, Ulrich; Dickel, Timo; Geissel, Hans; Kinsel, Wadim; Petrick, Martin; Schäfer, Thorsten; Scheidenberger, Christoph

2018-02-01

The combination of in-flight separation with a gas-filled stopping cell has opened a new field for experiments with exotic nuclei. For instance, at the SHIP/SHIPTRAP facility at GSI in Darmstadt high-precision mass measurements of rare nuclei have been successfully performed. In order to extend the reach of SHIPTRAP to exotic nuclei that are produced together with high rates of unwanted reaction products, a novel compact radio frequency quadrupole (RFQ) system has been developed. It implements ion cooling, identification and separation according to mass numbers and bunching capabilities. The system has a total length of one meter only and consists of an RFQ cooler, an RFQ mass filter and an RFQ buncher. A mass resolving power (FWHM) of 240 at a transmission efficiency of 90% has been achieved. The suppression of contaminants from neighboring masses by more than four orders of magnitude has been demonstrated at rates exceeding 106 ions/s. A longitudinal emittance of 0.45 eV μs has been achieved with the RFQ buncher, which will enable improved time-of-flight mass spectrometry downstream of the device. With this triple RFQ system the measurement of e.g. N= Z nuclides in the region up to tin will become possible at SHIPTRAP. The technology is also well suited for other rare-isotope facilities with experimental setups behind a stopping cell, such as the fragment separator FRS with the FRS Ion Catcher at GSI.

Selective-Reagent-Ionization Mass Spectrometry: New Prospects for Atmospheric Research

NASA Astrophysics Data System (ADS)

Sulzer, Philipp; Jordan, Alfons; Hartungen, Eugen; Hanel, Gernot; Jürschik, Simone; Herbig, Jens; Märk, Lukas; Märk, Tilmann D.

2014-05-01

Proton-Transfer-Reaction Mass Spectrometry (PTR-MS), which was introduced to the scientific community in the 1990's, has quickly evolved into a well-established technology for atmospheric research and environmental chemistry [1]. Advantages of PTR-MS are i) high sensitivities of several hundred cps/ppbv, ii) detection limits at or below the pptv level, iii) direct injection sampling (i.e. no sample preparation), iv) response times in the 100 ms regime and v) online quantification. However, one drawback is a somehow limited selectivity, as in case of quadrupole mass filter based instruments only information about nominal m/z are available. In Time-Of-Flight (TOF) mass analyzer based instruments selectivity is drastically increased by a high mass resolution of up to 8000 m/Δm, but e.g. isomers still cannot be separated. In 2009 we introduced an advanced version of PTR-MS, which permits switching the reagent ions from H3O+ to NO+ and O2+, respectively [2]. This novel type of instrumentation was called Selective-Reagent-Ionization Mass Spectrometry (SRI-MS) and has been successfully used to separate isomers, e.g. the biogenic compounds isoprene and 2-methyl-3-buten-2-ol as shown by Karl et al. [3]. Switching the reagent ions dramatically increases selectivity and thus applicability of SRI-MS in atmospheric research. Here we report on the latest results utilizing an even more advanced embodiment of SRI-MS enabling the use of the additional reagent ions Kr+ and Xe+ [4]. With this technology important atmospheric compounds, such as CO2, CO, CH4, O2, etc. can be quantified and selectivity is increased even further. We present comparison data between diesel and gasoline car exhaust gases and quantitative data on indoor air for these compounds, which are not detectable with classical PTR-MS. Additionally, we show very recent examples of isomers which cannot be separated with PTR-MS but can clearly be distinguished with SRI-MS. Finally, we give an overview of ongoing SRI-MS developments, which include TOF based instruments with increased sensitivity of one order of magnitude (i.e. in the 103 cps/ppbv regime) by means of using a quadrupole ion guide between the drift tube and the TOF analyzer. It is expected that these developments will have a serious impact in atmospheric research, because increased sensitivity implies reduced measurement times and thus, e.g. even more accurate flux measurements. References [1] J. de Gouw, C. Warneke, T. Karl, G. Eerdekens, C. van der Veen, R. Fall, Mass Spectrometry Reviews, 26 (2007), 223-257. [2] A. Jordan, S. Haidacher, G. Hanel, E. Hartungen, J. Herbig, L. Märk, R. Schottkowsky, H. Seehauser, P. Sulzer, T.D. Märk, International Journal of Mass Spectrometry, 286 (2009), 32 - 38. [3] T. Karl, A. Hansel, L. Cappellin, L. Kaser, I. Herdlinger-Blatt, W. Jud, Atmospheric Chemistry and Physics, 12/24 (2012), 11877-11884. [4] P. Sulzer, A. Edtbauer, E. Hartungen, S. Juerschik, A. Jordan, G. Hanel, S. Feil, S. Jaksch, L. Märk, T.D. Märk, International Journal of Mass Spectrometry, 321 (2012), 66-70. Acknowledgement We acknowledge financial support by the Austrian Research Promotion Agency (FFG), Wien.

Simultaneous Qualitative and Quantitative Analyses of Triterpenoids in Ilex pubescens by Ultra-High-Performance Liquid Chromatography Coupled with Quadrupole Time-of-Flight Mass Spectrometry.

PubMed

Cao, Di; Wang, Qing; Jin, Jing; Qiu, Maosong; Zhou, Lian; Zhou, Xinghong; Li, Hui; Zhao, Zhongxiang

2018-03-01

Ilex pubescens Hook et Arn mainly contains triterpenoids that possess antithrombotic, anti-inflammatory and analgesic effects. Quantitative and qualitative analyses of the triterpenoids in I. pubescens can be useful for determining the authenticity and quality of raw materials and guiding its clinical preparation. To establish a method for rapid and comprehensive analysis of triterpenoids in I. pubescens using ultra-high-performance liquid chromatography coupled to electrospray ionisation and quadrupole time-of-flight-mass spectrometry (UPLC-ESI-QTOF-MS), which will also be applied to evaluate the contents of nine triterpenoids among root, root heartwood and root bark of I. pubescens to judge the value of the root bark to avoid wastage. UPLC-ESI-QTOF-MS data from the extracts of I. pubescens in negative mode were analysed using Peakview and Masterview software that provided molecular weight, mass errors, isotope pattern fit and MS/MS fragments for the identification of triterpenoids. The quantification of nine investigated compounds of I. pubescens was accomplished using MultiQuant software. A total of 33 triterpenoids, five phenolic acids, two lignans and a flavonol were characterised in only 14 min. The total content of the nine compounds in the root bark was generally slightly higher than that of the root and root heartwood, which has not been reported before. The developed UPLC-ESI-QTOF-MS method was proven to be rapid and comprehensive for simultaneous qualitative and quantitative analyses of the characteristic triterpenoids in I. pubescens. The results may provide a basis for holistic quality control and metabolic studies of I. pubescens, as well as serve as a reference for the analysis of other Ilex plants. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Determination of perfluorinated carboxylic acids in fish fillet by micro-solid phase extraction, followed by liquid chromatography-triple quadrupole mass spectrometry.

PubMed

Lashgari, Maryam; Lee, Hian Kee

2014-11-21

In the current study, a simple, fast and efficient combination of protein precipitation and micro-solid phase extraction (μ-SPE) followed by liquid chromatography-triple quadrupole tandem mass spectrometry (LC-MS/MS) was developed for the determination of perfluorinated carboxylic acids (PFCAs) in fish fillet. Ten PFCAs with different hydrocarbon chain lengths (C5-C14) were analysed simultaneously using this method. Protein precipitation by acetonitrile and μ-SPE by surfactant-incorporated ordered mesoporous silica were applied to the extraction and concentration of the PFCAs as well as for removal of interferences. Determination of the PFCAs was carried out by LC-MS/MS in negative electrospray ionization mode. MS/MS parameters were optimized for multiple reaction monitoring of the analytes. (13)C mass labelled PFOA as a stable-isotopic internal standard, was used for calibration. The detection limits of the method ranged from 0.97 ng/g to 2.7 ng/g, with a relative standard deviation of between 5.4 and 13.5. The recoveries were evaluated for each analyte and were ranged from 77% to 120%. The t-test at 95% confidence level showed that for all the analytes, the relative recoveries did not depend on their concentrations in the explored concentration range. The effect of the matrix on MS signals (suppression or enhancement) was also evaluated. Contamination at low levels was detected for some analytes in the fish samples. The protective role of the polypropylene membrane used in μ-SPE in the elimination of matrix effects was evaluated by parallel experiments in classical dispersive solid phase extraction. The results evidently showed that the polypropylene membrane was significantly effective in reducing matrix effects. Copyright © 2014 Elsevier B.V. All rights reserved.

Solid-phase extraction followed by liquid chromatography quadrupole time-of-flight tandem mass spectrometry for the selective determination of fungicides in wine samples.

PubMed

Fontana, A R; Rodríguez, I; Ramil, M; Altamirano, J C; Cela, R

2011-04-22

In this work, a reliable and selective procedure for the determination of thirteen fungicides in red and white wine samples is proposed. Solid-phase extraction (SPE) and liquid chromatography (LC) tandem mass spectrometry (MS/MS), based on a hybrid quadrupole time-of-flight (QTOF) system, were used as sample preparation and determination techniques, respectively. Extraction and purification of target analytes was carried out simultaneously by using a reversed-phase Oasis HLB (200mg) SPE cartridge combined with acetonitrile as elution solvent. Fungicides were determined operating the electrospray source in the positive ionization mode, with MS/MS conditions adjusted to obtain at least two intense product ions per compound, or registering two transitions per species when a single product was noticed. High selective MS/MS chromatograms were extracted using a mass window of 20 ppms for each product ion. Considering external calibration as quantification technique, the overall recoveries (accuracy) of the procedure ranged between 81% and 114% for red and white wine samples (10-20 mL), spiked at different concentrations between 5 and 100 ng mL(-1). Relative standard deviations of the above data stayed below 12% and the limits of quantification (LOQs) of the method, calculated for 10 mL of wine, varied between 0.1 ng mL(-1) for cyprodinil (CYP) and 0.7 ng mL(-1) for myclobutanil (MYC). The optimized method was applied to seventeen commercial wines produced in Spain and obtained from local supermarkets. Nine fungicides were determined, at levels above the LOQs of the method, in the above samples. The maximum concentrations and the highest occurrence frequencies corresponded to metalaxyl (MET) and iprovalicarb (IPR). Copyright © 2011 Elsevier B.V. All rights reserved.

Rapid wide-scope screening of drugs of abuse, prescription drugs with potential for abuse and their metabolites in influent and effluent urban wastewater by ultrahigh pressure liquid chromatography-quadrupole-time-of-flight-mass spectrometry.

PubMed

Hernández, Félix; Bijlsma, Lubertus; Sancho, Juan V; Díaz, Ramon; Ibáñez, María

2011-01-17

This work illustrates the potential of hybrid quadrupole-time-of-flight mass spectrometry (QTOF MS) coupled to ultrahigh pressure liquid chromatography (UHPLC) to investigate the presence of drugs of abuse in wastewater. After solid-phase extraction with Oasis MCX cartridges, seventy-six illicit drugs, prescription drugs with potential for abuse, and metabolites were investigated in the samples by TOF MS using electrospray interface under positive ionization mode, with MS data acquired over an m/z range of 50-1000Da. For 11 compounds, reference standards were available, and experimental data (e.g., retention time and fragmentation data) could be obtained, facilitating a more confident identification. The use of a QTOF instrument enabled the simultaneous application of two acquisition functions with different collision energies: a low energy (LE) function, where none or poor fragmentation took place, and a high energy (HE) function, where fragmentation in the collision cell was promoted. This approach, known as MS(E), enabled the simultaneous acquisition of full-spectrum accurate mass data of both protonated molecules and fragment ions in a single injection, providing relevant information that facilitates the rapid detection and reliable identification of these emerging contaminants in the sample matrices analyzed. In addition, isomeric compounds, like the opiates, morphine and norcodeine, could be discriminated by their specific fragments observed in HE TOF MS spectra, without the need of reference standards. UHPLC-QTOF MS was proven to be a powerful and efficient technique for rapid wide-scope screening and identification of many relevant drugs in complex matrices, such as influent and effluent urban wastewater. Copyright © 2010 Elsevier B.V. All rights reserved.

Use of liquid chromatography coupled to quadrupole time-of-flight mass spectrometry to investigate pesticide residues in fruits.

PubMed

Grimalt, Susana; Pozo, Oscar J; Sancho, Juan V; Hernández, Félix

2007-04-01

In this paper, the potential of coupling liquid chromatography with hybrid quadrupole time-of-flight mass spectrometry (LC-QTOF) for the determination of pesticides in a variety of fruit samples (orange peel and flesh, banana skin and flesh, strawberry and pear) has been explored. The quantitative application at residue levels has been proven for two insecticides (buprofezin and hexythiazox), which were satisfactorily determined at three concentration levels, 0.1, 1, and 5 mg/kg, obtaining a suitable linearity range (correlation coefficient>0.99) of more than 2 orders of magnitude. Satisfactory recoveries have been obtained for both compounds at the three levels tested in all sample matrices, with lowest calibration levels (LCL) of 0.075 and 0.01 mg/kg. The excellent potential of QTOF for identification purposes is illustrated by the high number of identification points (IPs) earned, up to 21, at the highest concentration of 5 mg/kg, or between 11 and 21 at the 0.1 and 1 mg/kg levels. The application of LC-QTOF MS to real samples revealed the presence of several positives at concentrations close to the LCL, all of which were confirmed with more than 11 IPs. The potential of QTOF for elucidation of nontarget analytes has also been demonstrated by the finding of one transformation product (TP) of buprofezin in a banana skin sample. This TP was identified by obtaining the full scan product ion spectra at different collision energies with acceptable accurate mass deviation. The work performed in this paper illustrates the suitability and excellent confirmatory potential of LC-QTOF MS for pesticides residues analysis in food samples.

Determination of homocysteine in human saliva by liquid chromatography and electrospray ionization quadrupole time-of-flight mass spectrometry: profiles in healthy adults.

PubMed

Abaye, Daniel A; Nielsen, Birthe; Boateng, Joshua S

2013-12-01

Homocysteine (Hcys) is a non-essential amino acid associated with a range of diseased and abnormal metabolic conditions. Hcys concentration in saliva is routinely determined by enzyme assays, which are broadly specific, but can be expensive and suffer from cross-reactivity. Total Hcys (tHcys) concentrations in eight healthy adults were determined to establish the inter-day variation during resting, normal and intensive physical activity, using the more sensitive analytical techniques of liquid chromatography and tandem mass spectrometry without prior derivatization. Saliva (~ 1.5 mL) was collected over four days; early morning (EA), normal activity (NA) and during physical activity (PA). Samples were processed by disulphide reduction, acetonitrile precipitation and then centrifugation-filtration. Extracts were chromatographically resolved and analysed on a quadrupole time- of-flight (QToF) mass spectrometer. The protonated [M+H]+, m/z 136.101 and product ([M+H]+- HCOOH) m/z 90.103 ions were then monitored against an internal standard (13CHcys) and external set of calibration standards. Mean tHcys concentration for the whole group, including exercise was 6.6 ± 8.0 (range 0.2 - 29.6 nmol/mL). Overall, concentration of tHcys was greater in males than the females but not significantly (p > 0.05). The mean EA concentration was significantly (p < 0.05) greater than NA for both males (p = 0340) and females (p = 0.0045). There were large within-subject variations (coefficient of variation; CV%; 24% to 103%). The limits of detection (LOD) and quantification (LOQ) were 0.07 and 0.22 nmol/mL, respectively. The procedure potentially provides a convenient means of analyzing salivary Hcys as a diagnostic disease marker.

Simultaneous quantification of 17 trace elements in blood by dynamic reaction cell inductively coupled plasma mass spectrometry (DRC-ICP-MS) equipped with a high-efficiency sample introduction system.

PubMed

D'Ilio, S; Violante, N; Di Gregorio, M; Senofonte, O; Petrucci, F

2006-10-10

A quadrupole inductively coupled plasma mass spectrometer (Q-ICP-MS) equipped with a dynamic reaction cell (DRC) and coupled with a desolvating nebulization system (APEX-IR) was employed to determine 17 elements (Al, As, Ba, Cd, Co, Cr, Li, Mn, Mo, Ni, Pb, Sb, Se, Sn, Sr, V, and Zr) in blood samples. Ammonia (for Al, Cr, Mn, and V) and O2 (for As and Se) were used as reacting gases. Selection of the best flow rate of the gases and optimization of the quadrupole dynamic bandpass tuning parameter (RPq) were carried out, using digested blood diluted 1+9 with deionized water and spiked with 1 microg L(-1) of Al, Cr, Mn, V and 5 microgL(-1) of As and Se. Detection limits were determined in digested blood using the 3sigma criterion. The desolvating system allowed a sufficient sensitivity to be achieved to determine elements at levels of ng L(-1) without detriment of signal stability. The accuracy of the method was tested with the whole blood certified reference material (CRM), certified for Al, As, Cd, Co, Cr, Mn, Mo, Ni, Pb, Sb, Se, and V, and with indicative values for Ba, Li, Sn, Sr, and Zr. The addition calibration approach was chosen for analysis. In order to confirm the DRC data, samples were also analyzed by means of sector field inductively coupled plasma mass spectrometry (SF-ICP-MS), operating in medium (m/Deltam=4000) and high (m/Deltam=10,000) resolution mode and achieving a good agreement between the two techniques.

The new ClusterTrap setup

NASA Astrophysics Data System (ADS)

Martinez, F.; Marx, G.; Schweikhard, L.; Vass, A.; Ziegler, F.

2011-07-01

ClusterTrap has been designed to investigate properties of atomic clusters in the gas phase with particular emphasis on the dependence on the cluster size and charge state. The combination of cluster source, Penning trap and time-of-flight mass spectrometry allows a variety of experimental schemes including collision-induced dissociation, photo-dissociation, further ionization by electron impact, and electron attachment. Due to the storage capability of the trap extended-delay reaction experiments can be performed. Several recent modifications have resulted in an improved setup. In particular, an electrostatic quadrupole deflector allows the coupling of several sources or detectors to the Penning trap. Furthermore, a linear radio-frequency quadrupole trap has been added for accumulation and ion bunching and by switching the potential of a drift tube the kinetic energy of the cluster ions can be adjusted on their way towards or from the Penning trap. Recently, experiments on multiply negatively charged clusters have been resumed.

Comparison and characterization of soybean and sunflower lecithins used for chocolate production by high-performance thin-layer chromatography with fluorescence detection and electrospray mass spectrometry.

PubMed

Krüger, Stephanie; Bürmann, Laura; Morlock, Gertrud E

2015-03-25

The scarce availability of nongenetically modified soybeans on the world market represents a growing problem for food manufacturers. Hence, in this study the effects of substituting soybean with sunflower lecithin were investigated with regard to chocolate production. The glycerophospholipid pattern of the different lecithin samples was investigated by high-performance thin-layer chromatography fluorescence detection (HPTLC-FLD) and by HPTLC-positive ion electrospray ionization mass spectrometry (ESI(+)-MS) via the TLC-MS Interface and by scanning HPTLC-matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOFMS). Especially, the contents of phosphatidylcholine (PC) and phosphatidylethanolamine (PE) were of interest due to the influencing effects of these two glycerophospholipids on the rheological parameters of chocolate production. The lecithin substitution led to only slight differences in the rheological parameters of milk and dark chocolate. Limits of detection (LODs) and limits of quantification (LOQs) of seven glycerophospholipids were studied for three detection modes. Mean LODs ranged from 8 to 40 mg/kg for HPTLC-FLD and, using a single-quadrupole MS, from 10 to 280 mg/kg for HPTLC-ESI(+)-MS as well as from 15 to 310 mg/kg for HPTLC-FLD-ESI(+)-MS recorded after derivatization with the primuline reagent.

Characterization of the limonene oxidation products with liquid chromatography coupled to the tandem mass spectrometry

NASA Astrophysics Data System (ADS)

Witkowski, Bartłomiej; Gierczak, Tomasz

2017-04-01

Composition of the secondary organic aerosol (SOA) generated during ozonolysis of limonene was investigated with liquid chromatography coupled to the negative electrospray ionization (ESI), quadrupole tandem mass spectrometry (MS/MS) as well as high resolution Time-of-Flight mass spectrometry. Aerosol was generated in the flow-tube reactor. HR-MS/MS analysis allowed for proposing structures for the several up-to-date unknown limonene oxidation products. In addition to the low MW limonene oxidation products, significant quantities of oligomers characterized by elemental compositions: C19H30O5, C18H28O6, C19H28O7, C19H30O7 and C20H34O9 were detected in the SOA samples. It was concluded that these compounds are most likely esters, aldol reaction products and/or hemiacetals. In addition to detailed study of the limonene oxidation products, the reaction time as well as initial ozone concentration impact on the limonene SOA composition was investigated. The relative intensities of the two esters of the limonic acid and 7-hydroxy limononic acid increased as a result of lowering the initial ozone concentration and shortening the reaction time, indicating that esterification may be an important oligomerization pathway during limonene SOA formation.

Ultra high performance liquid chromatography with tandem mass spectrometry screening and mutagenicity evaluation of photodegradation products of Carmoisine (E122) dye in a beverage.

PubMed

Yamjala, Karthik; Nainar, Meyyanathan Subramania; Ramisetti, Nageswara Rao

2016-06-01

The present study deals with the separation and identification of the photodegradation products formed when a commercial soft drink containing Carmoisine (E122) dye was exposed to natural sunlight. An ultra high performance liquid chromatography with quadrupole time-of-flight tandem mass spectrometry method was developed and validated to identify the unknown species of E122. During the study, it was observed that the dye decolourizes rapidly in beverage when compared to model standard solutions. The sunlight irradiation of beverage containing E122 resulted in four photodegradation products as identified by nontarget screening using high-resolution tandem mass spectrometry. Accurate mass measurements were used to identify the elemental composition, and to elucidate the structures of degradation products a software tool was employed. The degradation products (P1-P4) were formed from the interactions of the dye with other ingredients present in the beverage. The toxicity of the degradation products was evaluated on five bacterial strains (TA98, TA100, TA1535, TA1537, and WP2 uvrA pKM101) through an in vitro bacterial reverse mutation assay. The photodegradation products showed strong mutagenic potential in strain TA 100 (without S9) as detected by the Ames assay. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Development of extractive electrospray ionization ion trap mass spectrometry for in vivo breath analysis.

PubMed

Ding, Jianhua; Yang, Shuiping; Liang, Dapeng; Chen, Huanwen; Wu, Zhuanzhang; Zhang, Lili; Ren, Yulin

2009-10-01

In metabolomics studies and clinical diagnosis, interest is increasing in the rapid analysis of exhaled breath. In vivo breath analysis offers a unique, unobtrusive, non-invasive method of investigating human metabolism. To analyze breath in vivo, we constructed a novel platform of extractive electrospray ionization (EESI) ion trap mass spectrometry (ITMS) using a home-made EESI source coupled to a linear trap quadrupole mass spectrometer. A reference compound (authentic n-octyl amine) was used to evaluate effects of systematically varying selected characteristics of the EESI source on signal intensity. Under the optimized working conditions, metabolic changes of human bodies were in vivo followed by performing rapid breath analysis using the multi-stage EESI-ITMS tandem mass spectrometry platform. For nicotine, a limit of determination was found to be 0.05 fg mL(-1) (S/N = 3, RSD = 5.0 %, n = 10) for nicotine in aerosol standard samples; the dynamic response range was from 0.0155 pg mL(-1) to 155 pg mL(-1). The concentration of nicotine in the exhaled breath of a regular smoker was in vivo determined to be 5.8 pg mL(-1), without any sample pre-treatment. Our results show that EESI-ITMS is a powerful analytical platform to provide high sensitivity, high specificity and high throughput for semi-quantitative analysis of complex samples in life science, particularly for in vivo metabolomics studies.

Ultra-performance liquid chromatography-tandem mass spectrometry for the determination of atypical antipsychotics and some metabolites in in vitro samples.

PubMed

Li, Kun-Yan; Zhou, Yan-Gang; Ren, Hua-Yi; Wang, Feng; Zhang, Bi-Kui; Li, Huan-De

2007-05-01

The ultra-performance liquid chromatography-electrospray tandem mass spectrometry (UPLC-ESI-MS/MS) method has been developed to perform the determination of quetiapine, perospirone, aripiprazole and quetiapine sulfoxide in in vitro samples in less than 3 min. The UPLC separation was carried out using an Acquity UPLC BEH C18 column (100 mm x 2.1mm i.d., 1.7 microm particle size) that provided high efficiency and resolution in combination with high linear velocities. The UPLC system was coupled to a Waters Micromass Quattro Premier XE tandem quadrupole mass spectrometer. This system permits high-speed data acquisition without peak intensity degradation, and produces sharp and narrow chromatographic peaks (w(h) about 2.5s) of compounds. The determination was performed in multiple reaction monitoring (MRM) mode. The quantification parameters of the developed method were established, obtaining instrumental LODs lower than 0.005 microg/l and a repeatability at a low concentration level lower than 10% CV (n=10). Finally, the method was successfully applied to the analysis of atypical antipsychotics and some metabolites in in vitro samples.

Constructing Proteome Reference Map of the Porcine Jejunal Cell Line (IPEC-J2) by Label-Free Mass Spectrometry.

PubMed

Kim, Sang Hoon; Pajarillo, Edward Alain B; Balolong, Marilen P; Lee, Ji Yoon; Kang, Dae-Kyung

2016-06-28

In this study, the global proteome of the IPEC-J2 cell line was evaluated using ultra-high performance liquid chromatography coupled to a quadrupole Q Exactive™ Orbitrap mass spectrometer. Proteins were isolated from highly confluent IPEC-J2 cells in biological replicates and analyzed by label-free mass spectrometry prior to matching against a porcine genomic dataset. The results identified 1,517 proteins, accounting for 7.35% of all genes in the porcine genome. The highly abundant proteins detected, such as actin, annexin A2, and AHNAK nucleoprotein, are involved in structural integrity, signaling mechanisms, and cellular homeostasis. The high abundance of heat shock proteins indicated their significance in cellular defenses, barrier function, and gut homeostasis. Pathway analysis and annotation using the Kyoto Encyclopedia of Genes and Genomes database resulted in a putative protein network map of the regulation of immunological responses and structural integrity in the cell line. The comprehensive proteome analysis of IPEC-J2 cells provides fundamental insights into overall protein expression and pathway dynamics that might be useful in cell adhesion studies and immunological applications.

Structural elucidation of new urinary tamoxifen metabolites by liquid chromatography quadrupole time-of-flight mass spectrometry.

PubMed

Lu, Jianghai; He, Chunji; He, Genye; Wang, Xiaobing; Xu, Youxuan; Wu, Yun; Dong, Ying; Ouyang, Gangfeng

2014-07-01

In this study, tamoxifen metabolic profiles were investigated carefully. Tamoxifen was administered to two healthy male volunteers and one female patient suffering from breast cancer. Urinary extracts were analyzed by liquid chromatography quadruple time-of-flight mass spectrometry using full scan and targeted MS/MS techniques with accurate mass measurement. Chromatographic peaks for potential metabolites were selected by using the theoretical [M + H](+) as precursor ion in full-scan experiment and m/z 72, 58 or 44 as characteristic product ions for N,N-dimethyl, N-desmethyl and N,N-didesmethyl metabolites in targeted MS/MS experiment, respectively. Tamoxifen and 37 metabolites were detected in extraction study samples. Chemical structures of seven unreported metabolites were elucidated particularly on the basis of fragmentation patterns observed for these metabolites. Several metabolic pathways containing mono- and di-hydroxylation, methoxylation, N-desmethylation, N,N-didesmethylation, oxidation and combinations were suggested. All the metabolites were detected in the urine samples up to 1 week. Copyright © 2014 John Wiley & Sons, Ltd.

Shotgun metabolomic approach based on mass spectrometry for hepatic mitochondria of mice under arsenic exposure.

PubMed

García-Sevillano, M A; García-Barrera, T; Navarro, F; Montero-Lobato, Z; Gómez-Ariza, J L

2015-04-01

Mass spectrometry (MS)-based toxicometabolomics requires analytical approaches for obtaining unbiased metabolic profiles. The present work explores the general application of direct infusion MS using a high mass resolution analyzer (a hybrid systems triple quadrupole-time-of-flight) and a complementary gas chromatography-MS analysis to mitochondria extracts from mouse hepatic cells, emphasizing on mitochondria isolation from hepatic cells with a commercial kit, sample treatment after cell lysis, comprehensive metabolomic analysis and pattern recognition from metabolic profiles. Finally, the metabolomic platform was successfully checked on a case-study based on the exposure experiment of mice Mus musculus to inorganic arsenic during 12 days. Endogenous metabolites alterations were recognized by partial least squares-discriminant analysis. Subsequently, metabolites were identified by combining MS/MS analysis and metabolomics databases. This work reports for the first time the effects of As-exposure on hepatic mitochondria metabolic pathways based on MS, and reveals disturbances in Krebs cycle, β-oxidation pathway, amino acids degradation and perturbations in creatine levels. This non-target analysis provides extensive metabolic information from mitochondrial organelle, which could be applied to toxicology, pharmacology and clinical studies.

Multiresidue analysis of multiclass pesticides and polyaromatic hydrocarbons in fatty fish by gas chromatography tandem mass spectrometry and evaluation of matrix effect.

PubMed

Chatterjee, Niladri S; Utture, Sagar; Banerjee, Kaushik; Ahammed Shabeer, T P; Kamble, Narayan; Mathew, Suseela; Ashok Kumar, K

2016-04-01

This paper reports a selective and sensitive method for multiresidue determination of 119 chemical residues including pesticides and polyaromatic hydrocarbons (PAH) in high fatty fish matrix. The novel sample preparation method involved extraction of the target analytes from homogenized fish meat (5 g) in acetonitrile (15 mL, 1% acetic acid) after three-phase partitioning with hexane (2 mL) and the remaining aqueous layer. An aliquot (1.5 mL) of the acetonitrile layer was aspirated and subjected to two-stage dispersive solid phase extraction (dSPE) cleanup and the residues were finally estimated by gas chromatography mass spectrometry with selected reaction monitoring (GC-MS/MS). The co-eluted matrix components were identified on the basis of their accurate mass by GC with quadrupole time of flight MS. Addition of hexane during extraction and optimized dSPE cleanup significantly minimized the matrix effects. Recoveries at 10, 25 and 50 μg/kg were within 60-120% with associated precision, RSD<11%. Copyright © 2015 Elsevier Ltd. All rights reserved.

Purification of a PHA-like chitin-binding protein from Acacia farnesiana seeds: a time-dependent oligomerization protein.

PubMed

Santi-Gadelha, T; Rocha, B A M; Oliveira, C C; Aragão, K S; Marinho, E S; Gadelha, C A A; Toyama, M H; Pinto, V P T; Nagano, C S; Delatorre, P; Martins, J L; Galvani, F R; Sampaio, A H; Debray, H; Cavada, B S

2008-07-01

A lectin-like protein from the seeds of Acacia farnesiana was isolated from the albumin fraction, characterized, and sequenced by tandem mass spectrometry. The albumin fraction was extracted with 0.5 M NaCl, and the lectin-like protein of A. farnesiana (AFAL) was purified by ion-exchange chromatography (Mono-Q) followed by chromatofocusing. AFAL agglutinated rabbit erythrocytes and did not agglutinate human ABO erythrocytes either native or treated with proteolytic enzymes. In sodium dodecyl sulfate gel electrophoresis under reducing and nonreducing conditions, AFAL separated into two bands with a subunit molecular mass of 35 and 50 kDa. The homogeneity of purified protein was confirmed by chromatofocusing with a pI = 4.0 +/- 0.5. Molecular exclusion chromatography confirmed time-dependent oligomerization in AFAL, in accordance with mass spectrometry analysis, which confers an alteration in AFAL affinity for chitin. The protein sequence was obtained by a liquid chromatography quadrupole time-of-flight experiment and showed that AFAL has 68% and 63% sequence similarity with lectins of Phaseolus vulgaris and Dolichos biflorus, respectively.

From untargeted LC-QTOF analysis to characterisation of opines in abalone adductor muscle: Theory meets practice.

PubMed

Venter, Leonie; Jansen van Rensburg, Peet J; Loots, Du Toit; Vosloo, Andre; Lindeque, Jeremie Zander

2017-12-15

Abalone have a unique ability to use pyruvate, various amino acids and dehydrogenases, to produce opines as means to prevent the accumulation of NADH during anaerobic conditions. In this study, the theoretical masses, formulae and fragment patterns of butylated opines were used to predict which of these compounds could be found in the abalone adductor muscle using untargeted liquid chromatography quadrupole time-of flight-mass spectrometry. These findings were validated using synthesised opine standards. In essence alanopine, lysopine, strombine and tauropine produced in abalone adductor muscle could be characterised using the highest identification confidence levels. Copyright © 2017 Elsevier B.V. All rights reserved.

Rapid quantification of iodopropynyl butylcarbamate as the preservative in cosmetic formulations using high-performance liquid chromatography-electrospray mass spectrometry.

PubMed

Frauen, M; Steinhart, H; Rapp, C; Hintze, U

2001-07-01

A simple, rapid and reproducible method for identification and quantification of iodopropynyl butylcarbamate (IPBC) in different cosmetic formulations is presented. The determination was carried out using a high-performance liquid chromatography (HPLC) procedure on a reversed phase column coupled to a single quadrupole mass spectrometer (MS) via an electrospray ionization (ESI) interface. Detection was performed in the positive selected ion-monitoring mode. In methanol/water extracts from different cosmetic formulations a detection limit between 50 and 100 ng/g could be achieved. A routine analytical procedure could be set up with good quantification reliability (relative standard deviation between 0.9 and 2.9%).

Continued Development of in Situ Geochronology for Planetary Missions

NASA Technical Reports Server (NTRS)

Devismes, D.; Cohen, B. A.

2015-01-01

The instrument 'Potassium (K) Argon Laser Experiment' (KArLE) is developed and designed for in situ absolute dating of rocks on planetary surfaces. It is based on the K-Ar dating method and uses the Laser Induced Breakdown Spectroscopy - Laser Ablation - Quadrupole Mass Spectrometry (LIBSLA- QMS) technique. We use a dedicated interface to combine two instruments similar to SAM of Mars Science Laboratory (for the QMS) and ChemCam (for the LA and LIBS). The prototype has demonstrated that KArLE is a suitable and promising instrument for in situ absolute dating.

Structural Characterisation of Acetogenins from Annona muricata by Supercritical Fluid Chromatography Coupled to High-Resolution Tandem Mass Spectrometry.

PubMed

Laboureur, Laurent; Bonneau, Natacha; Champy, Pierre; Brunelle, Alain; Touboul, David

2017-11-01

Acetogenins are plant polyketides known to be cytotoxic and proposed as antitumor candidates. They are also suspected to be alimentary neurotoxins. Their occurrence as complex mixtures renders their dereplication and structural identification difficult using liquid chromatography coupled to tandem mass spectrometry and efforts are required to improve the methodology. To develop a supercritical fluid chromatography (SFC) high-resolution tandem mass spectrometry method, involving lithium post-column cationisation, for the structural characterisation of Annonaceous acetogenins in crude extracts. The seeds of Annona muricata L. were extracted with methanol. Supercritical fluid chromatography of the extract, using a 2-ethylpyridine stationary phase column, was monitored using a high-resolution quadrupole time-of-flight mass spectrometer. Lithium iodide was added post-column in the make-up solvent. For comparison, the same extract was analysed using high-pressure liquid chromatography coupled to the same mass spectrometer, with a column based on solid core particles. Sensitivity was similar for both HPLC and SFC approaches. Retention behaviour and fragmentation pathways of three different isomer groups are described. A previously unknown group of acetogenins was also evidenced for the first time. The use of SFC-MS/MS allows the reduction of the time of analysis, of environmental impact and an increase in the chromatographic resolution, compared to liquid chromatography. This new methodology enlightened a new group of acetogenins, isomers of montanacin-D. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Optimization of a direct analysis in real time/time-of-flight mass spectrometry method for rapid serum metabolomic fingerprinting.

PubMed

Zhou, Manshui; McDonald, John F; Fernández, Facundo M

2010-01-01

Metabolomic fingerprinting of bodily fluids can reveal the underlying causes of metabolic disorders associated with many diseases, and has thus been recognized as a potential tool for disease diagnosis and prognosis following therapy. Here we report a rapid approach in which direct analysis in real time (DART) coupled with time-of-flight (TOF) mass spectrometry (MS) and hybrid quadrupole TOF (Q-TOF) MS is used as a means for metabolomic fingerprinting of human serum. In this approach, serum samples are first treated to precipitate proteins, and the volatility of the remaining metabolites increased by derivatization, followed by DART MS analysis. Maximum DART MS performance was obtained by optimizing instrumental parameters such as ionizing gas temperature and flow rate for the analysis of identical aliquots of a healthy human serum samples. These variables were observed to have a significant effect on the overall mass range of the metabolites detected as well as the signal-to-noise ratios in DART mass spectra. Each DART run requires only 1.2 min, during which more than 1500 different spectral features are observed in a time-dependent fashion. A repeatability of 4.1% to 4.5% was obtained for the total ion signal using a manual sampling arm. With the appealing features of high-throughput, lack of memory effects, and simplicity, DART MS has shown potential to become an invaluable tool for metabolomic fingerprinting. 2010 American Society for Mass Spectrometry. Published by Elsevier Inc. All rights reserved.

Detection of reactive metabolites using isotope-labeled glutathione trapping and simultaneous neutral loss and precursor ion scanning with ultra-high-pressure liquid chromatography triple quadruple mass spectrometry.

PubMed

Huang, Ke; Huang, Lingyi; van Breemen, Richard B

2015-04-07

Metabolic activation of drugs to electrophilic species is responsible for over 60% of black box warnings and drug withdrawals from the market place in the United States. Reactive metabolite trapping using glutathione (GSH) and analysis using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) or HPLC with high resolution mass spectrometry (mass defect filtering) have enabled screening for metabolic activation to become routine during drug development. However, current MS-based approaches cannot detect all GSH conjugates present in complex mixtures, especially those present in extracts of botanical dietary supplements. To overcome these limitations, a fast triple quadrupole mass spectrometer-based approach was developed that can detect positively and negatively charged GSH conjugates in a single analysis without the need for advanced knowledge of the elemental compositions of potential conjugates and while avoiding false positives. This approach utilized UHPLC instead of HPLC to shorten separation time and enhance sensitivity, incorporated stable-isotope labeled GSH to avoid false positives, and used fast polarity switching electrospray MS/MS to detect GSH conjugates that form positive and/or negative ions. The general new method was then used to test the licorice dietary supplement Glycyrrhiza glabra, which was found to form multiple GSH conjugates upon metabolic activation. Among the GSH conjugates found in the licorice assay were conjugates with isoliquiritigenin and glabridin, which is an irreversible inhibitor of cytochrome P450 enzymes.

A strategy for screening and identifying mycotoxins in herbal medicine using ultra-performance liquid chromatography with tandem quadrupole time-of-flight mass spectrometry.

PubMed

Fang, Lian-xiang; Xiong, Ai-zhen; Wang, Rui; Ji, Shen; Yang, Li; Wang, Zheng-tao

2013-09-01

The objective of this study was to develop an effective strategy for screening and identifying mycotoxins in herbal medicine (HM). Here, Imperatae Rhizoma, a commonly used Chinese herb, was selected as a model HM. A crude drug contaminated with fungi was analyzed by comparing with uncontaminated ones. Ultra-performance LC coupled to tandem quadrupole TOF-MS (UPLC-Q-TOF-MS) with collision energy function was applied to analyze different samples from Imperatae Rhizoma. Then, MarkerLynx(TM) software was employed to screen the excess components in analytes, compared with control samples, and those selected markers were likely to be the metabolites of fungi. Furthermore, each of the accurate masses of the markers obtained from MarkerLynx(TM) was then searched in a mycotoxins/fungal metabolites database established in advance. The molecular formulas with relative mass error between the measured and theoretical mass within 5 ppm were chosen and then applied to MassFragment(TM) analysis for further confirmation of their structures. With the use of this approach, five mycotoxins that have never been reported in HM were identified in contaminated Imperatae Rhizoma. The results demonstrate the potential of UPLC-Q-TOF-MS coupled with the MarkerLynx(TM) software and MassFragment(TM) tool as an efficient and convenient method to screen and identify mycotoxins in herbal materials and aid in the quality control of HM. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Determination of four forms of vitamin B12 and other B vitamins in seawater by liquid chromatography/tandem mass spectrometry.

PubMed

Heal, Katherine R; Carlson, Laura Truxal; Devol, Allan H; Armbrust, E Virginia; Moffett, James W; Stahl, David A; Ingalls, Anitra E

2014-11-30

Vitamin B(12) is an essential nutrient for more than half of surveyed marine algae species, but methods for directly measuring this important cofactor in seawater are limited. Current mass spectrometry methods do not quantify all forms of B(12), potentially missing a significant portion of the B(12) pool. We present a method to measure vitamins B(1), B(2), B(6), B(7) and four forms of B(12) dissolved in seawater. The method entails solid-phase extraction, separation by ultra-performance liquid chromatography, and detection by triple-quadrupole tandem mass spectrometry using stable-isotope-labeled internal standards. We demonstrated the use of this method in the environment by analyzing B(12) concentrations at different depths in the Hood Canal, part of the Puget Sound estuarine system in Washington State. Recovery of vitamin B(12) forms during the preconcentration steps was >71% and the limits of detection were <0.275 pM in seawater. Standard addition calibration curves in three different seawater matrices were used to determine analytical response and to quantify samples from the environment. Hydroxocobalamin was the main form of B(12) in seawater at our field site. We developed a method for quantifying four forms of B(12) in seawater by liquid chromatography/mass spectrometry with the option of simultaneous analysis of vitamins B(1), B(2), B(6), and B(7). We validated the method and demonstrated its application in the field. Copyright © 2014 John Wiley & Sons, Ltd.

Wavelet-Based Peak Detection and a New Charge Inference Procedure for MS/MS Implemented in ProteoWizard’s msConvert

PubMed Central

2015-01-01

We report the implementation of high-quality signal processing algorithms into ProteoWizard, an efficient, open-source software package designed for analyzing proteomics tandem mass spectrometry data. Specifically, a new wavelet-based peak-picker (CantWaiT) and a precursor charge determination algorithm (Turbocharger) have been implemented. These additions into ProteoWizard provide universal tools that are independent of vendor platform for tandem mass spectrometry analyses and have particular utility for intralaboratory studies requiring the advantages of different platforms convergent on a particular workflow or for interlaboratory investigations spanning multiple platforms. We compared results from these tools to those obtained using vendor and commercial software, finding that in all cases our algorithms resulted in a comparable number of identified peptides for simple and complex samples measured on Waters, Agilent, and AB SCIEX quadrupole time-of-flight and Thermo Q-Exactive mass spectrometers. The mass accuracy of matched precursor ions also compared favorably with vendor and commercial tools. Additionally, typical analysis runtimes (∼1–100 ms per MS/MS spectrum) were short enough to enable the practical use of these high-quality signal processing tools for large clinical and research data sets. PMID:25411686

Tandem mass spectrometry characteristics of polyester anions and cations formed by electrospray ionization.

PubMed

Arnould, Mark A; Buehner, Rita W; Wesdemiotis, Chrys; Vargas, Rafael

2005-01-01

Electrospray ionization of polyesters composed of isophthalic acid and neopentyl glycol produces carboxylate anions in negative mode and mainly sodium ion adducts in positive mode. A tandem mass spectrometry (MS/MS) study of these ions in a quadrupole ion trap shows that the collisionally activated dissociation pathways of the anions are simpler than those of the corresponding cations. Charge-remote fragmentations predominate in both cases, but the spectra obtained in negative mode are devoid of the complicating cation exchange observed in positive mode. MS/MS of the Na(+) adducts gives rise to a greater number of fragments but not necessarily more structural information. In either positive or negative mode, polyester oligomers with different end groups fragment by similar mechanisms. The observed fragments are consistent with rearrangements initiated by the end groups. Single-stage ESI mass spectra also are more complex in positive mode because of extensive H/Na substitutions; this is also true for matrix-assisted laser desorption ionization (MALDI) mass spectra. Hence, formation and analysis of anions might be the method of choice for determining block length, end group structure and copolymer sequence, provided the polyester contains at least one carboxylic acid end group that is ionizable to anions.

Wavelet-based peak detection and a new charge inference procedure for MS/MS implemented in ProteoWizard's msConvert.

PubMed

French, William R; Zimmerman, Lisa J; Schilling, Birgit; Gibson, Bradford W; Miller, Christine A; Townsend, R Reid; Sherrod, Stacy D; Goodwin, Cody R; McLean, John A; Tabb, David L

2015-02-06

We report the implementation of high-quality signal processing algorithms into ProteoWizard, an efficient, open-source software package designed for analyzing proteomics tandem mass spectrometry data. Specifically, a new wavelet-based peak-picker (CantWaiT) and a precursor charge determination algorithm (Turbocharger) have been implemented. These additions into ProteoWizard provide universal tools that are independent of vendor platform for tandem mass spectrometry analyses and have particular utility for intralaboratory studies requiring the advantages of different platforms convergent on a particular workflow or for interlaboratory investigations spanning multiple platforms. We compared results from these tools to those obtained using vendor and commercial software, finding that in all cases our algorithms resulted in a comparable number of identified peptides for simple and complex samples measured on Waters, Agilent, and AB SCIEX quadrupole time-of-flight and Thermo Q-Exactive mass spectrometers. The mass accuracy of matched precursor ions also compared favorably with vendor and commercial tools. Additionally, typical analysis runtimes (∼1-100 ms per MS/MS spectrum) were short enough to enable the practical use of these high-quality signal processing tools for large clinical and research data sets.

Petroleomics by Direct Analysis in Real Time-Mass Spectrometry.

PubMed

Romão, Wanderson; Tose, Lilian V; Vaz, Boniek G; Sama, Sara G; Lobinski, Ryszard; Giusti, Pierre; Carrier, Hervé; Bouyssiere, Brice

2016-01-01

The analysis of crude oil and its fractions by applying ambient ionization techniques remains underexplored in mass spectrometry (MS). Direct analysis in real time (DART) in the positive-ion mode was coupled to a linear quadrupole ion trap Orbitrap mass spectrometer (LTQ Orbitrap) to analyze crude oil, paraffin samples, and porphyrin standard compounds. The ionization parameters of DART-MS were optimized for crude oil analysis. DART-MS rendered the optimum conditions of the operation using paper as the substrate, T = 400°C, helium as the carrier gas, and a sample concentration ≥6 mg mL(-1). In the crude oils analysis, the DART(+)-Orbitrap mass spectra detected the typical N, NO, and O-containing compounds. In the paraffin samples, oxidized hydrocarbon species (Ox classes, where x = 1-4) with double-bond equivalent of 1-4 were detected, and their structures and connectivity were confirmed by collision-induced dissociation (CID) experiments. DART(+)-MS has identified the porphyrin standard compounds as [M + H](+) ions of m/z 615.2502 and 680.1763, where M = C44H30N4 and C44H28N4OV, respectively, based on the formula assignment and by phenyl losses observed on CID experiments.

The identification and analytical characterization of 2,2'-difluorofentanyl.

PubMed

Liu, Cuimei; Li, Tao; Han, Yu; Hua, Zhendong; Jia, Wei; Qian, Zhenhua

2018-04-01

New psychoactive substances (NPS) have expanded their distribution and become widely available in the global market in recent years. The illicit use of fentanyl and its analogs has become an important worldwide concern linked to their high potency and risk of fatal overdose. This study describes the analytical characterization of a new fentanyl derivative N-(1-(2-fluorophenethyl)-4-piperidinyl)-N-(2-fluorophenyl)propionamide (2,2'-difluorofentanyl). Identification was based on ultra-high-performance liquid chromatography-quadrupole time-of-flight-mass spectrometry (UHPLC-QTOF-MS), gas chromatography-mass spectrometry (GC-MS), Fourier transform infrared (FTIR) spectroscopy, and nuclear magnetic resonance (NMR) spectroscopy. To our knowledge, this study is the first to report on analytical data for this compound. The most abundant fragment ion in the electrospray ionization (ESI) mass spectrum under collision-induced dissociation (CID) mode was formed by the cleavage between the piperidine ring and the N-phenyl-amide moiety of the protonated molecule. Two diagnostic ions in the electron ionization (EI) mass spectrum were formed by the loss of a tropylium ion (M-91), and by the degradation of the piperidine ring and dissociate of the COC 2 H 5 moiety altogether, respectively. Copyright © 2017 John Wiley & Sons, Ltd.

Current role of liquid chromatography-mass spectrometry in clinical and forensic toxicology.

PubMed

Maurer, Hans H

2007-08-01

This paper reviews multi-analyte single-stage and tandem liquid chromatography-mass spectrometry (LC-MS) procedures using different mass analyzers (quadrupole, ion trap, time-of-flight) for screening, identification, and/or quantification of drugs, poisons, and/or their metabolites in blood, plasma, serum, or urine published after 2004. Basic information about the biosample assayed, work-up, LC column, mobile phase, ionization type, mass spectral detection mode, and validation data of each procedure is summarized in tables. The following analytes are covered: drugs of abuse, analgesics, opioids, sedative-hypnotics, benzodiazepines, antidepressants including selective-serotonin reuptake inhibitors (SSRIs), herbal phenalkylamines (ephedrines), oral antidiabetics, antiarrhythmics and other cardiovascular drugs, antiretroviral drugs, toxic alkaloids, quaternary ammonium drugs and herbicides, and dialkylphosphate pesticides. The pros and cons of the reviewed procedures are critically discussed, particularly, the need for studies on matrix effects, selectivity, analyte stability, and the use of stable-isotope labeled internal standards instead of unlabeled therapeutic drugs. In conclusion, LC-MS will probably become a gold standard for detection of very low concentrations particularly in alternative matrices and for quantification in clinical and forensic toxicology. However, some drawbacks still need to be addressed and finally overcome.

Determination of prohibited, small peptides in urine for sports drug testing by means of nano-liquid chromatography/benchtop quadrupole orbitrap tandem-mass spectrometry.

PubMed

Thomas, Andreas; Walpurgis, Katja; Krug, Oliver; Schänzer, Wilhelm; Thevis, Mario

2012-10-12

In the present study, a screening assay was developed comprising 11 prohibited peptides (<1.5 kDa) that are sufficiently purified from urine using weak cation exchange with subsequent determination of all substances by means of nanoUHPLC separation coupled to high resolution tandem mass spectrometry. These peptides included Gonadorelin (LH-RH), Desmopressin and 9 growth hormone releasing peptides (GHRP-1, -2, -4, -5, -6, Hexarelin, Alexamorelin, Ipamorelin and a GHRP-2 metabolite); however, the procedure is expandable to further target analytes or metabolites. The method was validated with a main focus on qualitative result interpretation considering the parameters specificity, linearity (0-500 pg/mL), recovery (45-95%), precision (<20% at 100 pg/mL), limits of detection (2-10 pg/mL), robustnesss and ion suppression. The proof-of-principle was shown by analysing excretion study urine samples for LHRH, Desmopressin and GHRP-2. Copyright © 2012 Elsevier B.V. All rights reserved.

Correlation between species-specific metabolite profiles and bioactivities of blueberries (Vaccinium spp.).

PubMed

Lee, Sarah; Jung, Eun Sung; Do, Seon-Gil; Jung, Ga-Young; Song, Gwanpil; Song, Jung-Min; Lee, Choong Hwan

2014-03-05

Metabolite profiling of three blueberry species (Vaccinium bracteatum Thunb., V. oldhamii Miquel., and V. corymbosum L.) was performed using gas chromatography-time-of-flight-mass spectrometry (GC-TOF-MS) and ultraperformance liquid chromatography-quadrupole-time-of-flight-mass spectrometry (UPLC-Q-TOF-MS) combined multivariate analysis. Partial least-squares discriminant analysis clearly showed metabolic differences among species. GC-TOF-MS analysis revealed significant differences in amino acids, organic acids, fatty acids, sugars, and phenolic acids among the three blueberry species. UPLC-Q-TOF-MS analysis indicated that anthocyanins were the major metabolites distinguishing V. bracteatum from V. oldhamii. The contents of anthocyanins such as glycosides of cyanidin were high in V. bracteatum, while glycosides of delphinidin, petunidin, and malvidin were high in V. oldhamii. Antioxidant activities assessed using ABTS and DPPH assays showed the greatest activity in V. oldhamii and revealed the highest correlation with total phenolic, total flavonoid, and total anthocyanin contents and their metabolites.

Identification and quantification of cannabinoids in Cannabis sativa L. plants by high performance liquid chromatography-mass spectrometry.

PubMed

Aizpurua-Olaizola, Oier; Omar, Jone; Navarro, Patricia; Olivares, Maitane; Etxebarria, Nestor; Usobiaga, Aresatz

2014-11-01

High performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) has been successfully applied to cannabis plant extracts in order to identify cannabinoid compounds after their quantitative isolation by means of supercritical fluid extraction (SFE). MS conditions were optimized by means of a central composite design (CCD) approach, and the analysis method was fully validated. Six major cannabinoids [tetrahydrocannabinolic acid (THCA), tetrahydrocannabinol (THC), cannabidiol (CBD), tetrahydrocannabivarin (THCV), cannabigerol (CBG), and cannabinol (CBN)] were quantified (RSD < 10%), and seven more cannabinoids were identified and verified by means of a liquid chromatograph coupled to a quadrupole-time-of-flight (Q-ToF) detector. Finally, based on the distribution of the analyzed cannabinoids in 30 Cannabis sativa L. plant varieties and the principal component analysis (PCA) of the resulting data, a clear difference was observed between outdoor and indoor grown plants, which was attributed to a higher concentration of THC, CBN, and CBD in outdoor grown plants.

Risk assessment derived from migrants identified in several adhesives commonly used in food contact materials.

PubMed

Canellas, E; Vera, P; Nerín, C

2015-01-01

Adhesives are used to manufacture multilayer materials, where their components pass through the layers and migrate to the food. Nine different adhesives (acrylic, vinyl and hotmelt) and their migration in 21 laminates for future use as market samples have been evaluated and risk assessment has been carried out. A total of 75 volatiles and non volatile compounds were identified by gas chromatography-mass spectrometry and ultra-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry. Most of the compounds migrated below their specific migration limit (SML), lowest observed adverse effect level (LOAEL), no observed adverse effect level (NOAEL) and values recommended by Cramer. Six compounds classified as high toxicity class III according to Cramer classification, migrated over their SML and exposure values recommended by Cramer, when they were applied in the full area of the packaging. Nevertheless, these adhesives fulfill the threshold in the real application as they are applied in a small area of the packaging. Copyright © 2014 Elsevier Ltd. All rights reserved.

Qualitative and quantitative analysis of branches in dextran using high-performance anion exchange chromatography coupled to quadrupole time-of-flight mass spectrometry.

PubMed

Yi, Lin; Ouyang, Yilan; Sun, Xue; Xu, Naiyu; Linhardt, Robert J; Zhang, Zhenqing

2015-12-04

Dextran, a family of natural polysaccharides, consists of an α (1→6) linked-glucose main (backbone) chain having a number of branches. The determination of the types and the quantities of branches in dextran is important in understanding its various biological roles. In this study, a hyphenated method using high-performance anion exchange chromatography (HPAEC) in parallel with pulsed amperometric detection (PAD) and mass spectrometry (MS) was applied to qualitative and quantitative analysis of dextran branches. A rotary cation-exchange cartridge array desalter was used for removal of salt from the HPAEC eluent making it MS compatible. MS and MS/MS were used to provide structural information on the enzymatically prepared dextran oligosaccharides. PAD provides quantitative data on the ratio of enzyme-resistant, branched dextran oligosaccharides. Both the types and degree of branching found in a variety of dextrans could be simultaneously determined online using this method. Copyright © 2015 Elsevier B.V. All rights reserved.

Analysis of amadori-glycated phosphatidylethanolamine in the plasma of healthy subjects and diabetic patients by liquid chromatography-tandem mass spectrometry.

PubMed

Miyazawa, Teruo; Ibusuki, Daigo; Yamashita, Shinji; Nakagawa, Kiyotaka

2008-04-01

Peroxidized phospholipid-mediated cytotoxity, the abnormal increase in the levels of phosphatidylcholine hydroperoxide (PCOOH) found in the plasma of type 2 diabetic patients, is involved in the pathophysiology of many diseases. PCOOH accumulation may be related to Amadori-glycated phosphatidylethanolamine (deoxy-D-fructosyl PE, or Amadori-PE) because Amadori-PE causes oxidative stress. However, the occurrence of lipid glycation products, including Amadori-PE, in vivo remains unclear. We developed a method to analyze Amadori-PE by using quadrupole/linear ion-trap mass spectrometry, the Applied Biosystems 4000 Q TRAP. We found that pyridoxals could easily be condensed with PE before the glucose-PE reaction occurred. The PE-pyridoxal 5'-phosphate adduct was detectable in human red blood cells, and the increased plasma Amadori-PE concentration in streptozotocin-induced diabetic rats was decreased by dietary supplementation with pyridoxal 5'-phosphate. Therefore, it is likely that pyridoxal 5'-phosphate acts as a lipid glycation inhibitor in vivo, and this may contribute to diabetes prevention.

High-throughput and sensitive analysis of 3-monochloropropane-1,2-diol fatty acid esters in edible oils by supercritical fluid chromatography/tandem mass spectrometry.

PubMed

Hori, Katsuhito; Matsubara, Atsuki; Uchikata, Takato; Tsumura, Kazunobu; Fukusaki, Eiichiro; Bamba, Takeshi

2012-08-10

We have established a high-throughput and sensitive analytical method based on supercritical fluid chromatography (SFC) coupled with triple quadrupole mass spectrometry (QqQ MS) for 3-monochloropropane-1,2-diol (3-MCPD) fatty acid esters in edible oils. All analytes were successfully separated within 9 min without sample purification. The system was precise and sensitive, with a limit of detection less than 0.063 mg/kg. The recovery rate of 3-MCPD fatty acid esters spiked into oil samples was in the range of 62.68-115.23%. Furthermore, several edible oils were tested for analyzing 3-MCPD fatty acid ester profiles. This is the first report on the analysis of 3-MCPD fatty acid esters by SFC/QqQ MS. The developed method will be a powerful tool for investigating 3-MCPD fatty acid esters in edible oils. Copyright © 2012 Elsevier B.V. All rights reserved.

Determination of lansoprazole in human plasma by rapid resolution liquid chromatography-electrospray tandem mass spectrometry: application to a bioequivalence study on Chinese volunteers.

PubMed

Wu, Guo-Lan; Zhou, Hui-Li; Shentu, Jian-Zhong; He, Qiao-Jun; Yang, Bo

2008-12-15

A simple, sensitive and rapid LC/MS/MS method was developed for the quantification of lansoprazole in human plasma. After a simple sample preparation procedure by one-step protein precipitation with acetonitrile, lansoprazole and the internal standard bicalutamide were chromatographed on a Zorbax SB-C(18) (3.0 mm x 150 mm, 3.5 microm, Agilent) column with the mobile phase consisted of methanol-water (70:30, v/v, containing 5 mM ammonium formate, pH was adjusted to 7.85 by 1% ammonia solution). Detection was performed on a triple quadrupole tandem mass spectrometry by multiple reaction monitoring (MRM) mode via negative eletrospray ionization source (ESI(-)). The lower limit of quantification was 5.5 ng/mL, and the assay exhibited a linear range of 5.5-2200.0 ng/mL. The validated method was successfully applied to investigate the bioequivalence between two kinds of preparation (test vs. reference product) in twenty-eight healthy male Chinese volunteers.

Isotopologue Distributions of Peptide Product Ions by Tandem Mass Spectrometry: Quantitation of Low Levels of Deuterium Incorporation1

PubMed Central

Wang, Benlian; Sun, Gang; Anderson, David R.; Jia, Minghong; Previs, Stephen; Anderson, Vernon E.

2007-01-01

Protonated molecular peptide ions and their product ions generated by tandem mass spectrometry appear as isotopologue clusters due to the natural isotopic variations of carbon, hydrogen, nitrogen, oxygen and sulfur. Quantitation of the isotopic composition of peptides can be employed in experiments involving isotope effects, isotope exchange, isotopic labeling by chemical reactions, and studies of metabolism by stable isotope incorporation. Both ion trap and quadrupole-time of flight mass spectrometry are shown to be capable of determining the isotopic composition of peptide product ions obtained by tandem mass spectrometry with both precision and accuracy. Tandem mass spectra obtained in profile-mode of clusters of isotopologue ions are fit by non-linear least squares to a series of Gaussian peaks (described in the accompanying manuscript) which quantify the Mn/M0 values which define the isotopologue distribution (ID). To determine the isotopic composition of product ions from their ID, a new algorithm that predicts the Mn/M0 ratios is developed which obviates the need to determine the intensity of all of the ions of an ID. Consequently a precise and accurate determination of the isotopic composition a product ion may be obtained from only the initial values of the ID, however the entire isotopologue cluster must be isolated prior to fragmentation. Following optimization of the molecular ion isolation width, fragmentation energy and detector sensitivity, the presence of isotopic excess (2H, 13C, 15N, 18O) is readily determined within 1%. The ability to determine the isotopic composition of sequential product ions permits the isotopic composition of individual amino acid residues in the precursor ion to be determined. PMID:17559791

Direct atmospheric pressure chemical ionisation ion trap mass spectrometry for aroma analysis: Speed, sensitivity and resolution of isobaric compounds

NASA Astrophysics Data System (ADS)

Jublot, Lionel; Linforth, Robert S. T.; Taylor, Andrew J.

2005-06-01

Atmospheric pressure chemical ionisation (APCI) sources were developed for real time analysis of volatile release from foods using an ion trap (IT) mass spectrometer (MS). Key objectives were spectral simplicity (minimal fragmentation), response time and signal to noise ratio. The benefits of APCI-IT-MS were assessed by comparing the performance for in vivo and headspace analyses with that obtained using APCI coupled to a quadrupole mass analyser. Using MS-MS, direct APCI-IT-MS was able to differentiate mixtures of some C6 and terpene isobaric aroma compounds. Resolution could be achieved for some compounds by monitoring specific secondary ions. Direct resolution was also achieved with two of the three isobaric compounds released from chocolate with time as the sample was eaten.

Pentaerythritol Tetranitrate (PETN) Surveillance by HPLC-MS: Instrumental Parameters Development

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harvey, C A; Meissner, R

Surveillance of PETN Homologs in the stockpile here at LLNL is currently carried out by high performance liquid chromatography (HPLC) with ultra violet (UV) detection. Identification of unknown chromatographic peaks with this detection scheme is severely limited. The design agency is aware of the limitations of this methodology and ordered this study to develop instrumental parameters for the use of a currently owned mass spectrometer (MS) as the detection system. The resulting procedure would be a ''drop-in'' replacement for the current surveillance method (ERD04-524). The addition of quadrupole mass spectrometry provides qualitative identification of PETN and its homologs (Petrin, DiPEHN,more » TriPEON, and TetraPEDN) using a LLNL generated database, while providing mass clues to the identity of unknown chromatographic peaks.« less

High energy collisions on tandem time-of-flight mass spectrometers†

PubMed Central

Cotter, Robert J.

2013-01-01

Long before the introduction of matrix-assisted laser desorption (MALDI), electrospray ionization (ESI), Orbitraps and any of the other tools that are now used ubiquitously for proteomics and metabolomics, the highest performance mass spectrometers were sector instruments, providing high resolution mass measurements by combining an electrostatic energy analyzer (E) with a high field magnet (B). In its heyday, the four sector mass spectrometer (or EBEB) was the crown jewel, providing the highest performance tandem mass spectrometry using single, high energy collisions to induce fragmentation. During a time in which quadrupole and tandem triple quadrupole instruments were also enjoying increased usage and popularity, there were nonetheless some clear advantages for sectors over their low collision energy counterparts. Time-of-flight mass spectrometers are high voltage, high vacuum instruments that have much in common with sectors and have inspired the development of tandem instruments exploiting single high energy collisions. In this retrospective we recount our own journey to produce high performance time-of-flights and tandems, describing the basic theory, problems and the advantages for such instruments. An experiment testing impulse collision theory (ICT) underscores the similarities with sector mass spectrometers where this concept was first developed. Applications provide examples of more extensive fragmentation, side chain cleavages and charge-remote fragmentation, also characteristic of high energy sector mass spectrometers. Moreover, the so-called curved-field reflectron has enabled the design of instruments that are simpler, collect and focus all of the ions, and may provide the future technology for the clinic, for tissue imaging and the characterization of microorganisms. PMID:23519928

Use of ICP/MS with ultrasonic nebulizer for routine determination of uranium activity ratios in natural water

USGS Publications Warehouse

Kraemer, T.F.; Doughten, M.W.; Bullen, T.D.

2002-01-01

A method is described that allows precise determination of 234U/238U activity ratios (UAR) in most natural waters using commonly available inductively coupled plasma/mass spectrometry (ICP/MS) instrumentation and accessories. The precision achieved by this technique (??0.5% RSD, 1 sigma) is intermediate between thermal ionization mass spectrometry (??0.25% RSID, 1 sigma) and alpha particle spectrometry (??5% RSD, 1 sigma). It is precise and rapid enough to allow analysis of a large number of samples in a short period of time at low cost using standard, commercially available quadrupole instrumentation with ultrasonic nebulizer and desolvator accessories. UARs have been analyzed successfully in fresh to moderately saline waters with U concentrations of from less than 1 ??g/L to nearly 100 ??g/L. An example of the uses of these data is shown for a study of surface-water mixing in the North Platte River in western Nebraska. This rapid and easy technique should encourage the wider use of uranium isotopes in surface-water and groundwater investigations, both for qualitative (e.g. identifying sources of water) and quantitative (e.g. determining end-member mixing ratios purposes.

Orthogonal Injection Ion Funnel Interface Providing Enhanced Performance for Selected Reaction Monitoring-Triple Quadrupole Mass Spectrometry

DOE PAGES

Chen, Tsung-Chi; Fillmore, Thomas L.; Prost, Spencer A.; ...

2015-06-24

The electrodynamic ion funnel facilitates efficient focusing and transfer of charged particles in the higher pressure regions (e.g. ion source interfaces) of mass spectrometers, and thus providing increased sensitivity. An “off-axis” ion funnel design has been developed to reduce the source contamination and interferences from, e.g. ESI droplet residue and other poorly focused neutral or charged particles with very high mass-to charge ratios. In this study a dual ion funnel interface consisting of an orthogonal higher pressure electrodynamic ion funnel (HPIF) and an ion funnel trap combined with a triple quadruple mass spectrometer was developed and characterized. An orthogonal ionmore » injection inlet and a repeller plate electrode was used to direct ions to an ion funnel HPIF at 9-10 Torr pressure. Several critical factors for the HPIF were characterized, including the effects of RF amplitude, DC gradient and operating pressure. Compared to the triple quadrupole standard interface more than 4-fold improvement in the limit of detection for the direct quantitative MS analysis of low abundance peptides was observed. Lastly, the sensitivity enhancement in liquid chromatography selected reaction monitoring (SRM) analyses of low abundance peptides spiked into a highly complex mixture was also compared with that obtained using a both commercial s-lens interface and a in-line dual ion funnel interface.« less

Wide-Scope Screening Method for Multiclass Veterinary Drug Residues in Fish, Shrimp, and Eel Using Liquid Chromatography-Quadrupole High-Resolution Mass Spectrometry.

PubMed

Turnipseed, Sherri B; Storey, Joseph M; Lohne, Jack J; Andersen, Wendy C; Burger, Robert; Johnson, Aaron S; Madson, Mark R

2017-08-30

A screening method for veterinary drug residues in fish, shrimp, and eel using LC with a high-resolution MS instrument has been developed and validated. The method was optimized for over 70 test compounds representing a variety of veterinary drug classes. Tissues were extracted by vortex mixing with acetonitrile acidified with 2% acetic acid and 0.2% p-toluenesulfonic acid. A centrifuged portion of the extract was passed through a novel solid phase extraction cartridge designed to remove interfering matrix components from tissue extracts. The eluent was then evaporated and reconstituted for analysis. Data were collected with a quadrupole-Orbitrap high-resolution mass spectrometer using both nontargeted and targeted acquisition methods. Residues were detected on the basis of the exact mass of the precursor and a product ion along with isotope pattern and retention time matching. Semiquantitative data analysis compared MS 1 signal to a one-point extracted matrix standard at a target testing level. The test compounds were detected and identified in salmon, tilapia, catfish, shrimp, and eel extracts fortified at the target testing levels. Fish dosed with selected analytes and aquaculture samples previously found to contain residues were also analyzed. The screening method can be expanded to monitor for an additional >260 veterinary drugs on the basis of exact mass measurements and retention times.

Quantitation of tacrolimus in whole blood using high performance liquid chromatography-tandem mass spectrometry (HPLC-MS-MS).

PubMed

Donaldson, Keri J; Shaw, Leslie M

2010-01-01

We describe a multiple reaction monitoring positive ion HPLC/tandem mass spectrometric method for quantification of tacrolimus in human whole blood with online extraction and cleanup. Included in this procedure: API 2000 triple quadrupole mass spectrometer with turbo-ion spray source (Applied Biosystems, Foster City, CA); 10-port diverter/switching valve (Valco, Houston, TX); HPLC system (Agilent Technologies series 1100, Wilmington, DE); 10 mm (C(18)) guard cartridge (Perkin Elmer, Norwalk, CT) used as an extraction column; a Nova-Pak C18 analytical column (2.1 x 150 mm I.D., 4 microm, Waters Corp, Milford, MA); washing solution, methanol: 30 mM ammonium acetate pH 5.1 (80:20); eluting solution, methanol:30 mM ammonium acetate pH 5.1 (97:3); flow rate 0.8 mL/min; and a run-time of 2.8 min. The first and third quadrupoles were set to detect the ammonium adduct ion and a high mass fragment of tacrolimus (m/z 821.5-->768.3), and of an internal standard (ascomycin) (m/z 901.8-->834.4). The lower limit of quantification of this method is 3.75 mg/L. The concentration of drug is determined by comparing peak-area ratios for tacrolimus and internal standard to a standard curve constructed using non-weighted linear through zero regression.

High-performance multiple-reflection time-of-flight mass spectrometers for research with exotic nuclei and for analytical mass spectrometry

NASA Astrophysics Data System (ADS)

Plaß, Wolfgang R.; Dickel, Timo; Ayet San Andres, Samuel; Ebert, Jens; Greiner, Florian; Hornung, Christine; Jesch, Christian; Lang, Johannes; Lippert, Wayne; Majoros, Tamas; Short, Devin; Geissel, Hans; Haettner, Emma; Reiter, Moritz P.; Rink, Ann-Kathrin; Scheidenberger, Christoph; Yavor, Mikhail I.

2015-11-01

A class of multiple-reflection time-of-flight mass spectrometers (MR-TOF-MSs) has been developed for research with exotic nuclei at present and future accelerator facilities such as GSI and FAIR (Darmstadt), and TRIUMF (Vancouver). They can perform highly accurate mass measurements of exotic nuclei, serve as high-resolution, high-capacity mass separators and be employed as diagnostics devices to monitor the production, separation and manipulation of beams of exotic nuclei. In addition, a mobile high-resolution MR-TOF-MS has been developed for in situ applications in analytical mass spectrometry ranging from environmental research to medicine. Recently, the MR-TOF-MS for GSI and FAIR has been further developed. A novel RF quadrupole-based ion beam switchyard has been developed that allows merging and splitting of ion beams as well as transport of ions into different directions. It efficiently connects a test and reference ion source and an auxiliary detector to the system. Due to an increase in the kinetic energy of the ions in the time-of-flight analyzer of the MR-TOF-MS, a given mass resolving power is now achieved in less than half the time-of-flight. Conversely, depending on the time-of-flight, the mass resolving power has been increased by a factor of more than two.

Design and fabrication of a basic mass analyzer and vacuum system

NASA Technical Reports Server (NTRS)

Judson, C. M.; Josias, C.; Lawrence, J. L., Jr.

1977-01-01

A two-inch hyperbolic rod quadrupole mass analyzer with a mass range of 400 to 200 amu and a sensitivity exceeding 100 packs per billion has been developed and tested. This analyzer is the basic hardware portion of a microprocessor-controlled quadrupole mass spectrometer for a Gas Analysis and Detection System (GADS). The development and testing of the hyperbolic-rod quadrupole mass spectrometer and associated hardware are described in detail.

Identification of V-type nerve agents in vapor samples using a field-portable capillary gas chromatography/membrane-interfaced electron ionization quadrupole mass spectrometry instrument with Tri-Bed concentrator and fluoridating conversion tube.

PubMed

Ohrui, Y; Nagoya, T; Kurimata, N; Sodeyama, M; Seto, Y

2017-07-01

A field-portable gas chromatography-mass spectrometry (GC-MS) system (Hapsite ER) was evaluated for the detection of nonvolatile V-type nerve agents (VX and Russian VX (RVX)) in the vapor phase. The Hapsite ER system consists of a Tri-Bed concentrator gas sampler, a nonpolar low thermal-mass capillary GC column and a hydrophobic membrane-interfaced electron ionization quadrupole mass spectrometer evacuated by a non-evaporative getter pump. The GC-MS system was attached to a VX-G fluoridating conversion tube containing silver nitrate and potassium fluoride. Sample vapors of VX and RVX were converted into O-ethyl methylphosphonofluoridate (EtGB) and O-isobutyl methylphosphonofluoridate (iBuGB), respectively. These fluoridated derivatives were detected within 10 min. No compounds were detected when the VX and RVX samples were analyzed without the conversion tube. A vapor sample of tabun (GA) was analyzed, in which GA and O-ethyl N,N-dimethylphosphoramidofluoridate were detected. The molar recovery percentages of EtGB and iBuGB from VX and RVX vapors varied from 0.3 to 17%, which was attributed to variations in the vaporization efficiency of the glass vapor container. The conversion efficiencies of the VX-G conversion tube for VX and RVX to their phosphonate derivatives were estimated to be 40%. VX and RVX vapors were detected at concentrations as low as 0.3 mg m -3 . Gasoline vapor was found to interfere with the analyses of VX and RVX. In the presence of 160 mg m -3 gasoline, the detection limits of VX and RVX vapor were increased to 20 mg m -3 . Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Matrix-assisted laser desorption/ionization coupled with quadrupole/orthogonal acceleration time-of-flight mass spectrometry for protein discovery, identification, and structural analysis.

PubMed

Baldwin, M A; Medzihradszky, K F; Lock, C M; Fisher, B; Settineri, T A; Burlingame, A L

2001-04-15

The design and operation of a novel UV-MALDI ionization source on a commercial QqoaTOF mass spectrometer (Applied Biosystem/MDS Sciex QSTAR Pulsar) is described. Samples are loaded on a 96-well target plate, the movement of which is under software control and can be readily automated. Unlike conventional high-energy MALDI-TOF, the ions are produced with low energies (5-10 eV) in a region of relatively low vacuum (8 mTorr). Thus, they are cooled by extensive low-energy collisions before selection in the quadrupole mass analyzer (Q1), potentially giving a quasi-continuous ion beam ideally suited to the oaTOF used for mass analysis of the fragment ions, although ion yields from individual laser shots may vary widely. Ion dissociation is induced by collisions with argon in an rf-only quadrupole cell, giving typical low-energy CID spectra for protonated peptide ions. Ions separated in the oaTOF are registered by a four-anode detector and time-to-digital converter and accumulated in "bins" that are 625 ps wide. Peak shapes depend upon the number of ion counts in adjacent bins. As expected, the accuracy of mass measurement is shown to be dependent upon the number of ions recorded for a particular peak. With internal calibration, mass accuracy better than 10 ppm is attainable for peaks that contain sufficient ions to give well-defined Gaussian profiles. By virtue of its high resolution, capability for accurate mass measurements, and sensitivity in the low-femotomole range, this instrument is ideally suited to protein identification for proteomic applications by generation of peptide tags, manual sequence interpretation, identification of modifications such as phosphorylation, and protein structural elucidation. Unlike the multiply charged ions typical of electrospray ionization, the singly charged MALDI-generated peptide ions show a linear dependence of optimal collision energy upon molecular mass, which is advantageous for automated operation. It is shown that the novel pulsing technique of this instrument that increases the sensitivity for precursor ions scans is applicable to the identification of peptides labeled with isotope-coded affinity tags.