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Sample records for em aquidauana ms

  1. The E-MS Algorithm: Model Selection with Incomplete Data.

    PubMed

    Jiang, Jiming; Nguyen, Thuan; Rao, J Sunil

    2015-04-04

    We propose a procedure associated with the idea of the E-M algorithm for model selection in the presence of missing data. The idea extends the concept of parameters to include both the model and the parameters under the model, and thus allows the model to be part of the E-M iterations. We develop the procedure, known as the E-MS algorithm, under the assumption that the class of candidate models is finite. Some special cases of the procedure are considered, including E-MS with the generalized information criteria (GIC), and E-MS with the adaptive fence (AF; Jiang et al. 2008). We prove numerical convergence of the E-MS algorithm as well as consistency in model selection of the limiting model of the E-MS convergence, for E-MS with GIC and E-MS with AF. We study the impact on model selection of different missing data mechanisms. Furthermore, we carry out extensive simulation studies on the finite-sample performance of the E-MS with comparisons to other procedures. The methodology is also illustrated on a real data analysis involving QTL mapping for an agricultural study on barley grains.

  2. The E-MS Algorithm: Model Selection with Incomplete Data

    PubMed Central

    Jiang, Jiming; Nguyen, Thuan; Rao, J. Sunil

    2014-01-01

    We propose a procedure associated with the idea of the E-M algorithm for model selection in the presence of missing data. The idea extends the concept of parameters to include both the model and the parameters under the model, and thus allows the model to be part of the E-M iterations. We develop the procedure, known as the E-MS algorithm, under the assumption that the class of candidate models is finite. Some special cases of the procedure are considered, including E-MS with the generalized information criteria (GIC), and E-MS with the adaptive fence (AF; Jiang et al. 2008). We prove numerical convergence of the E-MS algorithm as well as consistency in model selection of the limiting model of the E-MS convergence, for E-MS with GIC and E-MS with AF. We study the impact on model selection of different missing data mechanisms. Furthermore, we carry out extensive simulation studies on the finite-sample performance of the E-MS with comparisons to other procedures. The methodology is also illustrated on a real data analysis involving QTL mapping for an agricultural study on barley grains. PMID:26783375

  3. SAND FLIES (DIPTERA: PSYCHODIDAE) IN AN ENDEMIC AREA OF LEISHMANIASIS IN AQUIDAUANA MUNICIPALITY, PANTANAL OF MATO GROSSO DO SUL , BRAZIL.

    PubMed

    Figueiredo, Helen Rezende de; Santos, Mirella Ferreira da Cunha; Casaril, Aline Etelvina; Infran, Jucelei Oliveira de Moura; Ribeiro, Leticia Moraes; Fernandes, Carlos Eurico Dos Santos; Oliveira, Alessandra Gutierrez de

    2016-12-08

    The Aquidauana municipality is considered an endemic area of leishmaniasis and an important tourist site in Mato Grosso do Sul State. The aim of this study was to investigate the sand fly fauna in the city of Aquidauana. Captures were carried out twice a month, from April 2012 to March 2014 with automatic light traps and active aspiration, in the peridomicile and domicile of six residences. A total of 9,338 specimens were collected, 3,179 and 6,159 using light traps and active aspiration, respectively. The fauna consisted of: Brumptomyia brumpti, Evandromyia aldafalcaoae, Ev. evandroi, Ev. lenti, Ev. orcyi, Ev. sallesi, Ev. termitophila, Ev. walkeri, Lutzomyia longipalpis and Psathyromyia bigeniculata. The most abundant species captured was Lutzomyia longipalpis, present in all the ecotopes, predominantly in peridomicile areas, and mainly males. Leishmania DNA was not detected in the insects. It was observed the abundance of the sand fly fauna in the region, as well as the high frequency of Lu. longipalpis, the main vector of L. infantum. The results of this study show the need to increase the monitoring and more effective control measures. It is noteworthy that the studied region presents several activities related to tourism and recreation, increasing the risk of transmission of leishmaniasis to this particular human population.

  4. Biostratigraphy and paleoecology of an unusual palynological record from the Aquidauana Formation, Late Pennsylvanian of Paraná Basin.

    PubMed

    Souza, Paulo A; Perinotto, José A J; Félix, Cristina M; Araújo, Bruno C

    2015-01-01

    The Aquidauana Formation is a Permo-Carboniferous sedimentary unit, widely stratigraphicaly distributed in the northwestern and northern portions of the Paraná Basin. However, little paleontological data is available from this formation, preventing accurate biostratigraphic and paleoecological interpretations. An abundant, diversified and well preserved assemblage of palynomorphs was recognized from sampling conducted in an outcrop section in Cipolândia District of Aquidauana Municipality, state of Mato Grosso do Sul, Brazil. A total of 35 indigenous palynomorph taxa was recognized, comprising 6 species of spores (related to 5 genera), 28 species of pollen grains (14 genera) and 1 species of chlorophycean algae. Monosaccate pollen grains are exceptionally dominant, representing 90.38% of the association, particularly constituted by species of the genera Cannanoropollis (30.41% of the total assemblage), Potonieisporites (28.14%) and Plicatipollenites (19.52%). This quantitative overrepresentation is not usual from Gondwana deposits, revealing a particular plant dominance of Cordaitales in the terrestrial flora. These results are interpreted as an upland ecology characterized by plants with a moisture-independent reproduction strategy, under a glacial climate influence. Certain species of pollen allow assignment of this assemblage to the Crucisaccites monoletus Zone (Late Pennsylvanian), which had been recognized only in the middle portion of the Itararé Group at the northeastern margin of the basin.

  5. SAND FLIES (DIPTERA: PSYCHODIDAE) IN AN ENDEMIC AREA OF LEISHMANIASIS IN AQUIDAUANA MUNICIPALITY, PANTANAL OF MATO GROSSO DO SUL , BRAZIL

    PubMed Central

    de FIGUEIREDO, Helen Rezende; SANTOS, Mirella Ferreira da Cunha; CASARIL, Aline Etelvina; INFRAN, Jucelei Oliveira de Moura; RIBEIRO, Leticia Moraes; FERNANDES, Carlos Eurico dos Santos; de OLIVEIRA, Alessandra Gutierrez

    2016-01-01

    SUMMARY The Aquidauana municipality is considered an endemic area of leishmaniasis and an important tourist site in Mato Grosso do Sul State. The aim of this study was to investigate the sand fly fauna in the city of Aquidauana. Captures were carried out twice a month, from April 2012 to March 2014 with automatic light traps and active aspiration, in the peridomicile and domicile of six residences. A total of 9,338 specimens were collected, 3,179 and 6,159 using light traps and active aspiration, respectively. The fauna consisted of: Brumptomyia brumpti, Evandromyia aldafalcaoae, Ev. evandroi, Ev. lenti, Ev. orcyi, Ev. sallesi, Ev. termitophila, Ev. walkeri, Lutzomyia longipalpis and Psathyromyia bigeniculata. The most abundant species captured was Lutzomyia longipalpis, present in all the ecotopes, predominantly in peridomicile areas, and mainly males. Leishmania DNA was not detected in the insects. It was observed the abundance of the sand fly fauna in the region, as well as the high frequency of Lu. longipalpis, the main vector of L. infantum. The results of this study show the need to increase the monitoring and more effective control measures. It is noteworthy that the studied region presents several activities related to tourism and recreation, increasing the risk of transmission of leishmaniasis to this particular human population. PMID:27982353

  6. Natural infection of gastrointestinal nematodes in long-nosed armadillos Dasypus novemcinctus Linnaeus, 1758 from Pantanal wetlands, Aquidauana sub-region, Mato Grosso do Sul State, with the description of Hadrostrongylus speciosum n. gen. et n. sp. (Molineidae: Anoplostrongylinae).

    PubMed

    Lux Hoppe, Estevam G; do Nascimento, Adjair Antonio

    2007-03-15

    This study evaluated the gastrointestinal helminth fauna of long-nosed armadillos, Dasypus novemcinctus, from the Pantanal wetlands, Aquidauana sub-region, Aquidauana County, Mato Grosso do Sul State, Brazil. Thirteen species of nematodes, comprising seven genera and four families, were recovered from their gastrointestinal tracts. The following descriptors of infection were determined: prevalence, variation of intensity, average intensity and abundance. Hadrostrongylus speciosum n. gen. et n. sp. is first described here.

  7. The influence of effective microorganisms (EM) and yeast on the degradation of strobilurins and carboxamides in leafy vegetables monitored by LC-MS/MS and health risk assessment.

    PubMed

    Wołejko, Elżbieta; Łozowicka, Bożena; Kaczyński, Piotr; Jankowska, Magdalena; Piekut, Jolanta

    2016-01-01

    The aim of this study was to determine the behaviour of strobilurin and carbocyamides commonly used in chemical protection of lettuce depending on carefully selected effective microorganisms (EM) and yeast (Y). Additionally, the assessment of the chronic health risk during a 2-week experiment was performed. The statistical method for correlation of physico-chemical parameters and time of degradation for pesticides was applied. In this study, the concentration of azoxystrobin, boscalid, pyraclostrobin and iprodione using liquid chromatography-mass spectrometry (LC-MS/MS) in the matrix of lettuce plants was performed, and there was no case of concentration above maximum residues levels. Before harvest, four fungicides and their mixture with EM (1 % and 10 %) and/or yeast 5 % were applied. In our work, the mixtures of 1%EM + Y and 10%EM + Y both stimulated and inhibited the degradation of the tested active substances. Adding 10%EM to the test substances strongly inhibited the degradation of iprodione, and its concentration decreased by 30 %, and in the case of other test substances, the degradation was approximately 60 %. Moreover, the addition of yeast stimulated the distribution of pyraclostrobin and boscalid in lettuce leaves. The risk assessment for the pesticides ranged from 0.4 to 64.8 % on day 1, but after 14 days, it ranged from 0.0 to 20.9 % for children and adults, respectively. It indicated no risk of adverse effects following exposure to individual pesticides and their mixtures with EM and yeast.

  8. Pediatric MS

    MedlinePlus

    ... is diagnosed with MS. Learn More Learn More Network of Pediatric MS Centers The National MS Society ... MS Study Group (2004) and established a nationwide network of six Pediatric MS Centers of Excellence (2006) ...

  9. Pediatric MS

    MedlinePlus

    ... video) Watch Video Students with MS and the Academic Setting: A Handbook for School Personnel (.pdf) Download Brochure Managing School-Related Issues: A Guide for Parents with a Child or Teen Living with MS (.pdf) Download Brochure Network of Pediatric MS Centers Learn More Pediatric MS ...

  10. MS Detectors

    SciTech Connect

    Koppenaal, David W.; Barinaga, Charles J.; Denton, M Bonner B.; Sperline, Roger P.; Hieftje, Gary M.; Schilling, G. D.; Andrade, Francisco J.; Barnes IV., James H.

    2005-11-01

    Good eyesight is often taken for granted, a situation that everyone appreciates once vision begins to fade with age. New eyeglasses or contact lenses are traditional ways to improve vision, but recent new technology, i.e. LASIK laser eye surgery, provides a new and exciting means for marked vision restoration and improvement. In mass spectrometry, detectors are the 'eyes' of the MS instrument. These 'eyes' have also been taken for granted. New detectors and new technologies are likewise needed to correct, improve, and extend ion detection and hence, our 'chemical vision'. The purpose of this report is to review and assess current MS detector technology and to provide a glimpse towards future detector technologies. It is hoped that the report will also serve to motivate interest, prompt ideas, and inspire new visions for ion detection research.

  11. Multi-isotope tracers to investigate processes in the Elbe, Weser and Ems river catchment using B, Mo, Sr, and Pb isotope ratios assessed by MC ICP-MS

    NASA Astrophysics Data System (ADS)

    Irrgeher, Johanna; Reese, Anna; Zimmermann, Tristan; Prohaska, Thomas; Retzmann, Anika; Wieser, Michael E.; Zitek, Andreas; Proefrock, Daniel

    2017-04-01

    Environmental monitoring of complex ecosystems requires reliable sensitive techniques based on sound analytical strategies to identify the source, fate and sink of elements and matter. Isotopic signatures can serve to trace pathways by making use of specific isotopic fingermarks or to distinguish between natural and anthropogenic sources. The presented work shows the potential of using the isotopic variation of Sr, Pb (as well-established isotopic systems), Mo and B (as novel isotopic system) assessed by MC ICP-MS in water and sediment samples to study aquatic ecosystem transport processes. The isotopic variation of Sr, Pb, Mo and B was determined in different marine and estuarine compartments covering the catchment of the German Wadden Sea and its main tributaries, the Elbe, Weser and Ems River. The varying elemental concentrations, the complex matrix and the expected small variations in the isotopic composition required the development and application of reliable analytical measurement approaches as well as suited metrological data evaluation strategies. Aquatic isoscapes were created using ArcGIS® by relating spatial isotopic data with geographical and geological maps. The elemental and isotopic distribution maps show large variation for different parameters and also reflect the numerous impact factors (e.g. geology, anthropogenic sources) influencing the catchment area.

  12. MS in Your Relationships

    MedlinePlus

    ... Disease T Cells d What Causes MS? Disproved Theories Viruses Clusters d Who Gets MS? Pediatric MS ... of Distinction Lawry Circle Circle of Influence d Planned Giving d Other Ways to Give Donate by ...

  13. Sensitivity of GC-EI/MS, GC-EI/MS/MS, LC-ESI/MS/MS, LC-Ag(+) CIS/MS/MS, and GC-ESI/MS/MS for analysis of anabolic steroids in doping control.

    PubMed

    Cha, Eunju; Kim, Sohee; Kim, Ho Jun; Lee, Kang Mi; Kim, Ki Hun; Kwon, Oh-Seung; Lee, Jaeick

    2015-01-01

    This study compared the sensitivity of various separation and ionization methods, including gas chromatography with an electron ionization source (GC-EI), liquid chromatography with an electrospray ionization source (LC-ESI), and liquid chromatography with a silver ion coordination ion spray source (LC-Ag(+) CIS), coupled to a mass spectrometer (MS) for steroid analysis. Chromatographic conditions, mass spectrometric transitions, and ion source parameters were optimized. The majority of steroids in GC-EI/MS/MS and LC-Ag(+) CIS/MS/MS analysis showed higher sensitivities than those obtained with other analytical methods. The limits of detection (LODs) of 65 steroids by GC-EI/MS/MS, 68 steroids by LC-Ag(+) CIS/MS/MS, 56 steroids by GC-EI/MS, 54 steroids by LC-ESI/MS/MS, and 27 steroids by GC-ESI/MS/MS were below cut-off value of 2.0 ng/mL. LODs of steroids that formed protonated ions in LC-ESI/MS/MS analysis were all lower than the cut-off value. Several steroids such as unconjugated C3-hydroxyl with C17-hydroxyl structure showed higher sensitivities in GC-EI/MS/MS analysis relative to those obtained using the LC-based methods. The steroids containing 4, 9, 11-triene structures showed relatively poor sensitivities in GC-EI/MS and GC-ESI/MS/MS analysis. The results of this study provide information that may be useful for selecting suitable analytical methods for confirmatory analysis of steroids.

  14. Ms. Mentor Unmasked

    ERIC Educational Resources Information Center

    Krebs, Paula

    2008-01-01

    This article presents an interview with Emily Toth, who writes the monthly "Ms. Mentor" academic advice column in the "Chronicle of Higher Education" and teaches in the English department at Louisiana State University, in Baton Rouge. She is the author of "Ms. Mentor's Impeccable Advice for Women in Academia" (1997), "Inside Peyton Place: The Life…

  15. Living with Advanced MS

    MedlinePlus

    ... programs and benefits. Read More Read More Publication Managing Progressive MS An overview of symptom management, coping ... is essential to maintaining your quality of life. Managing other health conditions Compared to the general population, ...

  16. Managing Progressive MS

    MedlinePlus

    ... MS Society | 8 builders about renovations and home adaptations to support independence. OTs may also evaluate and ... Staying at home will mean making changes. Home adaptations do more than fight fatigue. They offer safety, ...

  17. MS Based Metabonomics

    SciTech Connect

    Want, Elizabeth J.; Metz, Thomas O.

    2010-03-01

    Metabonomics is the latest and least mature of the systems biology triad, which also includes genomics and proteomics, and has its origins in the early orthomolecular medicine work pioneered by Linus Pauling and Arthur Robinson. It was defined by Nicholson and colleagues in 1999 as the quantitative measurement of perturbations in the metabolite complement of an integrated biological system in response to internal or external stimuli, and is often used today to describe many non-global types of metabolite analyses. Applications of metabonomics are extensive and include toxicology, nutrition, pharmaceutical research and development, physiological monitoring and disease diagnosis. For example, blood samples from millions of neonates are tested routinely by mass spectrometry (MS) as a diagnostic tool for inborn errors of metabolism. The metabonome encompasses a wide range of structurally diverse metabolites; therefore, no single analytical platform will be sufficient. Specialized sample preparation and detection techniques are required, and advances in NMR and MS technologies have led to enhanced metabonome coverage, which in turn demands improved data analysis approaches. The role of MS in metabonomics is still evolving as instrumentation and software becomes more sophisticated and as researchers realize the strengths and limitations of current technology. MS offers a wide dynamic range, high sensitivity, and reproducible, quantitative analysis. These attributes are essential for addressing the challenges of metabonomics, as the range of metabolite concentrations easily exceeds nine orders of magnitude in biofluids, and the diversity of molecular species ranges from simple amino and organic acids to lipids and complex carbohydrates. Additional challenges arise in generating a comprehensive metabolite profile, downstream data processing and analysis, and structural characterization of important metabolites. A typical workflow of MS-based metabonomics is shown in Figure

  18. IMS - MS Data Extractor

    SciTech Connect

    2015-10-20

    An automated drift time extraction and computed associated collision cross section software tool for small molecule analysis with ion mobility spectrometry-mass spectrometry (IMS-MS). The software automatically extracts drift times and computes associated collision cross sections for small molecules analyzed using ion mobility spectrometry-mass spectrometry (IMS-MS) based on a target list of expected ions provided by the user.

  19. ICP-MS Workshop

    SciTech Connect

    Carman, April J.; Eiden, Gregory C.

    2014-11-01

    This is a short document that explains the materials that will be transmitted to LLNL and DNN HQ regarding the ICP-MS Workshop held at PNNL June 17-19th. The goal of the information is to pass on to LLNL information regarding the planning and preparations for the Workshop at PNNL in preparation of the SIMS workshop at LLNL.

  20. NAPS-MS

    PubMed Central

    Gudesblatt, Mark; Kresa-Reahl, Kiren; Brandes, David W.; Sater, Pamela

    2016-01-01

    Background: Patients with multiple sclerosis (MS) have higher rates of fatigue, mood disturbance, and cognitive impairments than healthy populations. Disease-modifying agents may affect sleep. Although patients taking natalizumab often show improvement in fatigue during the first year of therapy, the mechanism behind this effect is unknown. The aim of the NAPS-MS study was to investigate whether natalizumab affected objective measures of sleep as determined by polysomnography (PSG) and multiple sleep latency testing (MSLT) in patients with MS with fatigue or sleepiness initiating therapy. Additional goals were to evaluate changes in measures of fatigue, mood, and cognition and to correlate these measures with objective sleep measures. Methods: Patients underwent PSG and MSLT before their first natalizumab infusion and after their seventh. Patients completed the Modified Fatigue Impact Scale, Fatigue Severity Scale (FSS), Epworth Sleepiness Scale (ESS), and visual analogue scale for fatigue (VAS-F) at their first, fourth, and seventh natalizumab infusions. NeuroTrax cognitive tests and the Hospital Anxiety and Depression Scale (HADS) were performed at the first and seventh natalizumab infusions. Results: Changes in sleep efficiency, wakefulness after sleep onset, and multiple sleep latency from baseline to 6 months of therapy did not reach significance. The FSS, VAS-F, ESS, and HADS scores were significantly improved after 6 months of therapy; cognitive scores were not significantly improved. Conclusions: Although treatment with natalizumab was associated with improvements in fatigue, sleepiness, and mood, changes in objective measures of sleep were not significant. PMID:27551242

  1. API-ionspray MS and MS/MS study on the structural characterization of bisbenzylisoquinoline alkaloids.

    PubMed

    Wu, Wu Nan; Moyer, Michael D

    2004-01-27

    API-ionspray MS and MS/MS techniques have been utilized to elucidate the structures of 20 bisbenzylisoquinoline alkaloids, consisting of 17 diether and three monoether links of two benzyltetrahydroisoquinoline units, which were isolated and identified previously from a variety of Thalictrum sp. (Ranunculaceae family). Apparent protonated molecular ions ([M+H](+)) and very intense doubly-protonated molecular ion ([M+2H](++), 100% of relative abundance) in Q1 Scan MS spectra and prominent as well as diagnostic product ions for the structural information in MS/MS spectra were observed in nanogram quantities for all investigated alkaloids.

  2. MS-DIAL: data-independent MS/MS deconvolution for comprehensive metabolome analysis.

    PubMed

    Tsugawa, Hiroshi; Cajka, Tomas; Kind, Tobias; Ma, Yan; Higgins, Brendan; Ikeda, Kazutaka; Kanazawa, Mitsuhiro; VanderGheynst, Jean; Fiehn, Oliver; Arita, Masanori

    2015-06-01

    Data-independent acquisition (DIA) in liquid chromatography (LC) coupled to tandem mass spectrometry (MS/MS) provides comprehensive untargeted acquisition of molecular data. We provide an open-source software pipeline, which we call MS-DIAL, for DIA-based identification and quantification of small molecules by mass spectral deconvolution. For a reversed-phase LC-MS/MS analysis of nine algal strains, MS-DIAL using an enriched LipidBlast library identified 1,023 lipid compounds, highlighting the chemotaxonomic relationships between the algal strains.

  3. Investigation of Electromagnetic Signatures of a FPGA Using an APREL EM-ISIGHT System

    DTIC Science & Technology

    2015-12-01

    INVESTIGATION OF ELECTROMAGNETIC SIGNATURES OF A FPGA USING AN APREL EM-ISIGHT SYSTEM THESIS...States. AFIT-ENV-MS-15-D-035 INVESTIGATION OF ELECTROMAGNETIC SIGNATURES OF A FPGA USING AN APREL EM-ISIGHT SYSTEM THESIS Presented...ENV-MS-15-D-035 INVESTIGATION OF ELECTROMAGNETIC SIGNATURES OF A FPGA USING AN APREL EM-ISIGHT SYSTEM Karynn A. Sutherlin, Civilian, DAF

  4. Polyamine analysis by LC-MS.

    PubMed

    Häkkinen, Merja R

    2011-01-01

    This chapter describes a protocol to analyze polyamines without any derivatization steps utilizing LC-MS/MS. Polyamines are separated by reversed phase LC prior MS analysis using heptafluorobutyric acid as MS compatible volatile ion-pairing agent, and selective and sensitive MS detection is performed using MS/MS in selected reaction monitoring mode.

  5. MS Thornton and MS Gardner conduct DSO 410 on middeck

    NASA Technical Reports Server (NTRS)

    1983-01-01

    On middeck, Mission Specialist (MS) Thornton, his head surrounded by wiring and with electrodes attached to his face and forehead, controls instrument switch as MS Gardner, wearing headset, signals with his thumb. Procedures are part of Detailed Supplementary Objective (DSO) 410 - Audiometry. Forward lockers and starboard wall with field sequential (FS) crew cabin camera, sleep restraints, and net stowage bag appear in background.

  6. Partially isobaric peptide termini labeling assisted proteome quantitation based on MS and MS/MS signals.

    PubMed

    Zhang, Shen; Wu, Qi; Shan, Yichu; Zhou, Yuan; Zhang, Lihua; Zhang, Yukui

    2015-01-30

    Isotopic labeling and isobaric labeling are two kinds of the typical quantification method that have been widely used in proteomics analysis. Herein, a novel quantitative strategy, partially isobaric peptide termini labeling (PITL), was developed to overcome the drawbacks of each above-mentioned labeling strategy, by simultaneously collecting the quantitative information from both MS and MS/MS spectrum. PITL is based on the site-selective N-terminus dimethylation labeling of peptide α-N-termini and the free ε-amino group of lysines, resulting in the partially isobaric labeling of peptides. The relative quantification can then be achieved by comparing the intensities of precursor ions in MS spectra and a, b and y ions in MS/MS spectra. The quantitative analysis of differently labeled yeast digests pooled with various ratios indicated the good quantitative accuracy, reproducibility, coverage and wide dynamic range of PITL strategy. Furthermore, PITL was applied to the quantitative proteome analysis of two mouse hepatocarcinoma ascites syngeneic cell lines with low and high lymph node metastasis rates (Hca-F and Hca-P). Given its low cost, simple operation and good accuracy, PITL might have great potential in the quantitative proteome analysis of biological samples. The partially isobaric peptide termini labeling (PITL) method enabled to simultaneously obtain the quantitative information from MS and MS/MS spectrum, which combined the advantages of these two strategies. Relative quantification could be achieved by comparing the intensities of parent ions in MS spectra and a, b, y ions in the MS/MS spectra. The quantitative analysis for differently labeled yeast digests mixed at various ratios indicated the good accuracy, reproducibility, quantitative coverage and wide dynamic range of the PITL strategy. Finally, we found 84 differentially expressed proteins in mouse hepatocarcinoma ascites syngeneic cell lines with low and high lymph node metastasis rates with PITL

  7. Analysis of acrylamide by LC-MS/MS and GC-MS in processed Japanese foods.

    PubMed

    Ono, H; Chuda, Y; Ohnishi-Kameyama, M; Yada, H; Ishizaka, M; Kobayashi, H; Yoshida, M

    2003-03-01

    Acrylamide concentrations in processed foods (63 samples covering 31 product types) from Japan were analysed by LC-MS/MS and GC-MS methods. The limit of detection and limit of quantification of acrylamide were 0.2 ng x ml(-1) (6 fmol) and 0.8 ng x ml(-1) (22 fmol), respectively, by LC-MS/MS, and those of 2,3-dibromopropionamide derived from acrylamide were 12 ng x ml(-1) (52 fmol) and 40 ng x ml(-1) (170 fmol), respectively, by GC-MS. Repeatability given as RSD was <5 and <15% for the LC-MS/MS and GC-MS methods, respectively. High correlation (r(2) - 0.946) was observed between values obtained by the two methods. Most potato crisps and whole potato-based fried snacks showed acrylamide concentrations >1000 microg x kg(-1). The concentrations in non-whole potato-based snacks, rice crackers processed by grilling or frying, and candied sweet potatoes were lower compared with those in the potato crisps and the whole potato-based fried snacks. One of the whole potato-based fried snacks, however, showed low acrylamide concentration (<50 microg x kg(-1)) suggesting the formation of acrylamide is strongly influenced by processing conditions. Acrylamide concentrations in instant precooked noodles and won-tons were <100 microg x kg(-1) with only one exception. Roasted barley grains for 'Mugi-cha' tea contained 200-600 microg x kg(-1) acrylamide.

  8. Determination of Glyphosate Levels in Breast Milk Samples from Germany by LC-MS/MS and GC-MS/MS.

    PubMed

    Steinborn, Angelika; Alder, Lutz; Michalski, Britta; Zomer, Paul; Bendig, Paul; Martinez, Sandra Aleson; Mol, Hans G J; Class, Thomas J; Pinheiro, Nathalie Costa

    2016-02-17

    This study describes the validation and application of two independent analytical methods for the determination of glyphosate in breast milk. They are based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) and gas chromatography-tandem mass spectrometry (GC-MS/MS), respectively. For LC-MS/MS, sample preparation involved an ultrafiltration followed by chromatography on an anion exchange column. The analysis by GC-MS/MS involved an extraction step, cleanup on a cation exchange column, and derivatization with heptafluorobutanol and trifluoroacetic acid anhydride. Both methods were newly developed for breast milk and are able to quantify glyphosate residues at concentrations as low as 1 ng/mL. The methods were applied to quantify glyphosate levels in 114 breast milk samples, which had been collected from August to September of 2015 in Germany. The mothers participated at their own request and thus do not form a representative sample. In none of the investigated samples were glyphosate residues above the limit of detection found.

  9. METLIN: MS/MS metabolite data from the MAGGIE Project

    DOE Data Explorer

    METLIN is a metabolite database for metabolomics containing over 50,000 structures, it also represents a data management system designed to assist in a broad array of metabolite research and metabolite identification by providing public access to its repository of current and comprehensive MS/MS metabolite data. An annotated list of known metabolites and their mass, chemical formula, and structure are available on the METLIN website. Each metabolite is conveniently linked to outside resources such as the the Kyoto Encyclopedia of Genes and Genomes (KEGG) for further reference and inquiry. MS/MS data is also available on many of the metabolites. The list is expanding continuously as more metabolite information is being deposited and discovered. [from http://metlin.scripps.edu/] Metlin is a component of the MAGGIE Project. MAGGIE is funded by the DOE Genomics: GTL and is an acronym for "Molecular Assemblies, Genes, and Genomics Integrated Efficiently."

  10. Qualitative identification of rodenticide anticoagulants by LC-MS/MS.

    PubMed

    Middleberg, Robert A; Homan, Joseph

    2012-01-01

    Rodenticide anticoagulants are used in the control of rodent populations. In addition to accidental ingestions in humans, such agents have also been used for homicidal and suicidal purposes. There are two major groups of rodenticide anticoagulants - hydroxycoumarins and indanediones. Before the advent of LC-MS/MS, analysis for such agents was relegated to such techniques as TLC and HPLC with nonspecific modes of detection. LC-MS/MS has been used to determine any given number of rodenticide anticoagulants in animal tissues, foods, plasma, etc. Use of this technique allows for the simultaneous identification of individual compounds within both classes of rodenticide anticoagulants. The LC-MS/MS method presented allows for simultaneous qualitative identification of brodifacoum, bromadiolone, chlorphacinone, dicumarol, difenacoum, diphacinone, and warfarin in blood, serum, and plasma using ESI in the negative mode. Two transitions are monitored for each analyte after a simple sample preparation. Chromatographic separation is accomplished using a gradient of ammonium hydroxide in water and ammonium hydroxide in methanol. Chloro-warfarin is used as internal standard.

  11. Relapsing-Remitting MS (RRMS)

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  12. Finding of pesticides in fashionable fruit juices by LC-MS/MS and GC-MS/MS.

    PubMed

    Tran, Kevin; Eide, David; Nickols, Susan M; Cromer, Michele R; Sabaa-Srur, Armando; Smith, Robert E

    2012-10-15

    Products labelled as containing extracts from two mushrooms (cordyceps plus reishi) and the juices from açaí, goji, mangosteen, noni, pomegranate, and sea buckthorn have been analysed for 174 different pesticides, using the validated QuEChERS method for sample preparation and electrospray LC-MS/MS in the positive ion mode for analysis. Pesticides were found in 10 of the 21 samples analysed. Most pesticides found were below the tolerance levels (1-6 μg/g, depending on the pesticide), but some were not. This included boscalid, dimethomorph, iprovalicarb, pyridaben, pyrimethanil, and imazalil, for which there is no tolerance reported or zero tolerance in any fruit. However, genuine açaí that was harvested in the state of Pará and lyophilised in Rio de Janeiro had no detectable pesticides, when analysed by both LC-MS/MS and GC-MS/MS, which can detect 213 more pesticides and industrial chemicals. Likewise no pesticides were found in one sample each of cordyceps plus reishi, sea buckthorn and noni.

  13. ExMS: Data Analysis for HX-MS Experiments

    NASA Astrophysics Data System (ADS)

    Kan, Zhong-Yuan; Mayne, Leland; Sevugan Chetty, Palaniappan; Englander, S. Walter

    2011-11-01

    A previous paper considered the problems that presently limit the hydrogen exchange - mass spectrometry (HX-MS) method for studying the biophysical and functional properties of proteins. Many of these problems can be overcome by obtaining and analyzing hundreds of sequentially overlapping peptide fragments that cover the protein many times over (Mayne et al. J. Am. Soc. Mass Spectrom. 2011: 10.1007/s13361-011-0235-4). This paper describes a computer program called ExMS that furthers this advance by making it possible to efficiently process crowded mass spectra and definitively identify and characterize these many peptide fragments. ExMS automatically scans through high resolution MS data to find the individual isotopic peaks and isotopic envelopes of a list of peptides previously identified by MS/MS. It performs a number of tests to ensure correct identification in spite of peptide overlap in both chromatographic and mass spectrometric dimensions and possible multi-modal envelopes due to static or dynamic structural heterogeneity or HX EX1 behavior. The program can automatically process data from many sequential HX time points with no operator intervention at the rate of ~2 sec per peptide per HX time point using desktop computer equipment, but it also provides for rapid manual checking and decision when ambiguity exists. Additional subroutines can provide a step by step report of performance at each test along the way and parameter adjustment, deconvolute isotopic envelopes, and plot the time course of single and multi-modal H-D exchange. The program will be available on an open source basis at: http://HX2.med.upenn.edu/download.html

  14. Disposable chromatography for a high-throughput nano-ESI/MS and nano-ESI/MS-MS platform.

    PubMed

    Williams, Jason G; Tomer, Kenneth B

    2004-09-01

    High-throughput proteomics has typically relied on protein identification based on MALDI-MS peptide maps of proteolytic digests of 2D-gel-separated proteins. This technique, however, requires significant sequence coverage in order to achieve a high level of confidence in the identification. Tandem MS data have the advantage of requiring fewer peptides (2) for high confidence identification, assuming adequate MS/MS sequence coverage. MALDI-MS/MS techniques are becoming available, but can still be problematic because of the difficulty of inducing fragment ions of a singly charged parent ion. Electrospray ionization, however, has the advantage of generating multiply charged species that are more readily fragmented during MS/MS analysis. Two electrospray/tandem mass spectrometry-based approaches, nanovial-ESI-MS/MS and LC-MS/MS, are used for high throughput proteomics, but much less often than MALDI-MS and peptide mass fingerprinting. Nanovial introduction entails extensive manual manipulation and often shows significant chemical background from the in-gel digest. LC-MS has the advantages that the chemical background can be removed prior to analysis and the analytes are concentrated during the separation, resulting in more abundant analyte signals. On the other hand, LC-MS can often be time intensive. Here, we report the incorporation of on-line sample clean-up and analyte concentration with a high-throughput, chip-based, robotic nano-ESI-MS platform for proteomics studies.

  15. MS-MS Approaches for the Analysis of Environmental Pollutants

    EPA Science Inventory

    Concern about the environment and the start of environmental analysis coincided with the rise of gas chromatography-mass spectrometry (GC-MS). The United States Environmental Protection Agency (U.S. EPA) was founded in 1970, and as the need for techniques to analyze environmental...

  16. Modeling Contaminants in AP-MS/MS Experiments

    PubMed Central

    Lavallée-Adam, Mathieu; Cloutier, Philippe; Coulombe, Benoit; Blanchette, Mathieu

    2015-01-01

    Identification of protein–protein interactions (PPI) by affinity purification (AP) coupled with tandem mass spectrometry (AP-MS/MS) produces large data sets with high rates of false positives. This is in part because of contamination at the AP level (due to gel contamination, nonspecific binding to the TAP columns in the context of tandem affinity purification, insufficient purification, etc.). In this paper, we introduce a Bayesian approach to identify false-positive PPIs involving contaminants in AP-MS/MS experiments. Specifically, we propose a confidence assessment algorithm (called Decontaminator) that builds a model of contaminants using a small number of representative control experiments. It then uses this model to determine whether the Mascot score of a putative prey is significantly larger than what was observed in control experiments and assigns it a p-value and a false discovery rate. We show that our method identifies contaminants better than previously used approaches and results in a set of PPIs with a larger overlap with databases of known PPIs. Our approach will thus allow improved accuracy in PPI identification while reducing the number of control experiments required. PMID:21117706

  17. MS-MS Approaches for the Analysis of Environmental Pollutants

    EPA Science Inventory

    Concern about the environment and the start of environmental analysis coincided with the rise of gas chromatography-mass spectrometry (GC-MS). The United States Environmental Protection Agency (U.S. EPA) was founded in 1970, and as the need for techniques to analyze environmental...

  18. 10 years of MS instrumental developments--impact on LC-MS/MS in clinical chemistry.

    PubMed

    Himmelsbach, Markus

    2012-02-01

    The combination of liquid chromatography and mass spectrometry (LC-MS) is a powerful and indispensable analytical tool that is widely applied in many areas of chemistry, medicine, pharmaceutics and biochemistry. In this review recent MS instrumental developments are presented as part of a special issue covering various aspects of liquid chromatography tandem mass spectrometry (LC-MS/MS) in clinical chemistry. Improvements, new inventions as well as new combinations in ion source technology are described focusing on dual or multimode sources and atmospheric pressure photoionization (APPI). Increasing demands regarding sensitivity, accuracy, resolution and both quantitation and identification guarantee on-going improvements in mass analyzer technology. This paper discusses new hybrid MS instruments that can perform novel scan modes as well as high-resolution mass spectrometers (HRMS) that finally seem to be able to overcome, or at least significantly reduce, their weaknesses in quantitative applications. Ion mobility-mass spectrometry (IMMS) itself is not an invention of the last 10 years, but a lot of progress was made within the last decade that reveals the potential benefits of this combination. This is clearly reflected by the increased number of commercially available instruments and the various designs of IMMS are covered in detail in this review. Selected applications for all these instrumental developments are given focusing on the perspective of clinical chemistry.

  19. Massachusetts Small MS4 General Permit | Stormwater ...

    EPA Pesticide Factsheets

    2017-08-28

    The 2016 Massachusetts Small MS4 General Permit was signed April 4, 2016 and will become effective July 1, 2017. The final permit reflects modifications to the 2014 draft small MS4 general permit released for comment on September 30, 2014 and replaces the 2003 small MS4 general permit for MS4 operators within the Commonwealth of Massachusetts.

  20. MS/MS and LC-MS/MS analysis of choline/ethanolamine plasmalogens via promotion of alkali metal adduct formation.

    PubMed

    Otoki, Yurika; Nakagawa, Kiyotaka; Kato, Shunji; Miyazawa, Teruo

    2015-11-01

    Tandem mass spectrometry (MS/MS) has been used for the analysis of plasmalogen (Pls), a physiologically important class of vinyl ether-linked phospholipid. However, MS/MS generally causes little fragmentation of Pls, especially choline Pls (PC-Pls). Previous MS/MS studies reported an increased formation of product ions of PC-Pls (and also ethanolamine Pls (PE-Pls)) in the presence of 'alkali metals.' Therefore, use of alkali metals considerably leads to the development of a method for analysis of both PC- and PE-Pls. In this study, this notion was evaluated using quadrupole-time-of-flight MS/MS and liquid chromatography (LC) coupled with MS/MS. Results from MS/MS confirmed that alkali metals (e.g., sodium) produced significant fragmentation of PC-Pls and PE-Pls. A number of structure-diagnostic product ions exhibiting high intensities were observed under optimized MS/MS conditions using alkali metals. Moreover, the ability to selectively and sensitively identify PC-Pls and PE-Pls at the molecular species level in biological samples (rat brain and heart) was demonstrated using LC-MS/MS. Therefore, the herein developed method appears to be a powerful tool for analyzing Pls and may provide a better understanding of their physiological roles in vivo. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Evaluating GC/MS Performance

    SciTech Connect

    Alcaraz, A; Dougan, A

    2006-11-26

    Evaluating the chemical background in the GC/MS system (system background) and solvent purity. This procedure will allow the analyst to verify that the GC/MS is free of chemical interferences or contamination and verify the solvent being utilized is free of interferences - Conduct a GC/MS analysis without injecting a solvent (system background) and Conduct a GC/MS analysis inject 1uL of CH2Cl2 solvent (Solvent background). GC conditions: (1) Injector Temperature (C): Injector Temperature is typically set at 250; (2) Transferline Temperature (C) - The Transferline Temperature is typically set at 280 C; (3) Constant flow (Sec./cm2) - This value, in seconds per cubic cm. Typically, set at 32; (4) Splitless mode (Sec.) - This value, in seconds, is the time before the purge valve opens. Typically, set at 45 seconds; (5) Starting Temperature (C): The Starting Temperature value can be set at 40 C; (6) Hold Time 1 (Min.) - Hold Time 1 is the amount of time, in minutes at the Starting Temperature that Ramp 1 Temperature is held. Typically set at 3 minutes; (7) Ramp 1 Rate (C/Min.) - Ramp 1 Rate is the temperature rise per unit time and has a typically value of 8 C per minute to 300 C; and (8) Hold Time 2 (Min.): Hold Time 2 is the amount of time, in minutes at the final Temperature that Ramp 1 Temperature is held. Temperature is held at 300 C for 3 minutes. MS conditions: Electronic - 40 to 500 amu, Scan Range - 30-600 m/z, Scan time - 0.7 sec, Mass Resolution - 07u, and Electron energy 1 - 70 eV. The total ion chromatograms (TIC) from a bakeout and solvent should be void of any large chromatographic peaks (see figure 1). Autotune using the PFTBA calibrant: First selecting the autotune option and click on standard autotune. The software program will generate final tune report similar to figure 2. If there are any MS tuning problems (e.g., dirty source, air leak, etc.) the tuning process will fail. Be sure to save the tune file before proceeding to the next step. Run an 'Air

  2. CE-microreactor-CE-MS/MS for protein analysis

    PubMed Central

    Schoenherr, Regine M.; Ye, Mingliang; Vannatta, Michael

    2008-01-01

    We present a proof-of-principle for a fully automated bottom-up approach to protein characterization. Proteins are first separated by capillary electrophoresis. A pepsin microreactor is incorporated into the distal end of this capillary. Peptides formed in the reactor are transferred to a second capillary, where they are separated by capillary electrophoresis and characterized by mass spectrometry. While peptides generated from one digestion are being separated in the second capillary, the next protein fraction undergoes digestion in the microreactor. The migration time in the first dimension capillary is characteristic of the protein while migration time in the second dimension is characteristic of the peptide. Spot capacity for the two-dimensional separation is 590. A MS/MS analysis of a mixture of cytochrome C and myoglobin generated Mascot MOWSE scores of 107 for cytochrome C and 58 for myoglobin. The sequence coverages were 48% and 22%, respectively. PMID:17295444

  3. Determination of drugs in hair using GC/MS/MS.

    PubMed

    Uhl, M

    1997-01-17

    An important task for the forensic toxicologist and expert witness is the detection of the noxa in biological matrices. Because of this, the identification and quantification of residues of illegal drugs in human hair is still of growing interest. Utilizing the advantages of GC/MS/MS testing human hair is performed for most common drugs of abuse like heroin and other opioides, cocaine, cannabis and amphetamine derivatives. Analyzing hair specimens for substances that present a toxicological risk is another challenge. Several quality control parameters must be observed to avoid false positive or false negative results and to gain additional information. Blank sample, blank hair as well as the combined wash extracts are tested for the presence of the relevant compounds within every series. Careful evaluation of the findings can provide an approximate measure of the intensity of drug use in the majority of cases.

  4. Determination of paraquat in vegetables using HPLC-MS-MS.

    PubMed

    Zou, Tingting; He, Pingli; Cao, Jingjing; Li, Zhen

    2015-02-01

    A simple, sensitive, reliable and economical method was developed for the determination of paraquat (a widely used herbicide) in four edible vegetables (cabbage, lettuce, spinach and Chinese cabbage) using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS-MS). The samples were extracted with water under sonication and cleaned up by weak cation exchange solid-phase extraction. Chromatographic separation of paraquat was achieved on a hydrophilic interaction liquid chromatography column (2.1 × 100 mm, 3 µm) with a gradient program using 10 mM ammonium acetate in 0.1% formic acid and acetonitrile as mobile phase. The low salt concentration used in the eluting buffer ensured extended LC-MS analysis of paraquat in different matrices without the necessity of frequent source cleaning. The validity of the developed method was evaluated by spiking paraquat in four edible vegetables at 50 and 500 ng g(-1). Recovery ranged from 43.6 to 73.5%. The limit of detection is 0.94 ng g(-1). With the developed method, the kinetic of paraquat entering plant tissue was also evaluated.

  5. Quantitative acylcarnitine determination by UHPLC-MS/MS--Going beyond tandem MS acylcarnitine "profiles".

    PubMed

    Minkler, Paul E; Stoll, Maria S K; Ingalls, Stephen T; Kerner, Janos; Hoppel, Charles L

    2015-12-01

    Tandem MS "profiling" of acylcarnitines and amino acids was conceived as a first-tier screening method, and its application to expanded newborn screening has been enormously successful. However, unlike amino acid screening (which uses amino acid analysis as its second-tier validation of screening results), acylcarnitine "profiling" also assumed the role of second-tier validation, due to the lack of a generally accepted second-tier acylcarnitine determination method. In this report, we present results from the application of our validated UHPLC-MS/MS second-tier method for the quantification of total carnitine, free carnitine, butyrobetaine, and acylcarnitines to patient samples with known diagnoses: malonic acidemia, short-chain acyl-CoA dehydrogenase deficiency (SCADD) or isobutyryl-CoA dehydrogenase deficiency (IBD), 3-methyl-crotonyl carboxylase deficiency (3-MCC) or ß-ketothiolase deficiency (BKT), and methylmalonic acidemia (MMA). We demonstrate the assay's ability to separate constitutional isomers and diastereomeric acylcarnitines and generate values with a high level of accuracy and precision. These capabilities are unavailable when using tandem MS "profiles". We also show examples of research interest, where separation of acylcarnitine species and accurate and precise acylcarnitine quantification is necessary.

  6. PTR-MS in enology

    NASA Astrophysics Data System (ADS)

    Spitaler, Renate; Araghipour, Nooshin; Mikoviny, Tomas; Wisthaler, Armin; Via, Josef Dalla; Märk, Tilmann D.

    2007-10-01

    The present communication deals with the improvement of proton transfer reaction mass spectrometry (PTR-MS) wine headspace analyses. In contrast to previous PTR-MS investigations of wine, where wine headspace was ionized by protonated ethanol clusters, the headspace was diluted by a factor of 1:40 with N2 and ionized by H3O+ ions. This method is better suited for routine applications than the previously reported method since it is simpler, faster, and the mass spectra obtained are less complex. A test wine was mixed with ethanol and with water to yield ethanol contents ranging from 10 to 15% (v/v) and these mixtures were analyzed to assess whether any quantitative differences in the composition of volatiles were detectable. The data showed no impact of the ethanol content on the wine headspace composition. The new method was applied to eight different wine samples produced from two different grape varieties: Pinot Noir and Cabernet Sauvignon. Each variety was grown in two different locations in South Tyrol (Northern Italy) and harvested at two different dates. Quantitative (but not qualitative) differences in PTR-MS spectra between the two wine varieties were observed. Using principal component analysis of selected m/z signals differentiation between Pinot Noir and Cabernet Sauvignon samples was achievable.

  7. The potential of combining ion trap/MS/MS and TOF/MS for identification of emerging contaminants

    USGS Publications Warehouse

    Ferrer, I.; Furlong, E.T.; Heine, C.E.; Thurman, E.M.

    2002-01-01

    The use of a method combining ion trap tandem mass spectrometry (MS/MS) and time of flight mass spectrometry (TOF/MS) for identification of emerging contaminates was discussed. The two tools together complemented each other in sensitivity, fragmentation and accurate mass determination. Liquid chromatography/electrospray ionization/ion-trap tandem mass spectrometry (LC/ESI/MS/MS), in positive ion mode of operation, was used to separate and identify specific compounds. Diagnostic fragment ions were obtained for a polyethyleneglycol(PEG) homolog by ion trap MS/MS, and fragments were measured by TOF/MS. It was observed that the combined method gave an exact mass measurement that differed from the calculated mass.

  8. Selenium speciation analysis of Misgurnus anguillicaudatus selenoprotein by HPLC-ICP-MS and HPLC-ESI-MS/MS

    USDA-ARS?s Scientific Manuscript database

    Analytical methods for selenium (Se) speciation were developed using high performance liquid chromatography (HPLC) coupled to either inductively coupled plasma mass spectrometry (ICP-MS) or electrospray ionization tandem mass spectrometry (ESI-MS/MS). Separations of selenomethionine (Se-Met) and sel...

  9. Dealing with MS in Your Important Relationships

    MedlinePlus

    ... Library & Education Programs Email newsletter Resilience: Addressing the Challenges of MS Webinar & Telelearning Program Momentum Magazine Educational ... Twitter Email Family and Relationships MS poses additional challenges, but it also enriches relationships and brings people ...

  10. Bioinformatics Approach for Exploring MS/MS Proteomics Data

    SciTech Connect

    Singhal, Mudita; Klicker, Kyle R.; Chin, George; Trease, Lynn L.; Stephan, Eric G.; Gracio, Deborah K.

    2005-01-01

    The use of computer tools and technologies is unavoidable when it comes to conducting Mass Spectrometry (MS) research at any significant level. This is mainly due to the large volume of MS data and the processing rates required. Most of the existing tools focus on one particular task: be it storing and maintaining the data or visualizing the dataset to draw inferences from the data. But for the researcher the problem of manually retrieving a large dataset from a datasource and customizing it for a particular visualization application is a daunting task in itself. This paper describes the Computational Cell Environment (CCE) which is a problem-solving environment for systems biology that provides a uniform and integrated access to distributed, heterogeneous biological data sources and analysis applications, through a multi-tiered architecture. This paper also illustrates the necessity for such a tool by discussing its usage in proteomics research being performed on the diseased and normal states of Deinococcus Radiodurans along with corresponding curated data collected from community resources.

  11. EMS Student Handbook.

    ERIC Educational Resources Information Center

    Ogle, Patrick

    This student guide is one of a series of self-contained materials for students enrolled in an emergency medical services (EMS) training program. Discussed in the individual sections of the guide are the following topics: the purpose and history of EMS professionals; EMS training, certification and examinations (national and state certification and…

  12. New Help for MS Patients

    NASA Technical Reports Server (NTRS)

    1993-01-01

    The Mark VII MicroClimate Medical Personal Cooling system enables multiple sclerosis' victims, as well as cerebral palsy, spinabifida patients and others to lower their body temperatures. Although this is not a cure, cooling can produce a dramatic improvement in symptoms. The Multiple Sclerosis Association of America has placed cool suits in MS research care centers. This technology originated in the need for cooling systems in spa@esuits. "Cool Suits" are now used by hazardous materials workers, armored vehicle crews, firefighters and crop dusters. A surgical personal cooling system has also been developed for medical personnel working in hot operating room environments.

  13. Biomarker discovery by CE-MS enables sequence analysis via MS/MS with platform-independent separation.

    PubMed

    Zürbig, Petra; Renfrow, Matthew B; Schiffer, Eric; Novak, Jan; Walden, Michael; Wittke, Stefan; Just, Ingo; Pelzing, Matthias; Neusüss, Christian; Theodorescu, Dan; Root, Karen E; Ross, Mark M; Mischak, Harald

    2006-06-01

    CE-MS is a successful proteomic platform for the definition of biomarkers in different body fluids. Besides the biomarker defining experimental parameters, CE migration time and molecular weight, especially biomarker's sequence identity is an indispensable cornerstone for deeper insights into the pathophysiological pathways of diseases or for made-to-measure therapeutic drug design. Therefore, this report presents a detailed discussion of different peptide sequencing platforms consisting of high performance separation method either coupled on-line or off-line to different MS/MS devices, such as MALDI-TOF-TOF, ESI-IT, ESI-QTOF and Fourier transform ion cyclotron resonance, for sequencing indicative peptides. This comparison demonstrates the unique feature of CE-MS technology to serve as a reliable basis for the assignment of peptide sequence data obtained using different separation MS/MS methods to the biomarker defining parameters, CE migration time and molecular weight. Discovery of potential biomarkers by CE-MS enables sequence analysis via MS/MS with platform-independent sample separation. This is due to the fact that the number of basic and neutral polar amino acids of biomarkers sequences distinctly correlates with their CE-MS migration time/molecular weight coordinates. This uniqueness facilitates the independent entry of different sequencing platforms for peptide sequencing of CE-MS-defined biomarkers from highly complex mixtures.

  14. MOMA GC-MS coupling

    NASA Astrophysics Data System (ADS)

    Buch, A.; Pinnick, V. T.; Grand, N.; Szopa, C.; Danell, R.; Lustrement, B.; Freissinet, C.; van Amerom, F. H.; Raulin, F.; Glavin, D. P.; Stalport, F.; Coll, P. J.; Arevalo, R. D.; Brinckerhoff, W. B.; Goesmann, F.; Mahaffy, P. R.

    2013-12-01

    The joint ESA-Roscosmos Exo-Mars-2018 rover mission seeks the signs of past or present life on Mars. The Mars Organic Molecule Analyzer (MOMA) aboard the ExoMars rover will be a key analytical tool in providing chemical (molecular) information from the solid samples, with particular focus on the characterization of organic content. Central to MOMA instrumentation is a gas chromatograph-mass spectrometer (GC-MS) which provides the unique ability to characterize a broad range of compounds allowing chemical analyses of volatile and non-volatile species. The Gas chromatograph and the oven have been built at LATMOS/LISA (France) and at MPS (Germany) respectively whereas the mass spectrometer has been built at the NASA Goddard Space Flight Center (USA). Both instruments have been tested separately first and have been coupled in order to test the efficiency of the future MOMA GC-MS instrument. The main objective of the second step has been to test the quantitative response of both instruments while they are coupled and to characterize the combined instrument detection limit for several compounds. A final experiment has been done in order to test the feasibility of the separation and detection of a mixture contained in a soil sample introduced in the MOMA oven.

  15. The advantages of microflow LC-MS/MS compared with conventional HPLC-MS/MS for the analysis of methotrexate from human plasma.

    PubMed

    Christianson, Chad C; Johnson, Casey J L; Needham, Shane R

    2013-06-01

    In support of bioanalysis, there has always been a desire to improve detection limits and reduce scale. Microflow LC (MFLC) coupled with MS accomplishes both of these goals. As such, MFLC coupled with an MS system was used to generate bioanalytical validation data that met US FDA criteria. The MFLC-MS/MS data was compared with the same method with the use of conventional HPLC-MS/MS and a more than 14× S/N improvement was found with the MFLC-MS/MS method. Methotrexate was used as a model molecule to demonstrate the validation of the method from human plasma. The MFLC-MS/MS method was demonstrated to be accurate (±7%) and precise (12.9% at the LLOQ and a maximum of 11.6% at all other concentrations) across the dynamic range of the assay (1-1000 ng/ml) and compared well with the HPLC-MS/MS method. The MFLC bioanalytical validation was performed at a flow rate of 35 µl/min on a 0.5-mm inner diameter (I.D.) column, whereas, for the same linear velocities on the 2.0-mm I.D. column, the conventional HPLC bioanalytical validation was performed at 700 µl/min. Since the flow rate of the MFLC system is 20-times less than the HPLC system, the consumable solvent and disposal cost to perform the MFLC validation was significantly less. MFLC-MS/MS can be used to perform bioanalytical method validations with increased MS signal, reduced source contamination and reduced solvent consumption.

  16. Treatment optimization in MS: Canadian MS Working Group updated recommendations.

    PubMed

    Freedman, Mark S; Selchen, Daniel; Arnold, Douglas L; Prat, Alexandre; Banwell, Brenda; Yeung, Michael; Morgenthau, David; Lapierre, Yves

    2013-05-01

    The Canadian Multiple Sclerosis Working Group (CMSWG) developed practical recommendations in 2004 to assist clinicians in optimizing the use of disease-modifying therapies (DMT) in patients with relapsing multiple sclerosis. The CMSWG convened to review how disease activity is assessed, propose a more current approach for assessing suboptimal response, and to suggest a scheme for switching or escalating treatment. Practical criteria for relapses, Expanded Disability Status Scale (EDSS) progression and MRI were developed to classify the clinical level of concern as Low, Medium and High. The group concluded that a change in treatment may be considered in any RRMS patient if there is a high level of concern in any one domain (relapses, progression or MRI), a medium level of concern in any two domains, or a low level of concern in all three domains. These recommendations for assessing treatment response should assist clinicians in making more rational choices in their management of relapsing MS patients.

  17. EM International. Volume 1

    SciTech Connect

    Not Available

    1993-07-01

    It is the intent of EM International to describe the Office of Environmental Restoration and Waste Management`s (EM`s) various roles and responsibilities within the international community. Cooperative agreements and programs, descriptions of projects and technologies, and synopses of visits to international sites are all highlighted in this semiannual journal. Focus on EM programs in this issue is on international collaboration in vitrification projects. Technology highlights covers: in situ sealing for contaminated sites; and remote sensors for toxic pollutants. Section on profiles of countries includes: Arctic contamination by the former Soviet Union, and EM activities with Germany--cooperative arrangements.

  18. Determination of a selection of synthetic cannabinoids and metabolites in urine by UHPSFC-MS/MS and by UHPLC-MS/MS.

    PubMed

    Berg, Thomas; Kaur, Lakhwinder; Risnes, Anna; Havig, Stine Marie; Karinen, Ritva

    2016-07-01

    Two different analytical techniques, ultra-high performance supercritical fluid chromatography-tandem mass spectrometry (UHPSFC-MS/MS) and reversed phase ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS), were used for the determination of two synthetic cannabinoids and eleven metabolites in urine; AM-2201 N-4-OH-pentyl, AM-2233, JWH-018 N-5-OH-pentyl, JWH-018 N-pentanoic acid, JWH-073 N-4-OH-butyl, JWH-073 N-butanoic acid, JWH-122 N-5-OH-pentyl, MAM-2201, MAM-2201 N-4-OH-pentyl, RCS-4 N-5-OH-pentyl, UR-144 degradant N-pentanoic acid, UR-144 N-4-OH-pentyl, and UR-144 N-pentanoic acid. Sample preparation included a liquid-liquid extraction after deconjugation with ß-glucuronidase. The UHPSFC-MS/MS method used an Acquity UPC(2 TM) BEH column with a mobile phase consisting of CO2 and 0.3% ammonia in methanol, while the UHPLC-MS/MS method used an Acquity UPLC® BEH C18 column with a mobile phase consisting of 5 mM ammonium formate (pH 10.2) and methanol. MS/MS detection was performed with positive electrospray ionization and two multiple reaction monitoring transitions. Deuterated internal standards were used for six of the compounds. Limits of quantification (LOQs) were between 0.04 and 0.4 µg/L. Between-day relative standard deviations at concentrations ≥ LOQ were ≤20%, with biases within ±19%. Recoveries ranged from 40 to 90%. Corrected matrix effects were within 100 ± 10%, except for MAM-2201 with UHPSFC-MS/MS, and for UR-144 N-pentanoic acid and MAM-2201 N-4-OH-pentyl with UHPLC-MS/MS. Elution order obtained by UHPSFC-MS/MS was almost opposite to that obtained by UHPLC-MS/MS, making this instrument setup an interesting combination for screening and confirmation analyses in forensic cases. The UHPLC-MS/MS method has, since August 2014, been successfully used for confirmation of synthetic cannabinoids in urine samples revealing a positive immunoassay screening result. Copyright © 2015

  19. Use of an integrated MS--multiplexed MS/MS data acquisition strategy for high-coverage peptide mapping studies.

    PubMed

    Chakraborty, Asish B; Berger, Scott J; Gebler, John C

    2007-01-01

    Liquid chromatography/mass spectrometry (LC/MS) peptide maps have become a basic tool for characterizing proteins of biological and pharmaceutical interest. The ability to generate reproducible maps with high protein sequence coverage is a central goal of methods development. We have applied a recently developed analytical approach (termed LC/MS(E)) to LC/MS peptide mapping. Using the LC/MS(E) approach, the mass detector alternates between a low-energy scanning mode (MS) for accurate mass peptide precursor identification, and an elevated-energy mode (MS(E)) for generation of accurate mass multiplex peptide fragmentation data. In this paper, we evaluate this analytical approach against a tryptic digest of yeast enolase. From the low-energy data, high peptide map coverage (98% of sequence from peptides >3 amino acids) was reproducibly obtained. The MS signal for essentially equimolar peptides varied over 2 orders of magnitude in intensity, and peptide intensities could be precisely and reproducibly measured. Using the temporal constraint that MS(E) peptide fragment ions exhibit chromatographic profiles that parallel the precursor ions that generated them, we were able to produce accurate mass time-resolved MS/MS information for all enolase peptides with sufficient abundance to produce a detectable fragment ion. Copyright (c) 2007 John Wiley & Sons, Ltd.

  20. Analysis of phytochemical variations in dioecious Tinospora cordifolia stems using HPLC/QTOF MS/MS and UPLC/QqQLIT -MS/MS.

    PubMed

    Bajpai, Vikas; Singh, Awantika; Chandra, Preeti; Negi, M P S; Kumar, Nikhil; Kumar, Brijesh

    2016-01-01

    The stem of dioecious Tinospora cordifolia (Menispermaceae) is a commonly used traditional Ayurvedic medicine in India having several therapeutic properties. To develop and validate LC-MS methods for the identification and simultaneous quantitation of various secondary metabolites and to study metabolomic variations in the stem of male and female plants. Ethanolic extract of stems were analysed by HPLC/ESI-QTOF-MS/MS for rapid screening of bioactive phytochemicals. High resolution MS and MS/MS in positive ESI mode were used for structural investigation of secondary metabolites. An UPLC/ESI-QqQ(LIT) -MS/MS method in MRM mode was developed and validated for the simultaneous quantitation of five bioactive alkaloids. Identification and characterisation of 36 metabolites including alkaloids, sesquiterpenes and phytoecdysteroids were performed using LC-MS and MS/MS techniques. The bioactive alkaloids such as jatrorrhizine, magnoflorine, isocorydine, palmatine and tetrahydropalmatine were successfully quantified in male and female plants. The mean abundances of magnoflorine jatrorrhizine, and oblongine were significantly (P < 0.05) higher in male plants while mean abundances of tetrahydropalmatine, norcoclaurine, and reticuline were significantly (P < 0.05) higher in female plants. Phytochemicals in the stem of male and female Tinospora cordifolia showed significant qualitative and quantitative variations. LC-MS and MS/MS methods can be used to differentiate between male and female plants based on their chemical profiles and quantities of the marker bioactive alkaloids. This chemical composition difference was also evident during vegetative stage when there were no male and female flowers. Copyright © 2015 John Wiley & Sons, Ltd.

  1. The Immortality of Ms Jones

    PubMed Central

    Gallagher, Timothy

    2014-01-01

    When I began my medical student clinical rotations, I quickly became overwhelmed by feelings of inadequacy. While the doctors around me conjured appropriate diagnoses and treatment approaches, I fumbled with the only tools I possessed: my time and a smile. It was only when I met the patient Ms Jones that I came to understand the potential impact of these simple tools. My encouragement became part of her recovery process. She gave me the confidence to construct this ability of comforting patients into a small platform of confidence from which I could safely venture to educate patients or suggest treatments to residents. It could be something that I could reliably fall back on in times of doubt and something I could pass along to other people I met. PMID:25024247

  2. The immortality of Ms Jones.

    PubMed

    Gallagher, Timothy

    2014-07-01

    When I began my medical student clinical rotations, I quickly became overwhelmed by feelings of inadequacy. While the doctors around me conjured appropriate diagnoses and treatment approaches, I fumbled with the only tools I possessed: my time and a smile. It was only when I met the patient Ms Jones that I came to understand the potential impact of these simple tools. My encouragement became part of her recovery process. She gave me the confidence to construct this ability of comforting patients into a small platform of confidence from which I could safely venture to educate patients or suggest treatments to residents. It could be something that I could reliably fall back on in times of doubt and something I could pass along to other people I met.

  3. PTR-MS and GC-MS Analyses of Sesquiterpenes

    NASA Astrophysics Data System (ADS)

    Rasmussen, R. A.; Geron, C.; Goldstein, A. H.; Holzinger, R.; Lee, A.

    2003-12-01

    Terpene hydrocarbons are ubiquitous compounds in the atmosphere. Frits Went, in 1960 suggested that the volatile organic emissions from plants especially the monoterpenes were responsible for the formation of the atmosphere's `blue haze'. Surveys of plant emissions using a Proton Transfer Reaction - Mass Spectrometer (PTR-MS) have shown that many species emit sesquiterpenes (Ssqt's) independent of emitting monoterpenes or isoprene. It is possible they are a comparable source of the organic micro-aerosols responsible for scattering the blue end of the spectrum, i.e. `blue haze' in addition to the monoterpenes as they have more rapid and complete reactions with ozone resulting in particles. Ambient concentrations of the terpenic hydrocarbons are site dependent, but are typically very low from a few to 1000 pptCv, except for isoprene which has summer mid-day median levels of 3 to 6 ppbCv. The sesquiterpenes are very difficult to measure in the atmosphere by conventional means but cubebene, copaene, bourbonene and alpha- and beta-caryophyllene are common foliage emissions. Direct measurements of isoprene, monoterpenes and sesquiterpenes over plant foliages with a PTR-MS were compared with captive samples of the air from the same plant foliages collected in Summa canisters. None of the biogenic organic emissions stored in the Summa canisters showed any significant losses due to wall effects. Neither did we observe that any of the processing steps were responsible for losses or internal molecular rearrangements. The reason for the stability and 100% recovery of these C5 to C15 olefinic compounds at room temperature is believed to be due to the water layer formed on the electropolished stainless steel walls of the canister under pressure at 30 psig. Ozone added to the test systems was observed to have an immediate effect on the sesquiterpenes at ambient levels. Measurements made this past summer at the Duke and Blodgett Research Forests again confirm that the ambient

  4. Profiling cytosine oxidation in DNA by LC-MS/MS.

    PubMed

    Samson-Thibault, Francois; Madugundu, Guru S; Gao, Shanshan; Cadet, Jean; Wagner, J Richard

    2012-09-17

    Spontaneous and oxidant-induced damage to cytosine is probably the main cause of CG to TA transition mutations in mammalian genomes. The reaction of hydroxyl radical (·OH) and one-electron oxidants with cytosine derivatives produces numerous oxidation products, which have been identified in large part by model studies with monomers and short oligonucleotides. Here, we developed an analytical method based on LC-MS/MS to detect 10 oxidized bases in DNA, including 5 oxidation products of cytosine. The utility of this method is demonstrated by the measurement of base damage in isolated calf thymus DNA exposed to ionizing radiation in aerated aqueous solutions (0-200 Gy) and to well-known Fenton-like reactions (Fe(2+) or Cu(+) with H(2)O(2) and ascorbate). The following cytosine modifications were quantified as modified 2'-deoxyribonucleosides upon exposure of DNA to ionizing radiation in aqueous aerated solution: 5-hydroxyhydantoin (Hyd-Ura) > 5-hydroxyuracil (5-OHUra) > 5-hydroxycytosine (5-OHCyt) > 5,6-dihydroxy-5,6-dihydrouracil (Ura-Gly) > 1-carbamoyl-4,5-dihydroxy-2-oxoimidazolidine (Imid-Cyt). The total yield of cytosine oxidation products was comparable to that of thymine oxidation products (5,6-dihydroxy-5,6-dihydrothymine (Thy-Gly), 5-hydroxy-5-methylhydantotin (Hyd-Thy), 5-(hydroxymethyl)uracil (5-HmUra), and 5-formyluracil (5-ForUra)) as well as the yield of 8-oxo-7,8-dihydroguanine (8-oxoGua). The major oxidation product of cytosine in DNA was Hyd-Ura. In contrast, the formation of Imid-Cyt was a minor pathway of DNA damage, although it is the major product arising from irradiation of the monomers, cytosine, and 2'-deoxycytidine. The reaction of Fenton-like reagents with DNA gave a different distribution of cytosine derived products compared to ionizing radiation, which likely reflects the reaction of metal ions with intermediate peroxyl radicals or hydroperoxides. The analysis of the main cytosine oxidation products will help elucidate the complex

  5. Advances in quantifying apolipoproteins using LC-MS/MS technology: implications for the clinic.

    PubMed

    van den Broek, Irene; Sobhani, Kimia; Van Eyk, Jennifer E

    2017-10-01

    Apolipoproteins play a key role in pre-, pro-, and anti-atherosclerotic processes and have become important circulating biomarkers for the prediction of cardiovascular disease (CVD) risk. Whereas currently clinical immunoassays are not available for most apolipoproteins and lack the capacity for multiplexing, liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) allows simultaneous, highly-specific, and precise quantification of multiple apolipoproteins. Areas covered: We discuss LC-MS/MS methods for quantification of apolipoproteins reported in the literature and highlight key requirements for clinical use. Besides the advances in sample preparation and LC-MS/MS technologies, this overview also discusses advances in proteoform analysis and applications of dried blood/plasma collection. Expert commentary: Standardized quantification using LC-MS/MS technology has been demonstrated for apolipoprotein A-I and B. However, for implementation in clinical CVD risk assessment, LC-MS/MS must bring significant added clinical value in comparison to fast, standardized, and straightforward clinical (immuno)assays. Ongoing advances in accuracy and multiplexing capacity of LC-MS/MS, nonetheless, bear potential to enable standardized and interpretable personalized profiling of a patient's CVD risk by simultaneous quantification of multiple apolipoproteins and -variants. We, moreover, anticipate further personalization of CVD risk assessment by the potential of LC-MS/MS to enable simultaneous genotyping and remote monitoring using dried blood/plasma collection devices.

  6. LC-MS systems for quantitative bioanalysis.

    PubMed

    van Dongen, William D; Niessen, Wilfried M A

    2012-10-01

    LC-MS has become the method-of-choice in small-molecule drug bioanalysis (molecular mass <800 Da) and is also increasingly being applied as an alternative to ligand-binding assays for the bioanalytical determination of biopharmaceuticals. Triple quadrupole MS is the established bioanalytical technique due to its unpreceded selectivity and sensitivity, but high-resolution accurate-mass MS is recently gaining ground due to its ability to provide simultaneous quantitative and qualitative analysis of drugs and their metabolites. This article discusses current trends in the field of bioanalytical LC-MS (until September 2012), and provides an overview of currently available commercial triple quadrupole MS and high-resolution LC-MS instruments as applied for the bioanalysis of small-molecule and biopharmaceutical drugs.

  7. LC-MS/MS in the Clinical Laboratory – Where to From Here?

    PubMed Central

    Grebe, Stefan KG; Singh, Ravinder J

    2011-01-01

    Liquid chromatography-tandem mass spectrometry (LC-MS/MS) has seen enormous growth in clinical laboratories during the last 10–15 years. It offers analytical specificity superior to that of immunoassays or conventional high performance/pressure liquid chromatography (HPLC) for low molecular weight analytes and has higher throughput than gas chromatography-mass spectrometry (GC-MS). Drug/Toxicology and Biochemical Genetics/Newborn Screening laboratories were at the vanguard of clinical LC-MS/MS use, but have been eclipsed by Endocrine laboratories. In USA reference/referral laboratories, most steroids and biogenic amines are now assayed by LC-MS/MS, and the technology has started to penetrate into smaller laboratories. Assays for mineralo- and gluco-corticoids and their precursors, sex steroids, metanephrines and 25-hydroxy vitamin D highlight the advantages of LC-MS/MS. However, several limitations of LC-MS/MS have become apparent, centring on the interacting triangle of sensitivity – specificity – throughput. While sample throughput is higher than for conventional HPLC or GC-MS, it lags behind automated immunoassays. Techniques which improve throughput include direct sample injection, LC-multiplexing and samplemultiplexing. Measures to improve specificity and sensitivity include sample clean-up and optimising chromatography to avoid interferences and ion suppression due to sample-matrix components. Next generation instrumentation may offer additional benefits. The next challenge for clinical LC-MS/MS is peptide/protein analysis. The quest for multi-biomarker profiles for various diseases has largely failed, but targeted peptide and protein testing by LC-MS/MS, directed at analytical and clinical questions that need to be answered, is proving highly successful. We anticipate that this will result in similar growth of clinical protein/peptide LC-MS/MS as has been seen for low molecular weight applications. PMID:21451775

  8. Leveraging EMS and VPP

    DTIC Science & Technology

    2009-05-01

    Elements of EMS  International Standards Organization ( ISO ) 14001 , Environmental Management Systems  The Key Elements of EMS: - Policy - Planning...wingman-- ON and OFF duty Fully Conforming vs. Fully Implemented  “Fully Conforming”  Meets standards established in ISO 14001  ESOH council...e n c e Every airman looking out for his wingman-- ON and OFF duty EMS & VPP Commonalities Environmental Management System ISO 14001 : 2004 Voluntary

  9. Repeated exposure of goldfish (Carassius auratus) to tricaine methanesulfonate (MS-222).

    PubMed

    Posner, Lysa Pam; Scott, Gregory N; Law, J McHugh

    2013-06-01

    Goldfish that have been repeatedly exposed to tricaine methanesulfonate (MS-222) require greater concentration of the drug to attain equivalent planes of anesthesia, but the mechanism for this increased anesthetic need is unknown. Minimum anesthetic concentration (MAC) is a commonly used method with which to compare anesthetics. It was hypothesized that fish exposed to MS-222 daily would have an increased MAC. It was also hypothesized that fish exposed daily to MS-222 would develop histomorphologic changes to their gills to explain the increasing demand. Forty-nine Serasa comet goldfish were enrolled and were divided into three populations (n = 15, n = 15, and n = 19). In trial 1, using an up-down method, MAC was determined daily after 4 min of exposure to MS-222 for which the starting concentration was 160 mg/L. In trial 2, MAC was determined following 2 min of exposure to MS-222 for which the starting concentration was 260 mg/L. In trial 3, four naive fish were euthanatized and gills collected for histology and electron microscopy (EM). The remaining fish were exposed to MS-222 daily for 4 wk. Four fish were euthanatized and their gills submitted for similar examination at 2 wk and 4 wk. MAC for fish exposed to MS-222 for 4 min increased from 120 to 160 mg/L. The regression line had a slope of 1.51 +/- 0.26 (R2 = 0.65; P < 0.0001). MAC for fish exposed to MS-222 for 2 min increased from 210 pmm to 220 mg/L; the regression line had a slope of 0.52 +/- 0.38 (R2 = 0.12; P = 0.2). Histologic and EM examination of gills did not show morphologic changes indicative of a reaction to MS-222. Goldfish in this study had an increased requirement for MS-222 following daily exposure for 4 min but not following daily exposure for 2 min at a higher concentration. The cause of this increased anesthetic need is not related to morphologic changes to the gills.

  10. Analysis of complex protein mixtures with improved sequence coverage using (CE-MS/MS)n.

    PubMed

    Garza, Selynda; Moini, Mehdi

    2006-10-15

    Identification of proteins, in a complex protein mixture, using one-dimensional high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) analysis of its digest, usually suffers from low sequence coverage. There are several reasons for the low coverage including undersampling, wide concentration dynamic range of the proteins in a complex protein mixture, and wide range of electrospray ionization efficiency of peptides under each mobile-phase composition. To address this low sequence coverage, we introduce a novel technique, (CE-MS/MS)n, which utilizes the most significant advantages of CE-MS/MS, including economy of sample size, fast analysis time, and high separation efficiency, to increase the sequence coverage of a complex protein mixture. Based on these characteristics, (CE-MS/MS)n can be performed in which multiple CE-MS/MS subanalyses (injections followed by analyses) are analyzed and experimental variables are manipulated during each CE-MS/MS subanalysis in order to maximize sequence coverage. (CE-MS/MS)n is a practical technique since each CE-MS/MS subanalysis consumes <10 nL, and each CE-MS/MS subanalysis takes approximately 10 min; therefore, several subanalyses can be performed in approximately 1 h consuming only nanoliters of the sample. Two techniques have been introduced to address the undersampling: (1) (CE-MS/MS)n using dynamic exclusion. In this technique, several CE-MS/MS analyses (injection followed by separation) were performed in one run using the dynamic exclusion capability of the mass spectrometer until all peptide peaks were analyzed by MS/MS. (2) Gas-phase fractionation. In this technique, (CE-MS/MS)n is performed by scanning a narrow mass range (every approximately 100 m/z) during each CE-MS/MS subanalysis without using dynamic exclusion. Under this condition, in each subanalysis, the number of peptides available for MS/MS analysis is significantly reduced, and peptides with the same nominal masses are analyzed, thereby

  11. A Comparison of nLC-ESI-MS/MS and nLC-MALDI-MS/MS for GeLC-based Protein Identification and iTRAQ-based Shotgun Quantitative Proteomics

    USDA-ARS?s Scientific Manuscript database

    The use of nLC-ESI-MS/MS in shotgun proteomics experiments and GeLC-MS/MS analysis is well accepted and routinely available in most proteomics laboratories. However, the same cannot be said for nLC-MALDI MS/MS, which has yet to experience such widespread acceptance despite the fact that the MALDI t...

  12. LC-MS/MS analysis of steroids in the clinical laboratory.

    PubMed

    Keevil, Brian G

    2016-09-01

    Liquid chromatography-tandem mass spectrometry (LC-MS/MS) is a powerful tool that is changing the way we analyse steroids in the clinical laboratory. It is already opening up the field of steroid analysis in endocrinology and is providing new applications for individual steroids and panels of steroids in different clinical conditions. LC-MS/MS is now well-accepted technology and is increasingly being used to replace problematic immunoassay methods because of greater sensitivity and specificity. Improved sample preparation, modern chromatography methods, and sensitive, faster scanning mass spectrometers have all played a role in improving LC-MS/MS. LC-MS/MS is also playing a key role in improving the quality of assays through the development of reference measurement procedures, characterisation of reference materials and multi-site calibration programmes. There is increasing interest in multiplexing steroid assays into panels of diagnostic tests to aid and improve the diagnosis and monitoring of disease.

  13. [Method for determination of histamine in food by LC-MS/MS].

    PubMed

    Ohtsubo, Yoshito; Kurooka, Hiroyuki; Tada, Hisae; Manabe, Noboru

    2014-01-01

    In Japan, a criterion value of histamine residue in food is not clearly defined and there is no official test method. We examined histamine in fish and fish products according to the food sanitation test guideline (fluorescence derivatization of histamine with dansyl chloride and quantification by LC-FL: the LC-FL method). Positive samples were confirmed by determining dansylated histamine using our developed LC-MS/MS procedure (the LC-MS/MS method) when histamine was detected. Validation was earried out according to the validation test guideline using fresh fish. Recovery tests of histamine from fresh fish spiked at the level of 20 ppm were carried out. The limit of quantification was 5 ppm. The results confirmed that our LC-MS/MS method is applicable for the inspection of fish and fish products. This LC-MS/MS method has a lower false-positive ratio and a higher selectivity than the LC-FL method.

  14. Gadofosveset: MS 325, MS 32520, Vasovist, ZK 236018.

    PubMed

    2004-01-01

    Gadofosveset [MS 325, MS 32520, Vasovist, ZK 236018], a gadolinium-based chelate, is an injectable angiography imaging agent for use in magnetic resonance imaging (MRI) scans. The agent is being developed by EPIX Medical (formerly Metasyn) for diagnostic imaging of blood vessels of the cardiovascular system. Gadofosveset has potential as an alternative to the range of x-ray, invasive, catheter-based angiograms and thallium stress tests currently used in the diagnosis of coronary artery disease. The agent may also have applications in the diagnosis of peripheral vascular disease, thrombosis and breast cancer. Unlike conventional MRI contrast agents, gadofosveset binds to serum albumin in the blood and moves with the blood through the arteries and veins for an extended period of time before being excreted by the kidneys. The MRI with gadofosveset allows 3D images of the whole body to be accessed in one imaging session. Moreover, it makes it possible to view vessel structures.EPIX Medical has acquired an exclusive licence from the Massachusetts General Hospital to a certain technology, including patents and patent applications, that relates to the company's product candidates such as gadofosveset.EPIX Medical, Mallinckrodt (Tyco International) and Schering AG signed several agreements to develop, manufacture and market gadofosveset (formerly known as Mallinckrodt's AngioMARK). Initially, in June 2000 Schering AG acquired worldwide exclusive rights (except for Japan) from EPIX Medical to develop and market gadofosveset. Under the terms of the agreement, EPIX Medical is responsible for the completion of clinical trials and filing for approval in the US, while Schering AG undertakes responsibility for clinical investigation of gadofosveset outside the US. Mallinckrodt is responsible and will undertake a long-term supply contract for gadofosveset for clinical development and sales. Schering's subsidiary Berlex will market the product in the US after the approval via its

  15. LC-MS/MS Method for Serum Creatinine: Comparison with Enzymatic Method and Jaffe Method

    PubMed Central

    Li, Shuijun; Liu, Gangyi; Jia, Jingying; Zhang, Menqi; Zhang, Haichen; Yu, Chen

    2015-01-01

    Accurate quantification of creatinine (Cre) is important to estimate glomerular filtration rate (GFR). Differences among various methods of Cre quantification were previously noted. This study aims to develop a liquid chromatography tandem mass spectrometry (LC-MS/MS) method for serum Cre and compare this method with clinical routine methods. LC-MS/MS analysis was performed on API 4000 triple quadrupole mass spectrometer coupled with an Agilent 1200 liquid chromatography system. After adding isotope-labeled Cre-d3 as internal standard, serum samples were prepared via a one-step protein precipitation with methanol. The LC-MS/MS method was compared with frequently used enzymatic method and Jaffe method. This developed method, with a total run time of 3 min, had a lower limit of quantification of 4.4 μmol/L, a total imprecision of 1.15%–3.84%, and an average bias of 1.06%. No significant matrix effect, carryover, and interference were observed for the LC-MS/MS method. The reference intervals of serum Cre measured by LC-MS/MS assay were 41–79 μmol/L for adult women, and 46–101 μmol/L for adult men. Using LC-MS/MS as a reference, the enzymatic method showed an average bias of -2.1% and the Jaffe method showed a substantial average bias of 11.7%. Compared with the LC-MS/MS method, significant negative bias was observed for the enzymatic and Jaffe methods in hemolytic and lipimic samples. We developed a simple, specific, and accurate LC-MS/MS method to analyze serum Cre. Discordance existed among different methods. PMID:26207996

  16. A touch of MS: therapeutic mislabeling.

    PubMed

    Boissy, Adrienne R; Ford, Paul J

    2012-06-12

    When psychogenic symptomatology is at play, a spectrum of ethical problems and considerations arise when patients want, and at times, insist on being given an inaccurate neurologic diagnosis. We use the example of multiple sclerosis (MS) to highlight the value considerations for clinicians when they face these types of cases. Given the ambiguities involved in its diagnosis and the significant risks of its treatment, MS represents a rich case study. This discussion highlights the potential harms of mislabeling such patients with MS when the neurologist is confident they do not have MS and offers suggestions about how to approach and manage these patients. Despite being expedient and well-intentioned, labeling psychogenic symptoms with a medically inaccurate diagnosis, such as a "touch of MS," constitutes a "therapeutic mislabeling" and sacrifices ethically important values incommensurate with the benefits gained.

  17. Efficient Modeling of MS/MS Data for Metabolic Flux Analysis.

    PubMed

    Tepper, Naama; Shlomi, Tomer

    2015-01-01

    Metabolic flux analysis (MFA) is a widely used method for quantifying intracellular metabolic fluxes. It works by feeding cells with isotopic labeled nutrients, measuring metabolite isotopic labeling, and computationally interpreting the measured labeling data to estimate flux. Tandem mass-spectrometry (MS/MS) has been shown to be useful for MFA, providing positional isotopic labeling data. Specifically, MS/MS enables the measurement of a metabolite tandem mass-isotopomer distribution, representing the abundance in which certain parent and product fragments of a metabolite have different number of labeled atoms. However, a major limitation in using MFA with MS/MS data is the lack of a computationally efficient method for simulating such isotopic labeling data. Here, we describe the tandemer approach for efficiently computing metabolite tandem mass-isotopomer distributions in a metabolic network, given an estimation of metabolic fluxes. This approach can be used by MFA to find optimal metabolic fluxes, whose induced metabolite labeling patterns match tandem mass-isotopomer distributions measured by MS/MS. The tandemer approach is applied to simulate MS/MS data in a small-scale metabolic network model of mammalian methionine metabolism and in a large-scale metabolic network model of E. coli. It is shown to significantly improve the running time by between two to three orders of magnitude compared to the state-of-the-art, cumomers approach. We expect the tandemer approach to promote broader usage of MS/MS technology in metabolic flux analysis.

  18. Metabolomics data normalization with EigenMS.

    PubMed

    Karpievitch, Yuliya V; Nikolic, Sonja B; Wilson, Richard; Sharman, James E; Edwards, Lindsay M

    2014-01-01

    Liquid chromatography mass spectrometry has become one of the analytical platforms of choice for metabolomics studies. However, LC-MS metabolomics data can suffer from the effects of various systematic biases. These include batch effects, day-to-day variations in instrument performance, signal intensity loss due to time-dependent effects of the LC column performance, accumulation of contaminants in the MS ion source and MS sensitivity among others. In this study we aimed to test a singular value decomposition-based method, called EigenMS, for normalization of metabolomics data. We analyzed a clinical human dataset where LC-MS serum metabolomics data and physiological measurements were collected from thirty nine healthy subjects and forty with type 2 diabetes and applied EigenMS to detect and correct for any systematic bias. EigenMS works in several stages. First, EigenMS preserves the treatment group differences in the metabolomics data by estimating treatment effects with an ANOVA model (multiple fixed effects can be estimated). Singular value decomposition of the residuals matrix is then used to determine bias trends in the data. The number of bias trends is then estimated via a permutation test and the effects of the bias trends are eliminated. EigenMS removed bias of unknown complexity from the LC-MS metabolomics data, allowing for increased sensitivity in differential analysis. Moreover, normalized samples better correlated with both other normalized samples and corresponding physiological data, such as blood glucose level, glycated haemoglobin, exercise central augmentation pressure normalized to heart rate of 75, and total cholesterol. We were able to report 2578 discriminatory metabolite peaks in the normalized data (p<0.05) as compared to only 1840 metabolite signals in the raw data. Our results support the use of singular value decomposition-based normalization for metabolomics data.

  19. EPA CRL MS014: Analysis of Aldicarb, Bromadiolone, Carbofuran, Oxamyl and Methomyl in Water by Multiple Reaction Monitoring Liquid Chromatography / Tandem Mass Spectrometry (LC/MS/MS)

    EPA Pesticide Factsheets

    Method MS014 describes procedures for solvent extraction of aldicarb, bromadiolone, carbofuran, oxamyl and methomyl from water samples, followed by analysis using liquid chromatography tandem mass spectrometry (LC-MS-MS).

  20. Automated precursor ion exclusion during LC-MS/MS data acquisition for optimal ion identification.

    PubMed

    Zhang, Zhongqi

    2012-08-01

    Liquid chromatography-tandem mass spectrometry (LC-MS/MS) is widely used for characterizing multiple samples of complex mixtures with similar compositions. This article addresses a data acquisition strategy for collecting a maximal number of unique, high-quality MS/MS during LC-MS/MS analysis of multiple samples. Based on the concept that a component only needs to be identified once when analyzing multiple samples with similar compositions, an automated intersample data-dependent acquisition strategy was developed. The strategy is based on precursor ion exclusion (PIE) and is implemented in MassAnalyzer in an automated fashion for Thermo Scientific (San Jose, CA, USA) mass spectrometers. In this method, MassAnalyzer submits one sample at a time to the sample queue. After data acquisition of each sample, MassAnalyzer automatically analyzes the data to generate a PIE list based on the MS/MS precursor ions, merges this list with the list generated from previous runs, adds the list to the MS method file, and submits the next sample to the queue. The PIE list contains both m/z value and time window for each precursor ion, and is generated intelligently so that if an MS/MS is insufficient for identifying the peak of interest, it will be collected again near the top of the peak in the next run. Therefore, the strategy maximizes both quality and the number of unique MS/MS. When automated PIE was used to acquire LC-MS/MS data of an antibody tryptic digest and a soy hydrolysate sample, the number of identified ions increased by 52% and 93%, respectively, compared with data acquired without using PIE.

  1. LC-MS/MS and GC-MS methods in propofol detection: Evaluation of the two analytical procedures.

    PubMed

    Vaiano, Fabio; Serpelloni, Giovanni; Focardi, Martina; Fioravanti, Alessia; Mari, Francesco; Bertol, Elisabetta

    2015-11-01

    Propofol is a short-acting hypnotic agent that is commonly used to induce and maintain anesthesia. Propofol abuse and its involvement in suicide deaths have increased in recent years, especially among healthcare personnel. An example is the suicide of a 61-year-old nurse found with a propofol drip in his left arm. We describe the postmortem concentration of propofol in various tissues (femoral and cardiac blood, bile, urine, brain, and liver) and in the drip. The toxicological analyses were performed through two analytical methods, differing in derivatization reaction and in instrumentation: silylation for gas chromatograph-mass spectrometer (GC-MS), as routinely performed in our laboratory for this kind of analyses (lower limits of quantification-LLOQ-in urine and blood: 0.3 and 5ng/ml); for liquid chromatograph-tandem mass spectrometer (LC-MS/MS) an innovative azo-coupling derivatization (LLOQ: 0.0004 and 0.1ng/ml). This latter produces an azo-derivative (molecular composition: C18H22ON2; molecular weight: 282Da) highly ionizable in electro-spray ion source, both in negative and positive ionizations. These two methods were compared to evaluate the effectiveness of this new LC-MS/MS analysis. An acidic hydrolysis (HCl 6N, 100°C, and 1h) was performed for the biological samples (1ml or 1g) irrespective of the analytical method applied. The drip content was extracted adding phosphate buffer (pH 8) and a dichloromethane/ethylacetate 8:2 (v:v) mixture. Derivatization steps were: silylation with N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA)+tetramethylammonium hydroxide (TMAH) for GC-MS; regarding LC-MS/MS, azo-coupling reaction with the aryl-diazonium salt (0-5°C, and 30min). The analyses were achieved in selected-ion monitoring for GC-MS (m/z, 235,250,73 propofol"; m/z, 252,267,27 propofol-d17) and in multiple reaction monitoring ([M-H](-): m/z 283→241,77, azo-propofol; m/z 299→251,77, azo-propofol-d17) for LC-MS/MS. Autopsy showed no significant findings

  2. Applications and challenges in using LC-MS/MS assays for quantitative doping analysis.

    PubMed

    Wang, Zhanliang; Lu, Jianghai; Zhang, Yinong; Tian, Ye; Yuan, Hong; Xu, Youxuan

    2016-06-01

    LC-MS/MS is useful for qualitative and quantitative analysis of 'doped' biological samples from athletes. LC-MS/MS-based assays at low-mass resolution allow fast and sensitive screening and quantification of targeted analytes that are based on preselected diagnostic precursor-product ion pairs. Whereas LC coupled with high-resolution/high-accuracy MS can be used for identification and quantification, both have advantages and challenges for routine analysis. Here, we review the literature regarding various quantification methods for measuring prohibited substances in athletes as they pertain to World Anti-Doping Agency regulations.

  3. The Neurophysiologist Perspective into MS Plasticity

    PubMed Central

    Houdayer, Elise; Comi, Giancarlo; Leocani, Letizia

    2015-01-01

    Multiple sclerosis (MS) is a frequent, highly debilitating inflammatory demyelinating disease, starting to manifest in early adulthood and presenting a wide variety of symptoms, which are often resistant to pharmacological treatments. Cortical dysfunctions have been demonstrated to be key components of MS condition, and plasticity of the corticospinal motor system is highly involved in major MS symptoms, such as fatigue, spasticity, or pain. Cortical dysfunction in MS can be studied with neurophysiological tools, such as electroencephalography (EEG) and related techniques (evoked potentials) or transcranial magnetic stimulation (TMS). These techniques are now widely used to provide essential elements of MS diagnosis and can also be used to modulate plasticity. Indeed, the recent development of non-invasive brain stimulation techniques able to induce cortical plasticity, such as repetitive TMS or transcranial direct current stimulation, has brought promising results as add-on treatments. In this review, we will focus on the use of these tools (EEG and TMS) to study plasticity in MS and on the major techniques used to modulate plasticity in MS. PMID:26388835

  4. MS/MS networking guided analysis of molecule and gene cluster families

    PubMed Central

    Nguyen, Don Duy; Wu, Cheng-Hsuan; Moree, Wilna J.; Lamsa, Anne; Medema, Marnix H.; Zhao, Xiling; Gavilan, Ronnie G.; Aparicio, Marystella; Atencio, Librada; Jackson, Chanaye; Ballesteros, Javier; Sanchez, Joel; Watrous, Jeramie D.; Phelan, Vanessa V.; van de Wiel, Corine; Kersten, Roland D.; Mehnaz, Samina; De Mot, René; Shank, Elizabeth A.; Charusanti, Pep; Nagarajan, Harish; Duggan, Brendan M.; Moore, Bradley S.; Bandeira, Nuno; Palsson, Bernhard Ø.; Pogliano, Kit; Gutiérrez, Marcelino; Dorrestein, Pieter C.

    2013-01-01

    The ability to correlate the production of specialized metabolites to the genetic capacity of the organism that produces such molecules has become an invaluable tool in aiding the discovery of biotechnologically applicable molecules. Here, we accomplish this task by matching molecular families with gene cluster families, making these correlations to 60 microbes at one time instead of connecting one molecule to one organism at a time, such as how it is traditionally done. We can correlate these families through the use of nanospray desorption electrospray ionization MS/MS, an ambient pressure MS technique, in conjunction with MS/MS networking and peptidogenomics. We matched the molecular families of peptide natural products produced by 42 bacilli and 18 pseudomonads through the generation of amino acid sequence tags from MS/MS data of specific clusters found in the MS/MS network. These sequence tags were then linked to biosynthetic gene clusters in publicly accessible genomes, providing us with the ability to link particular molecules with the genes that produced them. As an example of its use, this approach was applied to two unsequenced Pseudoalteromonas species, leading to the discovery of the gene cluster for a molecular family, the bromoalterochromides, in the previously sequenced strain P. piscicida JCM 20779T. The approach itself is not limited to 60 related strains, because spectral networking can be readily adopted to look at molecular family–gene cluster families of hundreds or more diverse organisms in one single MS/MS network. PMID:23798442

  5. MS/MS networking guided analysis of molecule and gene cluster families.

    PubMed

    Nguyen, Don Duy; Wu, Cheng-Hsuan; Moree, Wilna J; Lamsa, Anne; Medema, Marnix H; Zhao, Xiling; Gavilan, Ronnie G; Aparicio, Marystella; Atencio, Librada; Jackson, Chanaye; Ballesteros, Javier; Sanchez, Joel; Watrous, Jeramie D; Phelan, Vanessa V; van de Wiel, Corine; Kersten, Roland D; Mehnaz, Samina; De Mot, René; Shank, Elizabeth A; Charusanti, Pep; Nagarajan, Harish; Duggan, Brendan M; Moore, Bradley S; Bandeira, Nuno; Palsson, Bernhard Ø; Pogliano, Kit; Gutiérrez, Marcelino; Dorrestein, Pieter C

    2013-07-09

    The ability to correlate the production of specialized metabolites to the genetic capacity of the organism that produces such molecules has become an invaluable tool in aiding the discovery of biotechnologically applicable molecules. Here, we accomplish this task by matching molecular families with gene cluster families, making these correlations to 60 microbes at one time instead of connecting one molecule to one organism at a time, such as how it is traditionally done. We can correlate these families through the use of nanospray desorption electrospray ionization MS/MS, an ambient pressure MS technique, in conjunction with MS/MS networking and peptidogenomics. We matched the molecular families of peptide natural products produced by 42 bacilli and 18 pseudomonads through the generation of amino acid sequence tags from MS/MS data of specific clusters found in the MS/MS network. These sequence tags were then linked to biosynthetic gene clusters in publicly accessible genomes, providing us with the ability to link particular molecules with the genes that produced them. As an example of its use, this approach was applied to two unsequenced Pseudoalteromonas species, leading to the discovery of the gene cluster for a molecular family, the bromoalterochromides, in the previously sequenced strain P. piscicida JCM 20779(T). The approach itself is not limited to 60 related strains, because spectral networking can be readily adopted to look at molecular family-gene cluster families of hundreds or more diverse organisms in one single MS/MS network.

  6. MUSCLE: automated multi-objective evolutionary optimization of targeted LC-MS/MS analysis.

    PubMed

    Bradbury, James; Genta-Jouve, Grégory; Allwood, J William; Dunn, Warwick B; Goodacre, Royston; Knowles, Joshua D; He, Shan; Viant, Mark R

    2015-03-15

    Developing liquid chromatography tandem mass spectrometry (LC-MS/MS) analyses of (bio)chemicals is both time consuming and challenging, largely because of the large number of LC and MS instrument parameters that need to be optimized. This bottleneck significantly impedes our ability to establish new (bio)analytical methods in fields such as pharmacology, metabolomics and pesticide research. We report the development of a multi-platform, user-friendly software tool MUSCLE (multi-platform unbiased optimization of spectrometry via closed-loop experimentation) for the robust and fully automated multi-objective optimization of targeted LC-MS/MS analysis. MUSCLE shortened the analysis times and increased the analytical sensitivities of targeted metabolite analysis, which was demonstrated on two different manufacturer's LC-MS/MS instruments.

  7. EMS in the pueblos.

    PubMed

    Vigil, M A

    1994-02-01

    Imagine creating a movie by excerpting scenes from "Dances With Wolves," splicing it with footage from "Code 3" or "Emergency Response" and then flavoring the script with the mystery of a Tony Hillerman novel. A film producer would probably find it quite difficult to choreograph a finished product from such a compilation of material. To hundreds of Native American EMS providers, however, such a movie is played out every day in Indian country. And with this movie come some real-life problems, including trauma, which is the number-one cause of premature death among Native Americans. But a high trauma rate is just one of the challenges facing tribal EMS responders. There's also prolonged response and transport, the problems involved in maintaining the unique culture and standard of care, the challenges of tribal EMS administration and EMS education of Native American students, and the unsure future of Native American EMS. Beyond that, there's the fact that EMS is a s unique to each Indian reservation as are the cultures of the native peoples who reside on these lands. Yet while no two systems are alike, most tribal EMS providers face similar challenges.

  8. NLRP3 Inflammasome and MS/EAE

    PubMed Central

    Shinohara, Mari L.

    2013-01-01

    Inflammasomes are cytosolic sensors that detect pathogens and danger signals in the innate immune system. The NLRP3 inflammasome is currently the most fully characterized inflammasome and is known to detect a wide array of microbes and endogenous damage-associated molecules. Possible involvement of the NLRP3 inflammasome (or inflammasomes) in the development of multiple sclerosis (MS) was suggested in a number of studies. Recent studies showed that the NLRP3 inflammasome exacerbates experimental autoimmune encephalomyelitis (EAE), an animal model of MS, although EAE can also develop without the NLRP3 inflammasome. In this paper, we discuss the NLRP3 inflammasome in MS and EAE development. PMID:23365725

  9. Positive and negative ion mode ESI-MS and MS/MS for studying drug-DNA complexes

    NASA Astrophysics Data System (ADS)

    Rosu, Frédéric; Pirotte, Sophie; Pauw, Edwin De; Gabelica, Valérie

    2006-07-01

    We report systematic investigation of duplex DNA complexes with minor groove binders (Hoechsts 33258 and 33342, netropsin and DAPI) and intercalators (daunomycin, doxorubicin, actinomycin D, ethidium, cryptolepine, neocryptolepine, m-Amsacrine, proflavine, ellipticine and mitoxantrone) by ESI-MS and ESI-MS/MS in the negative ion mode and in the positive ion mode. The apparent solution phase equilibrium binding constants can be determined by measuring relative intensities in the ESI-MS spectrum. While negative ion mode gives reliable results, positive ion mode gives a systematic underestimation of the binding constants and even a complete suppression of the complexes for intercalators lacking functional groups capable of interacting in the grooves. In the second part of the paper we systematically compare MS/MS fragmentation channels and breakdown curves in the positive and the negative modes, and discuss the possible uses and caveats of MS/MS in drug-DNA complexes. In the negative mode, the drugs can be separated in three groups: (1) those that leave the complex with no net charge; (2) those that leave the complex with a negative charge; and (3) those that remain attached on the strands upon dissociation of the duplex due to their positive charge. In the positive ion mode, all complexes fragment via the loss of protonated drug. Information on the stabilization of the complex by drug-DNA noncovalent interactions can be obtained straightforwardly only in the case of neutral drug loss. In all other cases, proton affinity (in the positive ion mode), gas-phase basicity (in the negative ion mode) and coulombic repulsion are the major factors influencing the fragmentation channel and the dissociation kinetics.

  10. Analysis of Thiodiglycol: Validation of Semi-Volatile Analysis by HPLC-MS/MS by EPA Method MS777

    SciTech Connect

    Owens, J; Koester, C

    2008-07-24

    The Environmental Protection Agency's (EPA) Region 5 Chicago Regional Laboratory (CRL) developed a method for the analysis of thiodiglycol, the breakdown product of the sulfur mustard HD, in water by high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS), titled Method EPA MS777 (hereafter referred to as EPA CRL SOP MS777). This draft standard operating procedure (SOP) was distributed to multiple EPA laboratories and to Lawrence Livermore National Laboratory, which was tasked to serve as a reference laboratory for EPA's Environmental Reference Laboratory Network (ERLN) and to develop and validate analytical procedures. The primary objective of this study was to verify the analytical procedures described in MS777 for analysis of thiodiglycol in aqueous samples. The gathered data from this study will be used to: (1) demonstrate analytical method performance; (2) generate quality control acceptance criteria; and (3) revise the SOP to provide a validated method that would be available for use during a homeland security event. The data contained in this report will be compiled, by EPA CRL, with data generated by other EPA Regional laboratories so that performance metrics of Method EPA MS777 can be determined.

  11. In Vivo Metabolism Study of Xiamenmycin A in Mouse Plasma by UPLC-QTOF-MS and LC-MS/MS

    PubMed Central

    Lei, Feng; Gao, Du; Zhang, Xi; Xu, Jun; Xu, Min-Juan

    2015-01-01

    Xiamenmycin A is an antifibrotic leading compound with a benzopyran skeleton that is isolated from mangrove-derived Streptomyces xiamenensis. As a promising small molecule for fibrotic diseases, less information is known about its metabolic characteristics in vivo. In this study, the time-course of xiamenmycin A in mouse plasma was investigated by relative quantification. After two types of administration of xiamenmycin A at a single dose of 10 mg/kg, the plasma concentrations were measured quantitatively by LC-MS/MS. The dynamic changes in the xiamenmycin A concentration showed rapid absorption and quick elimination in plasma post-administration. Four metabolites (M1–M4) were identified in blood by UPLC-QTOF-MS, and xiamenmycin B (M3) is the principal metabolite in vivo, as verified by comparison of the authentic standard sample. The structures of other metabolites were identified based on the characteristics of their MS and MS/MS data. The newly identified metabolites are useful for understanding the metabolism of xiamenmycin A in vivo, aiming at the development of an anti-fibrotic drug candidate for the therapeutic treatment of excessive fibrotic diseases. PMID:25636156

  12. Using the MMPB technique to confirm microcystin concentrations in water measured by ELISA and HPLC (UV, MS, MS/MS).

    PubMed

    Foss, Amanda J; Aubel, Mark T

    2015-09-15

    Microcystins have been detected in raw and finished drinking water using a variety of techniques, including assays (immunoassay, phosphatase inhibition) and HPLC (UV, MS/(MS)). The principal challenge to microcystin analysis is accounting for the over 150 variants that have been described. A confirmatory individual variant HPLC analysis is prone to under-reporting total microcystins due to method specificity. One method that allows for total microcystin quantitation is the MMPB technique. In this study, water samples with native microcystins were oxidized to cleave the Adda moiety, common to all microcystin variants. LC-MS/MS analysis was conducted on the subsequent MMPB (3-methoxy-2-methyl-4-phenylbutyric acid) molecule and calibrated using a certified reference standard (microcystin-LR) and 4-phenylbutyric acid. Total microcystin concentrations from MMPB were compared to Adda ELISA and individual variant analyses (LC-UV, LC-MS/(MS)). Variants of microcystin, including [DAsp(3)]MC-RR, [Dha(7)]MC-RR, MC-RR, MC-YR, MC-LR, [DAsp(3)]MC-LR, [Dha(7)]MC-LR, MC-WR, MC-LA, and MC-LY were detected and quantified in samples. The individual variant analyses did not account for total microcystins present in samples, as indicated by ELISA and MMPB data. Results demonstrated the MMPB technique is a simple and valuable approach to confirm ELISA data when analyzing microcystins, with method detection limits of 0.05 μg L(-1) for total microcystins.

  13. CLaMS: Classifier for Metagenomic Sequences

    SciTech Connect

    Pati, Amrita

    2010-12-01

    CLaMS-"Classifer for Metagenonic Sequences" is a Java application for binning assembled metagenomes wings user-specified training sequence sets and other user-specified initial parameters. Since ClAmS analyzes and matches sequence composition-based genomic signatures, it is much faster than binning tools that rely on alignments to homologs; CLaMS can bin ~20,000 sequences in 3 minutes on a laptop with a 2.4 Ghz. Intel Core 2 Duo processor and 2 GB Ram. CLaMS is meant to be desktop application for biologist and can be run on any machine under any operating system on which the Java Runtime Environment is enabled. CLaMS is freely available in both GVI-based and command-line based forms.

  14. At Home with MS: Adapting Your Environment

    MedlinePlus

    ... MS Accessibility Determine how many levels of living space there are inside and outside your home. Identify ... Mobility aids need a certain amount of open space to maneuver. Canes, crutches, and walkers need ample ...

  15. Thirsk with FPEF MS hardware in Kibo

    NASA Image and Video Library

    2009-10-07

    ISS020-E-048792 (7 Oct. 2009) --- Canadian Space Agency astronaut Robert Thirsk, Expedition 20/21 flight engineer, holds Fluid Physics Experiment Facility/Marangoni Surface (FPEF MS) Core hardware in the Kibo laboratory of the International Space Station.

  16. Two Time Point MS Lesion Segmentation in Brain MRI: An Expectation-Maximization Framework

    PubMed Central

    Jain, Saurabh; Ribbens, Annemie; Sima, Diana M.; Cambron, Melissa; De Keyser, Jacques; Wang, Chenyu; Barnett, Michael H.; Van Huffel, Sabine; Maes, Frederik; Smeets, Dirk

    2016-01-01

    Purpose: Lesion volume is a meaningful measure in multiple sclerosis (MS) prognosis. Manual lesion segmentation for computing volume in a single or multiple time points is time consuming and suffers from intra and inter-observer variability. Methods: In this paper, we present MSmetrix-long: a joint expectation-maximization (EM) framework for two time point white matter (WM) lesion segmentation. MSmetrix-long takes as input a 3D T1-weighted and a 3D FLAIR MR image and segments lesions in three steps: (1) cross-sectional lesion segmentation of the two time points; (2) creation of difference image, which is used to model the lesion evolution; (3) a joint EM lesion segmentation framework that uses output of step (1) and step (2) to provide the final lesion segmentation. The accuracy (Dice score) and reproducibility (absolute lesion volume difference) of MSmetrix-long is evaluated using two datasets. Results: On the first dataset, the median Dice score between MSmetrix-long and expert lesion segmentation was 0.63 and the Pearson correlation coefficient (PCC) was equal to 0.96. On the second dataset, the median absolute volume difference was 0.11 ml. Conclusions: MSmetrix-long is accurate and consistent in segmenting MS lesions. Also, MSmetrix-long compares favorably with the publicly available longitudinal MS lesion segmentation algorithm of Lesion Segmentation Toolbox. PMID:28066162

  17. Two Time Point MS Lesion Segmentation in Brain MRI: An Expectation-Maximization Framework.

    PubMed

    Jain, Saurabh; Ribbens, Annemie; Sima, Diana M; Cambron, Melissa; De Keyser, Jacques; Wang, Chenyu; Barnett, Michael H; Van Huffel, Sabine; Maes, Frederik; Smeets, Dirk

    2016-01-01

    Purpose: Lesion volume is a meaningful measure in multiple sclerosis (MS) prognosis. Manual lesion segmentation for computing volume in a single or multiple time points is time consuming and suffers from intra and inter-observer variability. Methods: In this paper, we present MSmetrix-long: a joint expectation-maximization (EM) framework for two time point white matter (WM) lesion segmentation. MSmetrix-long takes as input a 3D T1-weighted and a 3D FLAIR MR image and segments lesions in three steps: (1) cross-sectional lesion segmentation of the two time points; (2) creation of difference image, which is used to model the lesion evolution; (3) a joint EM lesion segmentation framework that uses output of step (1) and step (2) to provide the final lesion segmentation. The accuracy (Dice score) and reproducibility (absolute lesion volume difference) of MSmetrix-long is evaluated using two datasets. Results: On the first dataset, the median Dice score between MSmetrix-long and expert lesion segmentation was 0.63 and the Pearson correlation coefficient (PCC) was equal to 0.96. On the second dataset, the median absolute volume difference was 0.11 ml. Conclusions: MSmetrix-long is accurate and consistent in segmenting MS lesions. Also, MSmetrix-long compares favorably with the publicly available longitudinal MS lesion segmentation algorithm of Lesion Segmentation Toolbox.

  18. Immunoassay or LC-MS/MS for the measurement of salivary cortisol in children?

    PubMed

    Bae, Yoon Ju; Gaudl, Alexander; Jaeger, Sonia; Stadelmann, Stephanie; Hiemisch, Andreas; Kiess, Wieland; Willenberg, Anja; Schaab, Michael; von Klitzing, Kai; Thiery, Joachim; Ceglarek, Uta; Döhnert, Mirko; Kratzsch, Juergen

    2016-05-01

    Dysregulation of the adrenal cortex has been assessed with measurement of salivary cortisol. So far salivary cortisol is routinely measured with immunoassay (IA). However, liquid chromatography-tandem mass spectrometry (MS) is known to offer better specificity. We compared the concentrations of salivary cortisol measured by MS and IA at basal and stress induced conditions and evaluated reasons for the difference in method-dependent cortisol results. Saliva samples (n=2703) were collected from 169 children (age range: 8-14 years; 81 healthy children; 55 with internalizing and 33 with externalizing disorders) under circadian conditions and during the Trier Social Stress Test for Children (TSST-C). Biochemical analyses were performed with MS for cortisol and cortisone, IA (IBL, RE62011) for cortisol, and enzyme kinetic assay for α-amylase. MS and IA showed mostly comparable results for circadian activity and TSST-C response with similar statistical power. However, IA measured cortisol concentrations about 2.39-fold higher than MS. We found that this difference in measured values between MS and IA was mainly due to different standardization of IA compared to MS. In addition, at cortisol IA concentration below 5 nmol/L, cross-reactivity with cortisone was found to contribute to the lower concordance between MS and IA. Immunoassay and LC-MS/MS were largely comparable in the interpretation of salivary cortisol dynamics in stress research. But the IA method revealed a restricted accuracy in the measuring range below 5 nmol/L.

  19. High-Speed MALDI MS/MS Imaging Mass Spectrometry Using Continuous Raster Sampling

    PubMed Central

    Prentice, Boone M.; Chumbley, Chad W.; Caprioli, Richard M.

    2015-01-01

    A matrix-assisted laser desorption/ionization time of flight/time of flight tandem mass spectrometer (MALDI TOF/TOF) has been used for high-speed precursor/fragment ion transition image acquisition. High throughput analysis is facilitated by a Nd:YLF solid state laser capable of pulse repetition rates up to 5 kHz, a high digitizer acquisition rate (up to 50 pixels/second), and continuous laser raster sampling. MS/MS experiments are enabled through the use of a precision timed ion selector, second source acceleration, and a dedicated collision cell. Continuous raster sampling is shown here to facilitate rapid MS/MS ion image acquisition from thin tissue sections for the drug rifampicin and of a common kidney lipid, SM4s(d18:1/24:1). The ability to confirm the structural identity of an analyte as part of the MS/MS imaging experiment is an essential part of the analysis. Additionally, the increase in sensitivity and specificity afforded by an MS/MS approach is highly advantageous, especially when interrogating complex chemical environments such as those in biological tissues. Herein, we report continuous laser raster sampling TOF/TOF imaging methodologies which demonstrate 8-14 fold increases in throughput compared to existing MS/MS instrumentation, an important advantage when imaging large areas on tissues. PMID:26149115

  20. Determination of zinc pyrithione in shampoos by HPLC and HPLC-MS/MS.

    PubMed

    Gu, Yu-Xiang; Wang, Qing-He; Zhou, Ze-Lin; Lv, Qing; Mai, Cheng-Hua

    2014-01-01

    Methods have been developed for the determination of zinc pyrithione (ZPT) in shampoos using high-performance liquid chromatography (HPLC) and high-performance liquid chromatography-mass spectrometry/mass spectrometry (HPLC-MS/MS). Samples were washed by water first to remove surfactant and water-soluble impurities, then ultrasonic-extracted by acetonitrile-methanol for 30 min, and finally analyzed by MG C18 column (250 mm x 4.6 mm, 5 μm) or RP-18e (100 mm x 3 mm, 2 μm) plus APCI-MS/MS. Limits of detection were determined as 0.015% (HPLC) and 0.003% (HPLC-MS/MS), with a limit of quantization of 0.05% and 0.01%, respectively. The recoveries were 85.8-104% (HPLC) and 87.6-107% (HPLC-MS/MS). A good linear relationship was obtained from 3.20 μg·ml(-1) to 200 μg·ml(-1) (HPLC) and 1.00 μg·ml(-1) to 200 μg·ml(-1) (HPLC-MS/MS). The proposed methods have been successfully applied to the analysis of ZPT in many shampoos. The established two methods were rapid and reproducible with low interference.

  1. Simultaneous analysis of 17 diuretics in dietary supplements by HPLC and LC-MS/MS.

    PubMed

    Woo, H; Kim, J W; Han, K M; Lee, J H; Hwang, I S; Lee, J H; Kim, J; Kweon, S J; Cho, S; Chae, K R; Han, S Y; Kim, J

    2013-01-01

    In order to test health foods for illegally added diuretics for weight loss, we developed simple, rapid, selective, and sensitive methods using HPLC and LC-MS/MS for the simultaneous analysis of 17 diuretics in dietary supplements. HPLC conditions were set with a Capcell-pak C18, using a mobile phase consisting of gradient conditions, UV detection at 254 nm and validated for linearity (r(2)> 0.999), precision (CV ≤ 3%), recoveries (90.4-102.8%) and reproducibility. Identification and quantification of 17 diuretics were accomplished by ion-spray LC-MS/MS using multiple reaction monitoring (MRM). The chromatographic separation was carried out under the reversed-phase mechanism on an HSS-T3 column. The LC-MS/MS method was validated for linearity (r(2)> 0.99) and precision (CV < 13%). Sixteen dietary supplements were tested with the developed methods. Diuretics were not detected in all samples. Extraction recovery was also investigated and the extraction recoveries in different formulations were from 88% to 110% and from 81% to 116% using HPLC and LC-MS/MS, respectively. There was no significant difference in recoveries in the type of dietary supplements. Based on this result, the developed methods to monitor illegal drug adulterations in dietary supplements using HPLC and LC-MS/MS are simple, fast and reliable. Therefore, it is applicable to routine drug-adulteration screening.

  2. Expert System for Computer-assisted Annotation of MS/MS Spectra*

    PubMed Central

    Neuhauser, Nadin; Michalski, Annette; Cox, Jürgen; Mann, Matthias

    2012-01-01

    An important step in mass spectrometry (MS)-based proteomics is the identification of peptides by their fragment spectra. Regardless of the identification score achieved, almost all tandem-MS (MS/MS) spectra contain remaining peaks that are not assigned by the search engine. These peaks may be explainable by human experts but the scale of modern proteomics experiments makes this impractical. In computer science, Expert Systems are a mature technology to implement a list of rules generated by interviews with practitioners. We here develop such an Expert System, making use of literature knowledge as well as a large body of high mass accuracy and pure fragmentation spectra. Interestingly, we find that even with high mass accuracy data, rule sets can quickly become too complex, leading to over-annotation. Therefore we establish a rigorous false discovery rate, calculated by random insertion of peaks from a large collection of other MS/MS spectra, and use it to develop an optimized knowledge base. This rule set correctly annotates almost all peaks of medium or high abundance. For high resolution HCD data, median intensity coverage of fragment peaks in MS/MS spectra increases from 58% by search engine annotation alone to 86%. The resulting annotation performance surpasses a human expert, especially on complex spectra such as those of larger phosphorylated peptides. Our system is also applicable to high resolution collision-induced dissociation data. It is available both as a part of MaxQuant and via a webserver that only requires an MS/MS spectrum and the corresponding peptides sequence, and which outputs publication quality, annotated MS/MS spectra (www.biochem.mpg.de/mann/tools/). It provides expert knowledge to beginners in the field of MS-based proteomics and helps advanced users to focus on unusual and possibly novel types of fragment ions. PMID:22888147

  3. MS Thagard conducts DSO 404 on middeck

    NASA Technical Reports Server (NTRS)

    1983-01-01

    On middeck, Mission Specialist (MS) Thagard conducts Detailed Supplementary Objective (DSO) 404 - On Orbit Head and Eye Tracking Tasks. In MS seat positioned with seat back on the floor and headrest at starboard wall, Thagard, wearing unicorn cap (pantograph attached) and with electrodes on his face and forehead, monitors DC Ampere (Amp) control box. Forward lockers, intravehicular (IVA) foot restraint, and stowed treadmill appear in view.

  4. Ecological Epigenetics: Beyond MS-AFLP.

    PubMed

    Schrey, Aaron W; Alvarez, Mariano; Foust, Christy M; Kilvitis, Holly J; Lee, Jacob D; Liebl, Andrea L; Martin, Lynn B; Richards, Christina L; Robertson, Marta

    2013-08-01

    Ecological Epigenetics studies the relationship between epigenetic variation and ecologically relevant phenotypic variation. As molecular epigenetic mechanisms often control gene expression, even across generations, they may impact many evolutionary processes. Multiple molecular epigenetic mechanisms exist, but methylation of DNA so far has dominated the Ecological Epigenetic literature. There are several molecular techniques used to screen methylation of DNA; here, we focus on the most common technique, methylation-sensitive-AFLP (MS-AFLP), which is used to identify genome-wide methylation patterns. We review studies that used MS-AFLP to address ecological questions, that describe which taxa have been investigated, and that identify general trends in the field. We then discuss, noting the general themes, four studies across taxa that demonstrate characteristics that increase the inferences that can be made from MS-AFLP data; we suggest that future MS-AFLP studies should incorporate these methods and techniques. We then review the short-comings of MS-AFLP and suggest alternative techniques that might address some of these limitations. Finally, we make specific suggestions for future research on MS-AFLP and identify questions that are most compelling and tractable in the short term.

  5. Fast MS/MS acquisition without dynamic exclusion enables precise and accurate quantification of proteome by MS/MS fragment intensity

    PubMed Central

    Zhang, Shen; Wu, Qi; Shan, Yichu; Zhao, Qun; Zhao, Baofeng; Weng, Yejing; Sui, Zhigang; Zhang, Lihua; Zhang, Yukui

    2016-01-01

    Most currently proteomic studies use data-dependent acquisition with dynamic exclusion to identify and quantify the peptides generated by the digestion of biological sample. Although dynamic exclusion permits more identifications and higher possibility to find low abundant proteins, stochastic and irreproducible precursor ion selection caused by dynamic exclusion limit the quantification capabilities, especially for MS/MS based quantification. This is because a peptide is usually triggered for fragmentation only once due to dynamic exclusion. Therefore the fragment ions used for quantification only reflect the peptide abundances at that given time point. Here, we propose a strategy of fast MS/MS acquisition without dynamic exclusion to enable precise and accurate quantification of proteome by MS/MS fragment intensity. The results showed comparable proteome identification efficiency compared to the traditional data-dependent acquisition with dynamic exclusion, better quantitative accuracy and reproducibility regardless of label-free based quantification or isobaric labeling based quantification. It provides us with new insights to fully explore the potential of modern mass spectrometers. This strategy was applied to the relative quantification of two human disease cell lines, showing great promises for quantitative proteomic applications. PMID:27198003

  6. Petroleum crude oil characterization by IMS-MS and FTICR MS.

    PubMed

    Fernandez-Lima, Francisco A; Becker, Christopher; McKenna, Amy M; Rodgers, Ryan P; Marshall, Alan G; Russell, David H

    2009-12-15

    Here, complementary ion mobility/mass spectrometry (IM/MS) and ultrahigh-resolution Fourier transform ion cyclotron resonance (FTICR) MS analyses of light, medium, and heavy petroleum crude oils yielded distributions of the heteroatom-containing hydrocarbons, as well as multiple conformational classes. The IM/MS technique provides unique fingerprints for fast identification of signature conformational/compositional patterns, whereas FTICR MS analysis provides comprehensive heteroatom class distributions. IM/MS and FTICR MS results reveal an increase in compositional complexity in proceeding from light to medium to heavy crude oils. Inspection of the mobility results shows a high structural diversity for the C(n)H(h)XY (XY = N(1), S(1), N(1), O(1), NS, SO(1-2), NO(1-2), etc.) series, as well as a shift from planar to more compact three-dimensional structures with increasing mass.

  7. Nano LC-MS/MS: a robust setup for proteomic analysis.

    PubMed

    Gaspari, Marco; Cuda, Giovanni

    2011-01-01

    Nanoscale liquid chromatography coupled to tandem mass spectrometry (nano LC-MS/MS) has become an essential tool in the field of proteomics. In fact, its sensitivity has advantages over conventional LC-MS/MS that allow the analysis of peptide mixtures in sample-limited situations (e.g., proteolytically digested proteins isolated by two-dimensional gel electrophoresis). Technical challenges, associated with low flow rates of the chromatographic separation, make this technology still difficult to run routinely. Here, we describe a nano LC-MS/MS setup that allows several weeks of continuous operation for the analysis of peptides derived by enzymatic digestion of either purified proteins or moderately complex protein mixtures.

  8. Enantioselective quantification of chiral drugs in human plasma with LC-MS/MS.

    PubMed

    Liu, Ke; Zhong, Dafang; Chen, Xiaoyan

    2009-06-01

    Today, approximately 60% of synthetic drugs are chiral and 88% of these chiral synthetic drugs are used therapeutically as racemates. However, for many racemic drugs, their stereospecific plasma pharmacokinetics in humans are not known due to the limitations of the analytical methods. Nowadays, liquid chromatography (LC)-tandem mass spectrometry (MS/MS) methods based on various chiral stationary phases (CSPs), with a high degree of specificity and sensitivity, have been widely used in enantioselective determination of chiral drugs and/or their metabolites in human plasma. The technologies and issues when coupling chiral chromatography with MS/MS detection in bioanalytical methods will be reviewed herein. The introduction and applications of various CPSs, including polysaccharide-, macrocyclic glycopeptide-, protein- and cyclodextrin-based phases, are described here. This review also includes a discussion of interface and matrix effects in enantioselective LC-MS/MS methods.

  9. OpenMS and TOPP: open source software for LC-MS data analysis.

    PubMed

    Reinert, Knut; Kohlbacher, Oliver

    2010-01-01

    The automatic analysis of mass spectrometry data is becoming more and more important since increasingly larger datasets are readily available that cannot be evaluated manually. This has triggered the development of several open-source software libraries for the automatic analysis of such data. Among those is OpenMS together with TOPP (The OpenMS Proteomics Pipeline). OpenMS is a C++ library for rapid prototyping of complex algorithms for the analysis of mass spectrometry data. Based on the OpenMS library, TOPP provides a collection of tools for the most important tasks in proteomics analysis. The tight coupling of OpenMS and TOPP makes it easy to extend TOPP by adding new tools to the OpenMS library. We describe the overall concepts behind the software and illustrate its use with several examples.

  10. Online nanoscale ERLIC-MS outperforms RPLC-MS for shotgun proteomics in complex mixtures.

    PubMed

    de Jong, Ebbing P; Griffin, Timothy J

    2012-10-05

    We have explored the use of electrostatic repulsion hydrophilic interaction chromatography (ERLIC) as an alternative to the gold-standard in shotgun proteomics: reversed-phase (RP) LC for online ESI-MS/MS. Conditions for sample solubilization and initial gradient conditions were optimized to strike a balance between peptide solubility and maximum peptide retention when using mobile phase with high organic solvent concentration. Online ERLIC-MS demonstrated a 57% increase in total peptide identifications compared to RP-MS. We examined the mechanism of this improved performance and found that it stems from ERLIC's propensity to retain longer peptides, which can be identified with greater confidence. Online nanoscale ERLIC-MS provides a powerful new tool for enhancing MS-based shotgun proteomic in a broad range of applications.

  11. Application of LC/MS/MS Techniques to Development of US ...

    EPA Pesticide Factsheets

    This presentation will describe the U.S. EPA’s drinking water and ambient water method development program in relation to the process employed and the typical challenges encountered in developing standardized LC/MS/MS methods for chemicals of emerging concern. The EPA’s Drinking Water Contaminant Candidate List and Unregulated Contaminant Monitoring Regulations, which are the driving forces behind drinking water method development, will be introduced. Three drinking water LC/MS/MS methods (Methods 537, 544 and a new method for nonylphenol) and two ambient water LC/MS/MS methods for cyanotoxins will be described that highlight some of the challenges encountered during development of these methods. This presentation will provide the audience with basic understanding of EPA's drinking water method development program and an introduction to two new ambient water EPA methods.

  12. Isolation and characterization of a male fertility gene (Ms4) in soybean

    USDA-ARS?s Scientific Manuscript database

    Identifying a stable male-sterility system is crucial for the development of hybrid soybean. In soybean, eleven male-sterile, female-fertile mutants (ms1, ms2, ms3, ms4, ms5, ms6, ms7, ms8, ms9, msMOS, and msp) have been identified and some of which have been mapped to soybean chromosomes. The objec...

  13. Analysis of Ethanolamines: Validation of Semi-Volatile Analysis by HPLC-MS/MS by EPA Method MS888

    SciTech Connect

    Owens, J; Vu, A; Koester, C

    2008-10-08

    The Environmental Protection Agency's (EPA) Region 5 Chicago Regional Laboratory (CRL) developed a method titled 'Analysis of Diethanolamine, Triethanolamine, n-Methyldiethanolamine, and n-Ethyldiethanolamine in Water by Single Reaction Monitoring Liquid Chromatography/Tandem Mass Spectrometry (LC/MS/MS): EPA Method MS888'. This draft standard operating procedure (SOP) was distributed to multiple EPA laboratories and to Lawrence Livermore National Laboratory, which was tasked to serve as a reference laboratory for EPA's Environmental Reference Laboratory Network (ERLN) and to develop and validate analytical procedures. The primary objective of this study was to validate and verify the analytical procedures described in 'EPA Method MS888' for analysis of the listed ethanolamines in aqueous samples. The gathered data from this validation study will be used to: (1) demonstrate analytical method performance; (2) generate quality control acceptance criteria; and (3) revise the SOP to provide a validated method that would be available for use during a homeland security event. The data contained in this report will be compiled, by EPA CRL, with data generated by other EPA Regional laboratories so that performance metrics of 'EPA Method MS888' can be determined.

  14. Analysis of Carbamate Pesticides: Validation of Semi-Volatile Analysis by HPLC-MS/MS by EPA Method MS666

    SciTech Connect

    Owens, J; Koester, C

    2008-05-14

    The Environmental Protection Agency's (EPA) Region 5 Chicago Regional Laboratory (CRL) developed a method for analysis of aldicarb, bromadiolone, carbofuran, oxamyl, and methomyl in water by high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS), titled Method EPA MS666. This draft standard operating procedure (SOP) was distributed to multiple EPA laboratories and to Lawrence Livermore National Laboratory, which was tasked to serve as a reference laboratory for EPA's Environmental Reference Laboratory Network (ERLN) and to develop and validate analytical procedures. The primary objective of this study was to validate and verify the analytical procedures described in MS666 for analysis of carbamate pesticides in aqueous samples. The gathered data from this validation study will be used to: (1) demonstrate analytical method performance; (2) generate quality control acceptance criteria; and (3) revise the SOP to provide a validated method that would be available for use during a homeland security event. The data contained in this report will be compiled, by EPA CRL, with data generated by other EPA Regional laboratories so that performance metrics of Method EPA MS666 can be determined.

  15. Improving natural products identification through targeted LC-MS/MS in an untargeted secondary metabolomics workflow.

    PubMed

    Hoffmann, Thomas; Krug, Daniel; Hüttel, Stephan; Müller, Rolf

    2014-11-04

    Tandem mass spectrometry is a widely applied and highly sensitive technique for the discovery and characterization of microbial natural products such as secondary metabolites from myxobacteria. Here, a data mining workflow based on MS/MS precursor lists targeting only signals related to bacterial metabolism is established using LC-MS data of crude extracts from shaking flask fermentations. The devised method is not biased toward specific compound classes or structural features and is capable of increasing the information content of LC-MS/MS analyses by directing fragmentation events to signals of interest. The approach is thus contrary to typical auto-MS(2) setups where precursor ions are usually selected according to signal intensity, which is regarded as a drawback for metabolite discovery applications when samples contain many overlapping signals and the most intense signals do not necessarily represent compounds of interest. In line with this, the method described here achieves improved MS/MS scan coverage for low-abundance precursor ions not captured by auto-MS(2) experiments and thereby facilitates the search for new secondary metabolites in complex biological samples. To underpin the effectiveness of the approach, the identification and structure elucidation of two new myxobacterial secondary metabolite classes is reported.

  16. Electrospray Ionization Tandem Mass Spectrometry (ESI-MS/MS)-Based Shotgun Lipidomics

    SciTech Connect

    Mezengie, Giorgis I.

    2011-01-11

    In the past decade, many new strategies for mass spectrometry (MS)-based analyses of lipids have been developed. Lipidomics is one of the most promising research fields to emerge as a result of these advances in MS. Currently, mass spectrometric analysis of lipids involves two complementary approaches: direct infusion (shotgun lipidomics) and liquid chromatography coupled to MS. In this chapter, I will demonstrate the approach of shotgun lipidomics using electrospray ionization tandem MS for the analysis of lipid molecular species directly from crude biological extracts of tissue or fluids.

  17. Analysis of Combustion Chamber Deposits by ESI-TOF-MS and MALDI-TOF-MS

    SciTech Connect

    Reynolds, J G; Shields, S J; Roos, J W

    2001-06-14

    Combustion chamber deposits (CCDs) in internal combustion engines have been studied by various techniques to understand the relationship of performance degradation with deposit quantity and structure. XPS, XAS, NMR, and elemental analysis have offered insight into the bulk structure of C, H, N, O and metal components [1]. MS has offered some information about compound structure, but results are limited due to the insolubility and complexity of the materials. Recent advances in MS have opened new possibilities for analysis of CCDs. Here we report initial findings on the carbon structure of these deposits determined by ESI-TOF-MS and MADLI-TOF-MS.

  18. Reliable procedures to evaluate and repair crosstalk for bioanalytical MS/MS assays.

    PubMed

    Morin, Louis-Philippe; Mess, Jean-Nicholas; Furtado, Milton; Garofolo, Fabio

    2011-02-01

    Louis-Philippe Morin is a senior instrument application specialist at Algorithme Pharma, a CRO located in Laval, Canada. He has been working in the bioanalysis industry for the past 10 years where he became a subject matter expert in analytical instrumentation, especially in the MS field. His responsibilities in his current position are to optimize the workflow of the laboratory and to find new procedures, or approaches, to fix complex analytical problems. Louis-Philippe's expertise acquired over the years has led him to multiple publications regarding instrumentation. LC-MS/MS is the analytical technique of choice for the quantification of drugs in biological fluids. In recent years, MS/MS detection has been impacted by the rapid evolution of bioanalysis industry requirements. The availability of fast chromatographic systems, the demand for wider dynamic ranges and the extensive use of stable isotope-labeled internal standards in bioanalysis has pushed some triple quadrupole detectors to their limits of operation. Consequently, this situation has led to a re-evaluation of the problem of crosstalk as a potential cause of issues in bioanalysis. In this article, the importance of crosstalk verification on the MS/MS instrument will be demonstrated. Additionally, procedures to identify, evaluate and fix possible crosstalk issues during bioanalytical assays on MS/MS instruments are proposed.

  19. Rugged LC-MS/MS survey analysis for acrylamide in foods.

    PubMed

    Roach, John A G; Andrzejewski, Denis; Gay, Martha L; Nortrup, David; Musser, Steven M

    2003-12-17

    The described liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the detection of acrylamide in food entails aqueous room temperature extraction, SPE cleanup, and analysis by LC-MS/MS. The method is applicable to a wide variety of foods. [(13)C(3)]acrylamide is the internal standard. The limit of quantitation is 10 ppb (microg/kg). Data were obtained in duplicate from >450 products representing >35 different food types. The variability in analyte levels in certain food types suggests that it may be possible to reduce acrylamide levels in those foods.

  20. Metabolic profiling of roots of liquorice (Glycyrrhiza glabra) from different geographical areas by ESI/MS/MS and determination of major metabolites by LC-ESI/MS and LC-ESI/MS/MS.

    PubMed

    Montoro, Paola; Maldini, Mariateresa; Russo, Mariateresa; Postorino, Santo; Piacente, Sonia; Pizza, Cosimo

    2011-02-20

    Liquid chromatography electrospray mass spectrometry (LC-ESI/MS) has been applied to the full characterization of saponins and phenolics in hydroalcoholic extracts of roots of liquorice (Glycyrrhiza glabra). Relative quantitative analyses of the samples with respect to the phenolic constituents and to a group of saponins related to glycyrrhizic acid were performed using LC-ESI/MS. For the saponin constituents, full scan LC-MS/MS fragmentation of the protonated (positive ion mode) or deprotonated (negative ion mode) molecular species generated diagnostic fragment ions that provided information concerning the triterpene skeleton and the number and nature of the substituents. On the basis of the specific fragmentation of glycyrrhizic acid, an LC-MS/MS method was developed in order to quantify the analyte in the liquorice root samples. Chinese G. glabra roots contained the highest levels of glycyrrhizic acid, followed by those from Italy (Calabria).

  1. MS in prose, poems and drama.

    PubMed

    Riem, Philine; Karenberg, Axel

    2015-09-01

    Presentations of MS in fictional literature have not been previously researched. This paper surveys and analyses these portrayals of the disease for the first time. Relevant works in English and German were identified by means of keyword searches in online public access catalogues and search engines as well as old-fashioned research. The neurological and literary evaluation of these 7000 pages of text combines qualitative and quantitative methods. Between 1954 and 2012 at least 55 literary works appeared with an MS motif (35 novels, 18 poems, one novella and one drama). The authors were predominantly female and a third of them suffered from the disease. Patients in the novels largely reflect real epidemiology as regards symptoms and disease progression, while diagnostic and therapeutic options play a secondary role. From a literary point of view, 'entwicklungsromane', 'relationship novels' and 'young adult books' can be discerned. MS is often portrayed in metaphoric language as the enemy: a demon, an animalistic being, prison or an abyss. The MS motif evidences a medicalization of the literature as well as a literary portrayal of anthropological experiences. Well-written novels can contribute to the de-stigmatization of MS and impart basic medical knowledge. © The Author(s), 2015.

  2. Improved Chiral Separation of Methamphetamine Enantiomers Using CSP-LC-MS-MS.

    PubMed

    Ward, Lauren F; Enders, Jeffrey R; Bell, David S; Cramer, Hugh M; Wallace, Frank N; McIntire, Gregory L

    2016-05-01

    To determine the true enantiomeric composition of methamphetamine urine drug testing results, chiral separation of dextro (D) and levo (L) enantiomers is necessary. While enantiomeric separation of methamphetamine has traditionally been accomplished using gas chromatography-mass spectrometry (GC-MS), chiral separation of D- and L-methamphetamine by chiral stationary phase (CSP) liquid chromatography-mass spectrometry/mass spectrometry (LC-MS-MS) has proved more reliable. Chirally selective detection of methamphetamine by GC-MS is often performed using L-N-trifluoroacetyl-prolyl chloride (TPC). L-TPC, a chiral compound, is known to have impurities that can affect the chiral composition percentages of the methamphetamine sample, potentially leading to inaccurate patient results. The comparative analysis of the samples run by GC and LC methods showed preferential bias of the GC method for producing error rates, consistent with previous research, of 8-19%. The CSP-LC-MS-MS method produces percent deviation errors of <2%. Additionally, the GC method failed to produce results that were 100% D- or L-isomer even for enantiomerically pure standards. A higher rate of D- and L-methamphetamine isomer racemization is seen in samples when analyzed by GC-MS using L-TPC-derivatizing agent. This racemization is not seen when these samples are tested with CSP-LC-MS-MS. Thus, a more accurate method of enantiomeric analysis is provided by CSP-LC-MS-MS. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  3. Recommendations for validation of LC-MS/MS bioanalytical methods for protein biotherapeutics.

    PubMed

    Jenkins, Rand; Duggan, Jeffrey X; Aubry, Anne-Françoise; Zeng, Jianing; Lee, Jean W; Cojocaru, Laura; Dufield, Dawn; Garofolo, Fabio; Kaur, Surinder; Schultz, Gary A; Xu, Keyang; Yang, Ziping; Yu, John; Zhang, Yan J; Vazvaei, Faye

    2015-01-01

    This paper represents the consensus views of a cross-section of companies and organizations from the USA and Canada regarding the validation and application of liquid chromatography tandem mass spectrometry (LC-MS/MS) methods for bioanalysis of protein biotherapeutics in regulated studies. It was prepared under the auspices of the AAPS Bioanalytical Focus Group's Protein LC-MS Bioanalysis Subteam and is intended to serve as a guide to drive harmonization of best practices within the bioanalytical community and provide regulators with an overview of current industry thinking on applying LC-MS/MS technology for protein bioanalysis. For simplicity, the scope was limited to the most common current approach in which the protein is indirectly quantified using LC-MS/MS measurement of one or more of its surrogate peptide(s) produced by proteolytic digestion. Within this context, we considered a range of sample preparation approaches from simple in-matrix protein denaturation and digestion to complex procedures involving affinity capture enrichment. Consideration was given to the method validation experiments normally associated with traditional LC-MS/MS and ligand-binding assays. Our collective experience, thus far, is that LC-MS/MS methods for protein bioanalysis require different development and validation considerations than those used for small molecules. The method development and validation plans need to be tailored to the particular assay format being established, taking into account a number of important factors: the intended use of the assay, the test species or study population, the characteristics of the protein biotherapeutic and its similarity to endogenous proteins, potential interferences, as well as the nature, quality, and availability of reference and internal standard materials.

  4. The pinhole interface for IMS/MS

    NASA Technical Reports Server (NTRS)

    Spangler, Glenn E.

    1995-01-01

    An important supplementary technique for ion mobility spectrometry (IMS) is mass spectrometry (MS). A mass spectrometer coupled to an ion mobility spectrometer (IMS/MS) can provide significant information on the composition of the ions contributing to an ion mobility peak. On the other hand, the interpretation of IMS/MS results requires knowledge of processes which can occur at the pinhole interface. When the ion composition is a mixture of ion clusters, the observed cluster distribution may not be an accurate representation of the ion clusters in the IMS. Depending on the buffer gas, lower clusters can form by equilibrating with reduced concentrations in the continuum regime of the expansion and larger clusters can form by collisional stabilization in the cooled jet stream. Besides water, nitrogen molecules can also add to the ion clusters. Even though nitrogen is non-polar, this addition is made possible by an ion-induced dipole interaction between the ion and molecule.

  5. Overlapping MALDI-Mass Spectrometry Imaging for In-Parallel MS and MS/MS Data Acquisition without Sacrificing Spatial Resolution

    NASA Astrophysics Data System (ADS)

    Hansen, Rebecca L.; Lee, Young Jin

    2017-09-01

    Metabolomics experiments require chemical identifications, often through MS/MS analysis. In mass spectrometry imaging (MSI), this necessitates running several serial tissue sections or using a multiplex data acquisition method. We have previously developed a multiplex MSI method to obtain MS and MS/MS data in a single experiment to acquire more chemical information in less data acquisition time. In this method, each raster step is composed of several spiral steps and each spiral step is used for a separate scan event (e.g., MS or MS/MS). One main limitation of this method is the loss of spatial resolution as the number of spiral steps increases, limiting its applicability for high-spatial resolution MSI. In this work, we demonstrate multiplex MS imaging is possible without sacrificing spatial resolution by the use of overlapping spiral steps, instead of spatially separated spiral steps as used in the previous work. Significant amounts of matrix and analytes are still left after multiple spectral acquisitions, especially with nanoparticle matrices, so that high quality MS and MS/MS data can be obtained on virtually the same tissue spot. This method was then applied to visualize metabolites and acquire their MS/MS spectra in maize leaf cross-sections at 10 μm spatial resolution. [Figure not available: see fulltext.

  6. MEASUREMENT OF OXIDATIVE STRESS PARAMETERS USING LIQUID CHROMATOGRAPHY - TANDEM MASS SPECTROSCOPY (LC-MS/MS)

    EPA Science Inventory

    What is the study?
    An invited review article. Measurement of oxidative stress parameters using liquid chromatography-tandem mass spectroscopy (LC-MS/MS)
    Why was it done?
    Although oxidative stress is frequently cited as a cause of various adverse biological eff...

  7. High sensitive and throughput screening of Aflatoxin using MALDI-TOF-TOF-PSD-MS/MS

    USDA-ARS?s Scientific Manuscript database

    We have achieved sensitive and efficient detection of aflatoxin B1(AFB1) through matrix-assisted laser desorption/ionization time-of-flight-time-of-flight mass spectrometry (MALDI-TOF-TOF) and post-source decay (PSD) tandem mass spectrometry (MS/MS) using an acetic acid – a-cyano-4-hydroxycinnamic a...

  8. Software pipeline and data analysis for MS/MS proteomics: the trans-proteomic pipeline.

    PubMed

    Keller, Andrew; Shteynberg, David

    2011-01-01

    The LC-MS/MS shotgun proteomics workflow is widely used to identify and quantify sample peptides and proteins. The technique, however, presents a number of challenges for large-scale use, including the diverse raw data file formats output by mass spectrometers, the large false positive rate among peptide assignments to MS/MS spectra, and the loss of connectivity between identified peptides and the sample proteins that gave rise to them. Here we describe the Trans-Proteomic Pipeline, a freely available open source software suite that provides uniform analysis of LC-MS/MS data from raw data to quantified sample proteins. In a straightforward manner, users can extract MS/MS information from raw data of many instrument formats, submit them to search engines for peptide identification, validate the results to remove false hits, combine together results of multiple search engines, infer sample proteins that gave rise to the identified peptides, and perform quantitation at the peptide and protein levels.

  9. Sample preparation for proteomic analysis using a GeLC-MS/MS strategy.

    PubMed

    Paulo, Joao A

    In-gel digestion coupled with mass spectrometric analysis (GeLC-MS/MS) is a cornerstone for protein identification and characterization. Here I review this versatile approach which combines classical and modern biochemistry strategies and allows for targeted and proteome-wide analyses. Starting with any protein sample, reduced and alkylated proteins are precipitated prior to fractionation by SDS-PAGE. Proteins are in-gel digested and the resulting peptides are extracted and desalted for downstream LC-MS/MS analysis. GeLC-MS/MS leverages the advantages of both traditional SDS-PAGE visualization and protein fractionation with the robust protein and post-translational modification identification and quantitation capabilities of state-of-the-art mass spectrometry-based technology. As such, this strategy allows for the visible assessment of protein amount and quality, prior to analysis via virtually any mass spectrometry platform. Moreover, gel extracted peptides may be derived from any sample type-e.g., from cell culture, tissue, body fluid, or recombinantly-expressed protein-and are fully compatible with isobaric tagging. GeLC-MS/MS is an invaluable technique for proteomic analyses.

  10. A multiclass multiresidue LC-MS/MS method for analysis of veterinary drugs in bovine kidney

    USDA-ARS?s Scientific Manuscript database

    The increased efficiency permitted by multiclass, multiresidue methods has made such approaches very attractive to laboratories involved in monitoring veterinary drug residues in animal tissues. In this current work, evaluation of a multiclass multiresidue LC-MS/MS method in bovine kidney is describ...

  11. MEASUREMENT OF OXIDATIVE STRESS PARAMETERS USING LIQUID CHROMATOGRAPHY - TANDEM MASS SPECTROSCOPY (LC-MS/MS)

    EPA Science Inventory

    What is the study?
    An invited review article. Measurement of oxidative stress parameters using liquid chromatography-tandem mass spectroscopy (LC-MS/MS)
    Why was it done?
    Although oxidative stress is frequently cited as a cause of various adverse biological eff...

  12. Determination of anthelmintic drug residues in milk using UPLC-MS/MS with rapid polarity switching

    USDA-ARS?s Scientific Manuscript database

    A new UPLC-MS/MS (ultra-performance liquid chromatography coupled to tandem mass spectrometry) method was developed and validated to detect 38 anthelmintic drug residues, consisting of benzimidazoles, avermectins and flukicides. A modified QuEChERS-type extraction method was developed with an added...

  13. Natural isotope correction of MS/MS measurements for metabolomics and (13)C fluxomics.

    PubMed

    Niedenführ, Sebastian; ten Pierick, Angela; van Dam, Patricia T N; Suarez-Mendez, Camilo A; Nöh, Katharina; Wahl, S Aljoscha

    2016-05-01

    Fluxomics and metabolomics are crucial tools for metabolic engineering and biomedical analysis to determine the in vivo cellular state. Especially, the application of (13)C isotopes allows comprehensive insights into the functional operation of cellular metabolism. Compared to single MS, tandem mass spectrometry (MS/MS) provides more detailed and accurate measurements of the metabolite enrichment patterns (tandem mass isotopomers), increasing the accuracy of metabolite concentration measurements and metabolic flux estimation. MS-type data from isotope labeling experiments is biased by naturally occurring stable isotopes (C, H, N, O, etc.). In particular, GC-MS(/MS) requires derivatization for the usually non-volatile intracellular metabolites introducing additional natural isotopes leading to measurements that do not directly represent the carbon labeling distribution. To make full use of LC- and GC-MS/MS mass isotopomer measurements, the influence of natural isotopes has to be eliminated (corrected). Our correction approach is analyzed for the two most common applications; (13)C fluxomics and isotope dilution mass spectrometry (IDMS) based metabolomics. Natural isotopes can have an impact on the calculated flux distribution which strongly depends on the substrate labeling and the actual flux distribution. Second, we show that in IDMS based metabolomics natural isotopes lead to underestimated concentrations that can and should be corrected with a nonlinear calibration. Our simulations indicate that the correction for natural abundance in isotope based fluxomics and quantitative metabolomics is essential for correct data interpretation.

  14. MS Allen readies MS Lenoir for Vestibular Study Experiment on middeck

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Mission Specialist (MS) Allen secures MS Lenoir to middeck floor using gaffer's tape. Allen and Lenoir are conducting a biomedical test. Lenoir has electrodes attached to his face for the measuring of his responses to pre-designed activities for evaluation and comparison with responses to the same occurrences in one gravity.

  15. Label-Free Proteome Profiling of Carbapenem-Resistant Klebsiella pneumoniae LC-MS/MS

    DTIC Science & Technology

    2016-12-12

    Title Carbapenem- resistant Klebsiella pneumoniae LC-MS/MS Description A comprehensive analysis of proteome changes in CRKP cells in response to...the sub-MIC doses of antibiotics was performed by using label-free quantitative mass spectrometry. Sample Processing Protocol The pellets were

  16. STS-47 MS Davis and MS Jemison with LBNP device in SLJ module aboard OV-105

    NASA Technical Reports Server (NTRS)

    1992-01-01

    STS-47 Mission Specialist (MS) N. Jan Davis (left) and MS Mae C. Jemison prepare the lower body negative pressure (LBNP) device for the LBNP experiment in the Spacelab Japan (SLJ) science module aboard the Earth-orbiting Endeavour, Orbiter Vehicle (OV) 105. Displayed on the aft end cone in the background is an Auburn University banner.

  17. Gluten Detection and Speciation by Liquid Chromatography Mass Spectrometry (LC-MS/MS)

    PubMed Central

    Lock, Stephen

    2013-01-01

    Liquid chromatography tandem mass spectrometry (LC-MS/MS) has been used historically in proteomics research for over 20 years. However, until recently LC-MS/MS has only been routinely used in food testing for small molecule contaminant detection, for example pesticide and veterinary residue detection, and not as a replacement of microbiological food testing methods, specifically allergen analysis. Over the last couple of years, articles have started to be published which describe the detection of allergens by LC-MS/MS. In this article we will describe how LC-MS/MS can be applied in the area of gluten detection and how it can be used to specifically differentiate the species of gluten used in food, where specific markers for each variety of gluten can be simultaneously acquired and detected at the same time. The article will discuss the effect of variety on the peptide response observed from different wheat grain varieties and will describe the sample preparation protocol which is essential for generating the peptide markers used for speciation. PMID:28234302

  18. STS-48 MS Buchli and MS Gemar on MB SMS middeck during JSC training session

    NASA Technical Reports Server (NTRS)

    1991-01-01

    STS-48 Discovery, Orbiter Vehicle (OV) 103, Mission Specialist (MS) James F. Buchli (left) and MS Charles D. Gemar listen to instructions while on the middeck of JSC's Motion Based (MB) Shuttle Mission Simulator (SMS). Buchli and Gemar are reviewing inflight procedures during this preflight familiarization session held in the Mission Simulation and Training Facility Bldg 5.

  19. STS-44 MS Runco and MS Voss pose with EMUs in OV-104's airlock

    NASA Technical Reports Server (NTRS)

    1991-01-01

    STS-44 Mission Specialist (MS) Mario Runco, Jr (left) and MS James S. Voss pose with two extravehicular mobility units (EMUs) in Atlantis', Orbiter Vehicle (OV) 104's, airlock. The EMUs are mounted on airlock adapter plates (AAPs) and have lower torso restraints in place. They are stowed in the airlock and will be used in the event of a contingency extravehicular activity (EVA).

  20. 12 CFR Appendix Ms-3 to Part 1024 - Appendix MS-3 to Part 1024

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... you buy yourself. If you have any questions, please contact us at . MS-3(B)—Model Form for Force... have any questions, please contact us at . MS-3(C)—Model Form for Force-Placed Insurance Notice... have any questions, please contact us at . Effective Date Notes: 1. At 78 FR 10886, Feb. 14,...

  1. Rapid sample pre-treatment prior to GC-MS and GC-MS/MS urinary toxicological screening.

    PubMed

    Versace, François; Sporkert, Frank; Mangin, Patrice; Staub, Christian

    2012-11-15

    Drug screening is an important issue in clinical and forensic toxicology. Gas chromatography coupled to mass spectrometry (GC-MS) remains the gold standard technique for the screening of unknown compounds in urine samples. However, this technique requires substantial sample preparation, which is time consuming. Moreover, some common drugs such as cannabis cannot be easily detected in urine using general procedures. In this work, a sample preparation protocol for treating 200 μL of urine in less than 30 min is described. The enzymatic hydrolysis of glucuro-conjugates was performed in 5 min thanks to the use of microwaves. The use of a deconvolution software allowed reducing the GC-MS run to 10 min, without impairing the quality of the compound identifications. Comparing the results from 139 authentic urine samples to those obtained using the current routine analysis indicated this method performed well. Moreover, additional 5-min GC-MS/MS programs are described, enabling a very sensitive target screening of 54 drugs, including THC-COOH or buprenorphine, without further sample preparation. These methods appeared as an interesting alternative to immuno-assays based screening. The analytical strategy presented in this article proved to be a promising approach for systematic toxicological analysis (STA) of drugs in urine.

  2. Metabolic fate of the antipsychotic agent, mazapertine, in man--API-MS and MS/MS identification of urinary metabolites.

    PubMed

    Wu, Wu-Nan; McKown, Linda A; Reitz, Allen B

    2007-01-01

    The in vivo metabolism of the antipsychotic agent mazapertine was studied after oral administration of mazapertine succinate (40 mg/subject) to two healthy volunteers, and urine (0-24 hours) was obtained for metabolite identification using API-ionspray LC/MS and MS/MS analysis. Unchanged mazapertine (12% of the sample) plus 10 metabolites were profiled, quantified, and tentatively identified on the basis of MS data, Glusulase-hydrolysis, and by comparison to synthetic samples. The formation of mazapertine metabolites are via seven metabolic pathways: (1) phenylhydroxylation, (2) piperidyl oxidation, (3) O-dealkylation, (4) N-dephenylation, (5) oxidative N-debenzylation, (6). depiperidylation, and (7) glucuronidation. Pathways 1, 2, 5 and 7 formed 4-OH-phenyl-mazapertine (M1, 18%) and 4-OH-piperidyl (M2, 14%)-mazapertine, carboxybenzoylpiperidine (M8, 10%) and its glucuronide (M9, 14%) as four major metabolites. Six moderate and minor metabolites (M3-M7 & M10; each < or =10%) formed via a combination of pathways 1-6. Mazapertine is extensively metabolized in humans.

  3. An impulse-driven liquid-droplet deposition interface for combining LC with MALDI MS and MS/MS.

    PubMed

    Young, J Bryce; Li, Liang

    2006-03-01

    A simple and robust impulse-driven droplet deposition system was developed for off-line liquid chromatography matrix-assisted laser desorption ionization mass spectrometry (LC-MALDI MS). The system uses a solenoid operated with a pulsed voltage power supply to generate impulses that dislodge the hanging droplets from the LC outlet directly to a MALDI plate via a momentum transfer process. There is no contact between the LC outlet and the collection surface. The system is compatible with solvents of varying polarity and viscosity, and accommodates the use of hydrophobic and hydrophilic MALDI matrices. MALDI spots are produced on-line with the separation, and do not require further processing before MS analysis. It is shown that high quality MALDI spectra from 5 fmol of pyro-Glu-fibrinopeptide deposition after LC separation could be obtained using the device, indicating that there was no sample loss in the interface. To demonstrate the analytical performance of the system as a proteome analysis tool, a range of BSA digest concentrations covering about 3 orders of magnitude, from 5 fmol to 1 pmol, were analyzed by LC-MALDI quadrupole time-of-flight MS, yielding 6 and 57% amino acid sequence coverage, respectively. In addition, a complex protein mixture of an E. coli cell extract was tryptically digested and analyzed by LC-MALDI MS, resulting in the detection of a total of 409 unique peptides from 100 fractions of 15-s intervals.

  4. The concept of spectral accuracy for MS.

    PubMed

    Wang, Yongdong; Gu, Ming

    2010-09-01

    Though MS has always appeared to be quite different from spectroscopy to analytical chemists who are familiar with both, a careful examination from historical and theoretical perspectives reveals a striking similarity between the two. With the introduction of spectral accuracy, a companion concept to the better known mass accuracy, new capabilities previously thought unfeasible can now be enabled for MS. (To listen to a podcast about this article, please go to the Analytical Chemistry multimedia page at pubs.acs.org/page/ancham/audio/index.html .).

  5. Screening for Expressed Nonribosomal Peptide Synthetases and Polyketide Synthases Using LC-MS/MS-Based Proteomics

    PubMed Central

    Chen, Yunqiu; McClure, Ryan A.; Kelleher, Neil L.

    2016-01-01

    Liquid chromatography–mass spectrometry (LC-MS)-based proteomics is a powerful technique for the profiling of protein expression in cells in a high-throughput fashion. Herein we report a protocol using LC-MS/MS-based proteomics for the screening of enzymes involved in natural product biosynthesis, such as nonribosomal peptide synthetases (NRPSs) and polyketide synthases (PKSs) from bacterial strains. Taking advantage of the large size of modular NRPSs and PKSs (often >200 kDa), size-based separation (SDS-PAGE) is employed prior to LC-MS/MS analysis. Based upon the protein identifications obtained through software search, we can accurately pinpoint the expressed NRPS and/or PKS gene clusters from a given strain and growth condition. The proteomics screening result can be used to guide the discovery of potentially new nonribosomal peptide and polyketide natural products. PMID:26831706

  6. MS/MS similarity networking accelerated target profiling of triterpene saponins in Eleutherococcus senticosus leaves.

    PubMed

    Ge, Yue-Wei; Zhu, Shu; Yoshimatsu, Kayo; Komatsu, Katsuko

    2017-07-15

    The targeted mass information of compounds accelerated their discovery in a large volume of untargeted MS data. An MS/MS similarity networking is advanced in clustering the structural analogues, which benefits the collection of mass information of similar compounds. The triterpene saponins extracted from Eleutherococcus senticosus leaves (ESL), a kind of functional tea, have shown promise in the relief of Alzheimer's disease. In this work, a target-precursor list (TPL) generated using MS/MS similarity networking was employed to rapidly trace 106 triterpene saponins from the aqueous extracts of ESL, of which 49 were tentatively identified as potentially new triterpene saponins. Moreover, a compound database of triterpene saponins was established and successfully applied to uncover their distribution features in ESL samples collected from different areas. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Metabolomics and Trace Element Analysis of Camel Tear by GC-MS and ICP-MS.

    PubMed

    Ahamad, Syed Rizwan; Raish, Mohammad; Yaqoob, Syed Hilal; Khan, Altaf; Shakeel, Faiyaz

    2017-06-01

    Camel tear metabolomics and elemental analysis are useful in getting the information regarding the components responsible for maintaining the protective system that allows living in the desert and dry regions. The aim of this study was to correlate that the camel tears can be used as artificial tears for the evaluation of dryness in the eye. Eye biomarkers of camel tears were analyzed by gas chromatography-mass spectroscopy (GC-MS) and inductively coupled plasma mass spectroscopy (ICP-MS). The major compounds detected in camel tears by GC-MS were alanine, valine, leucine, norvaline, glycine, cadaverine, urea, ribitol, sugars, and higher fatty acids like octadecanoic acid and hexadecanoic acid. GC-MS analysis of camel tears also finds several products of metabolites and its associated metabolic participants. ICP-MS analysis showed the presence of different concentration of elemental composition in the camel tears.

  8. Matrix effect elimination during LC-MS/MS bioanalytical method development.

    PubMed

    Côté, Cynthia; Bergeron, Annik; Mess, Jean-Nicholas; Furtado, Milton; Garofolo, Fabio

    2009-10-01

    Due to the presence of endogenous components in biofluids, ionization suppression or enhancement may occur for bioanalytical assays using LC-MS or LC-MS/MS technologies. The matrix effect may affect the precision and accuracy of a bioanalytical method and, therefore, compromise the quality of the results. Protein precipitation sample preparation along with LC-MS/MS is a high-throughput method most commonly used in bioanalysis and is largely affected by the matrix effect. In order to eliminate the matrix effect during the method development, some considerations may be used: cleaner sample preparations, more sensitive instruments, which allow less material to be injected, different chromatographic separations and much more must be investigated. More than giving tools to adequately assess the matrix effect during the method development, this review gives scientists numerous ways to eliminate or reduce the matrix effect based on novel sample-preparation techniques, new chromatographic optimization methods and new technologies.

  9. Determination of steroidal glycosides in Yucca gloriosa flowers by LC/MS/MS.

    PubMed

    Montoro, Paola; Skhirtladze, Alexandre; Perrone, Angela; Benidze, Mariam; Kemertelidze, Ether; Piacente, Sonia

    2010-09-05

    An high-performance liquid chromatography (HPLC) coupled with tandem mass spectrometry (MS/MS) method, was developed for the quantitative analysis of the steroidal glycosides occurring in Yucca gloriosa flowers. The HPLC experiments were performed by means of an octadecyl-modified reversed-phase C-18 column and a binary mobile phase system under gradient elution conditions. The fragmentation patterns of steroidal saponins were analyzed by ESI-MS(n) in positive ion mode and a specific multiple reaction monitoring MS/MS detection was developed for their quantitative determination. The described method provides high sensitivity and specificity for quantitative determination of the steroidal glycosides in Y. gloriosa flowers. Quantification was performed against an external calibration line obtained using each pure steroidal glycoside. Short- and long-term repeatabilities of the methods were better than 3 and 6%, respectively. The method was validated according to EMEA guidelines and applied to real samples.

  10. EMS in Mauritius.

    PubMed

    Ramalanjaona, Georges; Brogan, Gerald X

    2009-02-01

    Mauritius lies in the southwest Indian Ocean about 1250 miles from the African coast and 500 miles from Madagascar. Mauritius (estimated population 1,230,602) became independent from the United Kingdom in 1968 and has one of the highest GDP per capita in Africa. Within Mauritius there is a well established EMS system with a single 999 national dispatch system. Ambulances are either publicly or privately owned. Public ambulances are run by the Government (SAMU). Megacare is a private subscriber only ambulance service. The Government has recently invested in new technology such as telemedicine to further enhance the role of EMS on the island. This article describes the current state of EMS in Mauritius and depicts its development in the context of Government effort to decentralise and modernise the healthcare system.

  11. EMS -- Error Message Service

    NASA Astrophysics Data System (ADS)

    Rees, P. C. T.; Chipperfield, A. J.; Draper, P. W.

    This document describes the Error Message Service, EMS, and its use in system software. The purpose of EMS is to provide facilities for constructing and storing error messages for future delivery to the user -- usually via the Starlink Error Reporting System, ERR (see SUN/104). EMS can be regarded as a simplified version of ERR without the binding to any software environment (e.g., for message output or access to the parameter and data systems). The routines in this library conform to the error reporting conventions described in SUN/104. A knowledge of these conventions, and of the ADAM system (see SG/4), is assumed in what follows. This document is intended for Starlink systems programmers and can safely be ignored by applications programmers and users.

  12. A emissão em 8mm e as bandas de Merrill-Sanford em estrelas carbonadas

    NASA Astrophysics Data System (ADS)

    de Mello, A. B.; Lorenz-Martins, S.

    2003-08-01

    Estrelas carbonadas possuem bandas moleculares em absorção no visível e, no infravermelho (IR) as principais características espectrais se devem a emissão de grãos. Recentemente foi detectada a presença de bandas de SiC2 (Merrill-Sanford, MS) em emissão sendo atribuída à presença de um disco rico em poeira. Neste trabalho analisamos uma amostra de 14 estrelas carbonadas, observadas no telescópio de 1.52 m do ESO em 4 regiões espectrais diferentes, a fim de detectar as bandas de MS em emissão. Nossa amostra é composta de estrelas que apresentam além da emissão em 11.3 mm, outra em 8 mm. Esta última emissão, não usual nestes objetos, tem sido atribuída ou a moléculas de C2H2, ou a um composto sólido ainda indefinido. A detecção de emissões de MS e aquelas no IR, simultaneamente, revelaria um cenário mais complexo que o habitualmente esperado para os ventos destes objetos. No entanto como primeiro resultado, verificamos que as bandas de Merrill-Sanford encontram-se em absorção, não revelando nenhuma conexão com a emissão a 8 mm. Assim, temos duas hipóteses: (a) a emissão a 8 mm se deve à molécula C2H2 ou (b) essa emissão é resultado da emissão térmica de grãos. Testamos a segunda hipótese modelando a amostra com grãos não-homogêneos de SiC e quartzo, o qual emite em aproximadamente 8mm. Este grão seria produzido em uma fase evolutiva anterior a das carbonadas (estrelas S) e por terem uma estrutura cristalina são destruídos apenas na presença de campos de radiação ultravioleta muito intensos. Os modelos para os envoltórios utilizam o método de Monte Carlo para descrever o problema do transporte da radiação. As conclusões deste trabalho são: (1) as bandas de Merrill-Sanford se encontram em absorção, sugerindo um cenário usual para os ventos das estrelas da amostra; (2) neste cenário, a emissão em 8 mm seria resultado de grãos de quartzo com mantos de SiC, indicando que o quartzo poderia sobreviver a fase

  13. Instrument-independent software tools for the analysis of MS-MS and LC-MS lipidomics data.

    PubMed

    Haimi, Perttu; Chaithanya, Krishna; Kainu, Ville; Hermansson, Martin; Somerharju, Pentti

    2009-01-01

    Mass spectrometry (MS), particularly electrospray-MS, is the key tool in modern lipidomics. However, as even a modest scale experiment produces a great amount of data, data processing often becomes limiting. Notably, the software provided with MS instruments are not well suited for quantitative analysis of lipidomes because of the great variety of species present and complexities in response calibration. Here we describe the use of two recently introduced software tools: lipid mass spectrum analysis (LIMSA) and spectrum extraction from chromatographic data (SECD), which significantly increase the speed and reliability of mass spectrometric analysis of complex lipidomes. LIMSA is a Microsoft Excel add-on that (1) finds and integrates the peaks in an imported spectrum, (2) identifies the peaks, (3) corrects the peak areas for overlap by isotopic peaks of other species and (4) quantifies the identified species using included internal standards. LIMSA is instrument-independent because it processes text-format MS spectra. Typically, the analysis of one spectrum takes only a few seconds.The SECD software allows one to display MS chromatograms as two-dimensional maps, which is useful for visual inspection of the data. More importantly, however, SECD allows one to extract mass spectra from user-defined regions of the map for further analysis with, e.g., LIMSA. The use of select regions rather than simple time-range averaging significantly improves the signal-to-noise ratio as signals outside the region of interest are more efficiently excluded. LIMSA and SECD have proven to be robust and convenient tools and are available free of charge from the authors.

  14. Dopamine, T cells and multiple sclerosis (MS).

    PubMed

    Levite, Mia; Marino, Franca; Cosentino, Marco

    2017-03-10

    Dopamine is a key neurotransmitter that induces critical effects in the nervous system and in many peripheral organs, via 5 dopamine receptors (DRs): D1R-D5R. Dopamine also induces many direct and very potent effects on many DR-expressing immune cells, primarily T cells and dendritic cells. In this review, we focus only on dopamine receptors, effects and production in T cells. Dopamine by itself (at an optimal concentration of~0.1 nM) induces multiple function of resting normal human T cells, among them: T cell adhesion, chemotactic migration, homing, cytokine secretion and others. Interestingly, dopamine activates resting effector T cells (Teffs), but suppresses regulatory T cells (Tregs), and both effects lead eventually to Teff activation. Dopamine-induced effects on T cells are dynamic, context-sensitive and determined by the: T cell activation state, T cell type, DR type, and dopamine concentration. Dopamine itself, and also few dopaminergic molecules/ drugs that are in clinical use for cardiac, neurological and other non-immune indications, have direct effects on human T cells (summarized in this review). These dopaminergic drugs include: dopamine = intropin, L-DOPA, bromocriptine, pramipexole, pergolide, haloperidol, pimozide, and amantadine. Other dopaminergic drugs were not yet tested for their direct effects on T cells. Extensive evidence in multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE) show dopaminergic dysregulations in T cells in these diseases: D1-like DRs are decreased in Teffs of MS patients, and dopamine does not affect these cells. In contrast, D1-like DRs are increased in Tregs of MS patients, possibly causing functional Treg impairment in MS. Treatment of MS patients with interferon β (IFN-β) increases D1-like DRs and decreases D2-like DRs in Teffs, decreases D1-like DRs in Tregs, and most important: restores responsiveness of patient's Teffs to dopamine. DR agonists and antagonists confer some benefits in

  15. National EMS Research Agenda.

    PubMed

    Sayre, M R; White, L J; Brown, L H; McHenry, S D

    2002-01-01

    Now, more than ever before, the spirit of the emergency services professional is recognized by people everywhere. Individuals from every walk of life comprehend the reality of the job these professionals do each day. Placing the safety of others above their own is their acknowledged responsibility. Rescue and treatment of ill and injured patients are their purpose as well as their gratification. The men and women who provide prehospital care are well aware of the unpredictable nature of emergency medical services (EMS). Prehospital care is given when and where it is needed: in urban settings with vertical challenges and gridlock; in rural settings with limited access; in confined spaces; within entrapments; or simply in the street, exposed to the elements. Despite the challenges, EMS professionals rise to the occasion to do their best with the resources available. Despite more than 30 years of dedicated service by thousands of EMS professionals, academic researchers, and public policy makers, the nation's EMS system is treating victims of illness and injury with little or no evidence that the care they provide is optimal. A national investment in the EMS research infrastructure is necessary to overcome obstacles currently impeding the accumulation of essential evidence of the effectiveness of EMS practice. Funding is required to train new researchers and to help them establish their careers. Financial backing is needed to support the development of effective prehospital treatments for the diseases that drive the design of the EMS system, including injury and sudden cardiac arrest. Innovative strategies to make EMS research easier to accomplish in emergency situations must be implemented. Researchers must have access to patient outcome information in order to evaluate and improve prehospital care. New biomedical and technical advances must be evaluated using scientific methodology. Research is the key to maintaining focus on improving the overall health of the

  16. 78 FR 25336 - Mississippi Disaster # MS-00066

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-30

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION Mississippi Disaster MS-00066 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY... Application Deadline Date: 01/21/2014. ADDRESSES: Submit completed loan applications to: U.S. Small...

  17. Polymer Characterization Using TG-MS Techniques

    DTIC Science & Technology

    1977-04-01

    Patterson Air Force Base, Ohio 45433 SYNOPSIS Thermal degradation of a series of 2,5 perfluoroalkyl - and perfluoroalkyl ether-substituted...elastomeric properties, have been studied using TG-MS. These are all 2,5 perfluoroalkyl - and perfluoroalkyl ether-substituted bibenzoxazoles. We...flexibility of perfluoroalkyl ether chains can provide enhanced elastomerlc properties. There Is a wide range of perfluoroalkyl

  18. Ms. Affirmation and Her Technicolor Responses.

    ERIC Educational Resources Information Center

    Johnson-Kuby, Sue Ann; Katz, Claudia Anne

    1997-01-01

    Presents four questions from teachers regarding "classroom dilemmas" (such as seating assignments, requests for bathroom visits, and parent/teacher communication) with the responses by "Ms. Affirmation," a middle-school guidance counselor who collaborates with teachers to assist them in working with students. (SR)

  19. Familiar Face Detection in 180 ms.

    PubMed

    Visconti di Oleggio Castello, Matteo; Gobbini, M Ida

    2015-01-01

    The visual system is tuned for rapid detection of faces, with the fastest choice saccade to a face at 100 ms. Familiar faces have a more robust representation than do unfamiliar faces, and are detected faster in the absence of awareness and with reduced attentional resources. Faces of family and close friends become familiar over a protracted period involving learning the unique visual appearance, including a view-invariant representation, as well as person knowledge. We investigated the effect of personal familiarity on the earliest stages of face processing by using a saccadic-choice task to measure how fast familiar face detection can happen. Subjects made correct and reliable saccades to familiar faces when unfamiliar faces were distractors at 180 ms--very rapid saccades that are 30 to 70 ms earlier than the earliest evoked potential modulated by familiarity. By contrast, accuracy of saccades to unfamiliar faces with familiar faces as distractors did not exceed chance. Saccades to faces with object distractors were even faster (110 to 120 ms) and equivalent for familiar and unfamiliar faces, indicating that familiarity does not affect ultra-rapid saccades. We propose that detectors of diagnostic facial features for familiar faces develop in visual cortices through learning and allow rapid detection that precedes explicit recognition of identity.

  20. MS Musgrave conducts CFES experiment on middeck

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Mission Specialist (MS) Musgrave readies biological sample plate for insertion into Continuous Flow Electrophoresis System (CFES) fluid systems opens biological sample compartment on fluid systems module and documents experiment progress at separation column with 35mm camera. CFES is located on middeck in the galley position (port side wall) with control panel ML86B and water dispenser appearing on the right.

  1. 78 FR 3494 - Mississippi Disaster #MS-00063

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-16

    ... ADMINISTRATION Mississippi Disaster MS-00063 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY: This is a notice of an Administrative declaration of a disaster for the State of Mississippi dated 01... adversely affected by the disaster: Primary Counties: Pearl River. Contiguous Counties: Mississippi;...

  2. 76 FR 28120 - Mississippi Disaster #MS-00047

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-13

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION Mississippi Disaster MS-00047 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY... State of Mississippi (FEMA- 1972-DR), dated 04/29/2011. Incident: Severe Storms, Tornadoes,...

  3. 75 FR 25305 - Mississippi Disaster #MS-00036

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-07

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION Mississippi Disaster MS-00036 AGENCY: Small Business Administration. ACTION: Notice. SUMMARY: This... State of Mississippi (FEMA- 1906-DR), dated 04/29/2010. Incident: Severe Storms, Tornadoes, and...

  4. 78 FR 13393 - Mississippi Disaster # MS-00065

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-27

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION Mississippi Disaster MS-00065 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY... State of Mississippi (FEMA- 4101-DR), dated 02/19/2013. Incident: Severe Storms, Tornadoes, and...

  5. 77 FR 55890 - Mississippi Disaster # MS-00059

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-11

    ... ADMINISTRATION Mississippi Disaster MS-00059 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY: This is a Notice of the Presidential declaration of a major disaster for the State of Mississippi (FEMA... Only): Mississippi: Forrest, George, Lamar, Marion, Stone. Alabama: Mobile. Louisiana: Saint...

  6. 76 FR 43368 - Mississippi Disaster #MS-00049

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-20

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION Mississippi Disaster MS-00049 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY... State of Mississippi (FEMA- 1983-DR), dated 07/12/2011. Incident: Flooding. Incident Period:...

  7. 75 FR 79064 - Mississippi Disaster #MS-00042

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-17

    ... ADMINISTRATION Mississippi Disaster MS-00042 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY: This is a notice of an Administrative declaration of a disaster for the State of Mississippi dated 12...: Mississippi: Chickasaw, Choctaw, Clay, Itawamba, Lee, Lowndes, Noxubee, Webster, Winston. Alabama:...

  8. 75 FR 29371 - Mississippi Disaster #MS-00037

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-25

    ... ADMINISTRATION Mississippi Disaster MS-00037 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY: This is a Notice of the Presidential declaration of a major disaster for the State of Mississippi (FEMA..., Lafayette, Tippah, Tishomingo. Contiguous Counties (Economic Injury Loans Only): Mississippi:...

  9. 76 FR 29810 - Mississippi Disaster #MS-00048

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-23

    ... ADMINISTRATION Mississippi Disaster MS-00048 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY: This is a Notice of the Presidential declaration of a major disaster for the State of Mississippi (FEMA...): Mississippi: Amite, Attala, Copiah, Franklin, Hinds, Holmes, Leflore, Lincoln, Madison, Marshall,...

  10. 76 FR 27139 - Mississippi Disaster # MS-00045

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-10

    ... ADMINISTRATION Mississippi Disaster MS-00045 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY: This is a Notice of the Presidential declaration of a major disaster for the State of Mississippi (FEMA...): Mississippi Calhoun, Chickasaw, Claiborne, Clay, Copiah, George, Itawamba, Jones, Lauderdale, Lee,...

  11. 78 FR 12805 - Mississippi Disaster #MS-00064

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-25

    ... ADMINISTRATION Mississippi Disaster MS-00064 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY: This is a Notice of the Presidential declaration of a major disaster for the State of Mississippi (FEMA... (Economic Injury Loans Only): Mississippi: Covington, Jefferson Davis, Jones, Marion, Pearl River,...

  12. 75 FR 29370 - Mississippi Disaster #MS-00039

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-05-25

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION Mississippi Disaster MS-00039 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY... State of Mississippi (FEMA- 1916-DR), dated 05/14/2010. Incident: Severe Storms, Tornadoes, and...

  13. Ms. Affirmation and Her Technicolor Responses.

    ERIC Educational Resources Information Center

    Johnson-Kuby, Sue Ann; Katz, Claudia Anne

    1997-01-01

    Presents four questions from teachers regarding "classroom dilemmas" (such as seating assignments, requests for bathroom visits, and parent/teacher communication) with the responses by "Ms. Affirmation," a middle-school guidance counselor who collaborates with teachers to assist them in working with students. (SR)

  14. Endocrine system dynamics and MS epidemiology.

    PubMed

    Moynihan, James; Moore, Helena

    2010-05-01

    In the kidney there is a co-transport relationship in the nephron between the reabsorption of positive Na(+) ions and the reabsorption of negative ions such as uric acid anions. Uric acid acts as an anti-oxidant and it has been shown to have a sealing effect on the blood-brain barrier. The theory developed here is that chronic neurological vasoconstriction in cool environmental conditions injects an offset into the rennin-angiotensin-aldosterone system (RAAS) blood pressure control loop and reduces demand for angiotensin and aldosterone. (Aldosterone is produced in the adrenal gland and has a direct effect on renal reabsorption of Na(+) ions.) Via co-transport these conditions will reduce the body's ability to reabsorb uric acid and this in turn will weaken the integrity of the blood-brain barrier. Also, in cool environments, where levels of vasopressin (ADH) and aldosterone are lower, the gain of the hypothalamus-pituitary-adrenal gland (HPA) axis is reduced so that the production average levels of ACTH, cortisone and aldosterone will be biased at a lower level and the kidney-local levels of aldosterone in particular will remain lower. This paper develops these ideas and suggests that they can help explain the traditionally-recognized latitudinal gradient in MS epidemiology. Also, acclimatization to heat encourages sweating, which should create a greater demand for the renal reabsorption of Na(+) ions which enables greater reabsorption of uric acid. Therefore people living at low latitudes should have a lower chance of hypouricemia and a lower chance of developing MS. In fact people who spend their first fifteen years in the tropics almost never go onto develop MS. And MS patients in relapse are consistently hypouricemic. This hypothesis can explain both of these facts. The paper goes onto show how the MS condition will tend to progress because of a number of self-sustaining effects: over time the immune system becomes more targeted to myelin, MS patients are

  15. Liquid chromatography electron capture dissociation tandem mass spectrometry (LC-ECD-MS/MS) versus liquid chromatography collision-induced dissociation tandem mass spectrometry (LC-CID-MS/MS) for the identification of proteins.

    PubMed

    Creese, Andrew J; Cooper, Helen J

    2007-05-01

    Electron capture dissociation (ECD) offers many advantages over the more traditional fragmentation techniques for the analysis of peptides and proteins, although the question remains: How suitable is ECD for incorporation within proteomic strategies for the identification of proteins? Here, we compare LC-ECD-MS/MS and LC-CID-MS/MS as techniques for the identification of proteins. Experiments were performed on a hybrid linear ion trap-Fourier transform ion cyclotron resonance mass spectrometer. Replicate analyses of a six-protein (bovine serum albumin, apo-transferrin, lysozyme, cytochrome c, alcohol dehydrogenase, and beta-galactosidase) tryptic digest were performed and the results analyzed on the basis of overall protein sequence coverage and sequence tag lengths within individual peptides. The results show that although protein coverage was lower for LC-ECD-MS/MS than for LC-CID-MS/MS, LC-ECD-MS/MS resulted in longer peptide sequence tags, providing greater confidence in protein assignment.

  16. Positional isomer differentiation of synthetic cannabinoid JWH-081 by GC-MS/MS.

    PubMed

    Kusano, Maiko; Zaitsu, Kei; Nakayama, Hiroshi; Nakajima, Junichi; Hisatsune, Kazuaki; Moriyasu, Takako; Matsuta, Shuntaro; Katagi, Munehiro; Tsuchihashi, Hitoshi; Ishii, Akira

    2015-03-01

    Like many new designer drugs of abuse, synthetic cannabinoids (SC) have structural or positional isomers which may or may not all be regulated under law. Differences in acute toxicity may exist between isomers which impose further burden in the fields of forensic toxicology, medicine and legislation. Isomer differentiation therefore becomes crucial from these standpoints as new designer drugs continuously emerge with just minor positional modifications to their preexisting analogs. The aim of this study was to differentiate the positional isomers of JWH-081. Purchased standard compounds of JWH-081 and its positional isomers were analyzed by gas chromatography-electron ionization-mass spectrometry (GC-EI-MS) first in scan mode to investigate those isomers who could be differentiated by EI scan spectra. Isomers with identical or near-identical EI spectra were further subjected to GC-tandem mass spectrometry (MS/MS) analysis with appropriate precursor ions. EI scan was able to distinguish 3 of the 7 isomers: 2-methoxy, 7-methoxy and 8-methoxy. The remaining isomers exhibited near-identical spectra; hence, MS/MS was performed by selecting m/z 185 and 157 as precursor ions. 3-Methoxy and 5-methoxy isomers produced characteristic product ions that enabled the differentiation between them. Product ion spectrum of 6-methoxy isomer resembled that of JWH-081; however, the relative ion intensities were clearly different from one another. The combination of EI scan and MS/MS allowed for the regioisomeric differentiation of the targeted compounds in this study.

  17. Quantitative determination of paralytic shellfish toxins in cultured toxic algae by LC-MS/MS.

    PubMed

    Watanabe, Ryuichi; Matsushima, Ryoji; Harada, Tomoko; Oikawa, Hiroshi; Murata, Masakazu; Suzuki, Toshiyuki

    2013-01-01

    We developed a sample preparation and LC-MS/MS method for the determination of saxitoxins in toxic algae. Paralytic shellfish toxins (PSTs) were successfully separated by gradient elution on an amide column with the hydrophilic interaction mode and quantified with multiple reaction monitoring (MRM) detection in the positive ion mode. This method showed good performance in the summed LODs and LOQs for all 12 toxins, 25 and 84 nM, respectively. Next, extracts of cultured strains of a toxic dinoflagellate Alexandrium tamarense and a freshwater cyanobacteria Anabaena circinalis were treated in a short column of basic alumina and the toxic fractions were analysed by our LC-MS/MS method and by HPLC with fluorescence detection. Comparison of the results obtained by the two methods demonstrated that approximately equivalent results were obtained for both the dinoflagellate and the cyanobacteria. In addition, the retention time of the toxins showed acceptable shifts. Therefore, the clean-up of the toxic algal extracts by using the basic alumina column controlled unwanted chromatographic behaviour and variable ionisation efficiency during MS detection. LC-MS/MS for saxitoxins has great potential as a rapid analytical method for determining all primary saxitoxins in cultured algae.

  18. LC-MS/MS for protein and peptide quantification in clinical chemistry.

    PubMed

    Rauh, Manfred

    2012-02-01

    The LC-triple quadrupole mass spectrometer (LC-MS/MS) is an increasingly common tool in the clinical laboratory. Established applications include routine assays for detecting inborn errors of metabolism, and for monitoring therapeutic drugs and steroids. Peptides and proteins in biological matrices have traditionally been quantified by immunological methods such as RIA or ELISA. These methods have the drawback of being insufficiently selective, often not allowing differentiation between the peptide and its derivatives or degradation fragments. The improved robustness and sensitivity of LC-MS-based techniques provide reliable alternatives for peptide quantification. Mass spectrometry does not require specific antibody reagents and is a powerful tool for the study of posttranslational modifications (PTM). In addition, several studies have demonstrated the utility of selected reaction monitoring (SRM) assays using stable-isotope-labelled (tryptic) peptides for quantifying proteins in human serum. Peptide-based MS/MS is a relatively new development in the measurement of clinically significant proteins, offering cost effectiveness, high throughput, multiplexed analysis and quantification, with the potential for combining the measurement of small molecules, peptides and proteins on a single technology platform. Quantitative analysis of proteins and peptides by LC-MS/MS is becoming a practical technique for clinical laboratories. To move from the laboratories of highly skilled analysts to routine clinical diagnostic laboratories requires that a number of technical hurdles be overcome in regard to sensitivity, imprecision, accuracy and the sample handling necessary for clinical use.

  19. Retinoid quantification by HPLC/MS(n)

    NASA Technical Reports Server (NTRS)

    McCaffery, Peter; Evans, James; Koul, Omanand; Volpert, Amy; Reid, Kevin; Ullman, M. David

    2002-01-01

    Retinoic acid (RA) mediates most of the biological effects of vitamin A that are essential for vertebrate survival. It acts through binding to receptors that belong to the nuclear receptor transcription factor superfamily (Mangelsdorf et al. 1994). It is also a highly potent vertebrate teratogen. To determine the function and effects of endogenous and exogenous RA, it is important to have a highly specific, sensitive, accurate, and precise analytical procedure. Current analyses of RA and other retinoids are labor intensive, of poor sensitivity, have limited specificity, or require compatibility with RA reporter cell lines (Chen et al. 1995. BIOCHEM: Pharmacol. 50: 1257-1264; Creech Kraft et al. 1994. BIOCHEM: J. 301: 111-119; Lanvers et al. 1996. J. Chromatogr. B Biomed. Appl. 685: 233-240; Maden et al. 1998. DEVELOPMENT: 125: 4133-4144; Wagner et al. 1992. DEVELOPMENT: 116: 55-66). This paper describes an HPLC/mass spectrometry/mass spectrometry product ion scan (HPLC/MS(n)) procedure for the analysis of retinoids that employs atmospheric pressure chemical ionization MS. The retinoids are separated by normal-phase column chromatography with a linear hexane-isopropanol-dioxane gradient. Each retinoid is detected by a unique series of MS(n) functions set at optimal collision-induced dissociation energy (30% to 32%) for all MS(n) steps. The scan events are divided into three segments, based on HPLC elution order, to maximize the mass spectrometer duty cycle. The all-trans, 9-cis, and 13-cis RA isomers are separated, if desired, by an isocratic hexane-dioxane-isopropanol mobile phase. This paper describes an HPLC/MS(n) procedure possessing high sensitivity and specificity for retinoids.

  20. Retinoid quantification by HPLC/MS(n)

    NASA Technical Reports Server (NTRS)

    McCaffery, Peter; Evans, James; Koul, Omanand; Volpert, Amy; Reid, Kevin; Ullman, M. David

    2002-01-01

    Retinoic acid (RA) mediates most of the biological effects of vitamin A that are essential for vertebrate survival. It acts through binding to receptors that belong to the nuclear receptor transcription factor superfamily (Mangelsdorf et al. 1994). It is also a highly potent vertebrate teratogen. To determine the function and effects of endogenous and exogenous RA, it is important to have a highly specific, sensitive, accurate, and precise analytical procedure. Current analyses of RA and other retinoids are labor intensive, of poor sensitivity, have limited specificity, or require compatibility with RA reporter cell lines (Chen et al. 1995. BIOCHEM: Pharmacol. 50: 1257-1264; Creech Kraft et al. 1994. BIOCHEM: J. 301: 111-119; Lanvers et al. 1996. J. Chromatogr. B Biomed. Appl. 685: 233-240; Maden et al. 1998. DEVELOPMENT: 125: 4133-4144; Wagner et al. 1992. DEVELOPMENT: 116: 55-66). This paper describes an HPLC/mass spectrometry/mass spectrometry product ion scan (HPLC/MS(n)) procedure for the analysis of retinoids that employs atmospheric pressure chemical ionization MS. The retinoids are separated by normal-phase column chromatography with a linear hexane-isopropanol-dioxane gradient. Each retinoid is detected by a unique series of MS(n) functions set at optimal collision-induced dissociation energy (30% to 32%) for all MS(n) steps. The scan events are divided into three segments, based on HPLC elution order, to maximize the mass spectrometer duty cycle. The all-trans, 9-cis, and 13-cis RA isomers are separated, if desired, by an isocratic hexane-dioxane-isopropanol mobile phase. This paper describes an HPLC/MS(n) procedure possessing high sensitivity and specificity for retinoids.

  1. Gaussian and linear deconvolution of LC-MS/MS chromatograms of the eight aminobutyric acid isomers.

    PubMed

    Vemula, Harika; Kitase, Yukiko; Ayon, Navid J; Bonewald, Lynda; Gutheil, William G

    2017-01-01

    Isomeric molecules present a challenge for analytical resolution and quantification, even with MS-based detection. The eight aminobutyric acid (ABA) isomers are of interest for their various biological activities, particularly γ-aminobutyric acid (GABA) and the d- and l-isomers of β-aminoisobutyric acid (β-AIBA; BAIBA). This study aimed to investigate LC-MS/MS-based resolution of these ABA isomers as their Marfey's (Mar) reagent derivatives. HPLC was able to separate three Mar-ABA isomers l-β-ABA (l-BABA), and l- and d-α-ABA (AABA) completely, with three isomers (GABA, and d/l-BAIBA) in one chromatographic cluster, and two isomers (α-AIBA (AAIBA) and d-BABA) in a second cluster. Partially separated cluster components were deconvoluted using Gaussian peak fitting except for GABA and d-BAIBA. MS/MS detection of Marfey's derivatized ABA isomers provided six MS/MS fragments, with substantially different intensity profiles between structural isomers. This allowed linear deconvolution of ABA isomer peaks. Combining HPLC separation with linear and Gaussian deconvolution allowed resolution of all eight ABA isomers. Application to human serum found a substantial level of l-AABA (13 μM), an intermediate level of l-BAIBA (0.8 μM), and low but detectable levels (<0.2 μM) of GABA, l-BABA, AAIBA, d-BAIBA, and d-AABA. This approach should be useful for LC-MS/MS deconvolution of other challenging groups of isomeric molecules.

  2. New approach to study of spilled crude oils using high resolution GC-MS (SIM) and metastable reaction monitoring GC-MS-MS.

    PubMed

    Munoz, D; Doumenq, P; Guiliano, M; Jacquot, F; Scherrer, P; Mille, G

    1997-12-12

    Polycyclic aromatic hydrocarbons (PAHs) and geochemical biomarkers are good environmental markers to study the origin and evolution of an oil spill. To have access to the greatest number of molecular ratios, no fractionation of oil into aliphatic and aromatic compounds is made. Three analytical MS approaches are tested to analyze markers in this total hydrocarbon fraction: classical quadrupole GC-MS, high resolution GC-MS (HR GC-MS) and metastable reaction monitoring GC-MS-MS (MRM GC-MS-MS). This analytical approach is used to follow the evolution of PAHs in petroleum polluted mangrove soils over 8 years by using molecular ratios between polycyclic aromatic hydrocarbons and tri- and tetracyclic terpanes.

  3. Identification of a Bacteria Using Phylogenetic Relationships Revealed by MS/MS Sequencing of Tryptic Peptides Derived From Cellular Proteins

    DTIC Science & Technology

    2004-12-01

    phylogenetic relationships between bacterial species as a part of a hierarchical decision tree process. 1. INTRODUCTION The detection and...1 IDENTIFICATION OF BACTERIA USING PHYLOGENETIC RELATIONSHIPS REVEALED BY MS/MS SEQUENCING OF TRYPTIC PEPTIDES DERIVED FROM CELLULAR PROTEINS...based on analysis of an electrospray ionization (ESI)-MS/MS data for the fast classification of analyzed bacteria, using phylogenetic relationships

  4. Isomer-Specific Analysis of Released N-Glycans by LC-ESI MS/MS with Porous Graphitized Carbon.

    PubMed

    Kolarich, Daniel; Windwarder, Markus; Alagesan, Kathirvel; Altmann, Friedrich

    2015-01-01

    The combination of porous graphitized carbon (PGC) liquid chromatography (LC) with mass spectrometric (MS) detection probably constitutes the most elaborate single stage analysis for isomer-specific N-glycan analysis. Here, we describe sample preparation and analysis procedures for the identification of released N-glycans using PGC-LC-ESI-MS and MS/MS.

  5. Development of LC-MS/MS method for analysis of polyphenolic compounds in juice, tea and coffee samples

    USDA-ARS?s Scientific Manuscript database

    A simple and fast method for the analysis of a wide range of polyphenolic compounds in juice, tea, and coffee samples was developed using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The method was based on a simple sample preparation “dilute and shoot” approach, and LC-MS/MS triple qu...

  6. MASIC: a software program for fast quantitation and flexible visualization of chromatographic profiles from detected LC-MS(/MS) features

    SciTech Connect

    Monroe, Matthew E.; Shaw, Jason L.; Daly, Don S.; Adkins, Joshua N.; Smith, Richard D.

    2008-06-01

    Quantitative analysis of liquid chromatography (LC)- mass spectrometry (MS) and tandem mass spectrometry (MS/MS) data is essential to many proteomics studies. We have developed MASIC to accurately measure peptide abundances and LC elution times in low-resolution LC-MS/MS analyses. This software program uses an efficient processing algorithm to quickly generate mass specific selected ion chromatograms from a dataset and provides an interactive browser that allows users to examine individual chromatograms in a variety of fashions. The improved elution time estimates afforded by MASIC increase the utility of LC-MS/MS data in the accurate mass and time (AMT) tag approach to proteomics.

  7. EXTRACTION AND DETECTION OF A NEW ARSINE SULFIDE CONTAINING ARSENOSUGAR IN MOLLUSCS BY IC-ICP-MS AND IC-ESI-MS/MS

    EPA Science Inventory

    Using IC-ICP-MS and IC-ESI-MS/MS, an unknown arsenical compound in mollusks has been identified as a new arsine sulfide containing analog of a known arsenosugar and is referred to as As(498). This species has been observed in four separate shellfish species following a mild metha...

  8. Quantitative Determination of Perfluorochemicals and Fluorotelomer Alcohols in Plants from Biosolid-Amended Fields using LC/MS/MS and GC/MS

    EPA Science Inventory

    Analytical methods for determining perfluorochemicals (PFCs) and fluorotelomer alcohols (FTOHs) in plants using liquid chromatography/tandem mass spectrometry (LC/MS/MS) and gas chromatography/mass spectrometry (GC/MS) were developed, and applied to quantify a suite of analytes i...

  9. Quantitative Determination of Perfluorochemicals and Fluorotelomer Alcohols in Plants from Biosolid-Amended Fields using LC/MS/MS and GC/MS

    EPA Science Inventory

    Analytical methods for determining perfluorochemicals (PFCs) and fluorotelomer alcohols (FTOHs) in plants using liquid chromatography/tandem mass spectrometry (LC/MS/MS) and gas chromatography/mass spectrometry (GC/MS) were developed, and applied to quantify a suite of analytes i...

  10. Analysis of Phosphonic Acids: Validation of Semi-Volatile Analysis by HPLC-MS/MS by EPA Method MS999

    SciTech Connect

    Owens, J; Vu, A; Koester, C

    2008-10-31

    The Environmental Protection Agency's (EPA) Region 5 Chicago Regional Laboratory (CRL) developed a method titled Analysis of Diisopropyl Methylphosphonate, Ethyl Hydrogen Dimethylamidophosphate, Isopropyl Methylphosphonic Acid, Methylphosphonic Acid, and Pinacolyl Methylphosphonic Acid in Water by Multiple Reaction Monitoring Liquid Chromatography/Tandem Mass Spectrometry: EPA Version MS999. This draft standard operating procedure (SOP) was distributed to multiple EPA laboratories and to Lawrence Livermore National Laboratory, which was tasked to serve as a reference laboratory for EPA's Environmental Reference Laboratory Network (ERLN) and to develop and validate analytical procedures. The primary objective of this study was to validate and verify the analytical procedures described in EPA Method MS999 for analysis of the listed phosphonic acids and surrogates in aqueous samples. The gathered data from this validation study will be used to: (1) demonstrate analytical method performance; (2) generate quality control acceptance criteria; and (3) revise the SOP to provide a validated method that would be available for use during a homeland security event. The data contained in this report will be compiled, by EPA CRL, with data generated by other EPA Regional laboratories so that performance metrics of EPA Method MS999 can be determined.

  11. High Throughput Analytical Techniques for the Determination and Confirmation of Residues of 653 Multiclass Pesticides and Chemical Pollutants in Tea by GC/MS, GC/MS/MS, and LC/MS/MS: Collaborative Study, First Action 2014.09.

    PubMed

    Pang, Guo-Fang; Fan, Chun-Lin; Cao, Yan-Zhong; Yan, Fang; Li, Yan; Kang, Jian; Chen, Hui; Chang, Qiao-Ying

    2015-01-01

    Thirty laboratories from fom North and South America, Europe, and Asia participated in this AOAC collaborative study (15 from China; five from Germany; two each from Italy and the United States; and one each from the Republic of Korea, Canada, Spain, Japan, Belgium, and India). Participants represented government regulatory, commercial testing, university, research institute, and private laboratories. The single-laboratory validated (SLV) tea method was evaluated in the collaborative study to determine the recovery and reproducibility of the method under multilaboratory conditions. Since there were no restrictions regarding the type of analytical instrumentation to use for the analyses, laboratories used a combination of equipment that included GC/MS, GC/MS/MS, and LC/MS/MS instruments from 22 different manufacturers, 21 brands of GC and LC columns, 13 different GC temperature programming profiles, 11 LC gradient elution programs, and six different vendor manufactured SPE cartridges. Even though all the analytical performance parameters for all the 653 compounds had been determined in the SLV study, guidance was obtained from an expert review panel of the AOAC Method-Centric Committee on Pesticide Residues to conduct the multilaboratory collaborative study based on 20 selected compounds that can be analyzed by GC/MS and 20 compounds that can be analyzed by LC/MS/MS. Altogether, 560 samples covering the 40 selected pesticides were analyzed in the study. These samples included green tea and oolong tea samples fortified typically at the European Union maximum residue limit for regulatory guidance and compliance, aged tea samples incurred with 20 pesticides, and green tea and oolong tea samples incurred with five pesticides. The analysis of the 560 samples generated a total of 82 459 test results by the 30 participating laboratories. One laboratory failed to meet the proficiency requirements in the precollaborative study. Therefore, its data submitted for the

  12. Quantification of Free Carnitine and Acylcarnitines in Plasma or Serum Using HPLC/MS/MS.

    PubMed

    Scott, David; Heese, Bryce; Garg, Uttam

    2016-01-01

    Acylcarnitines are formed by esterification between fatty acids CoA or organic acids CoA molecules and carnitine. In various fatty acids oxidation defects and organic acidurias, there is increased concentration of corresponding acylcarnitines. Abnormalities in specific acylcarnitines are used in the diagnosis of fatty acids oxidation defects and organic acidurias. Most commonly used method for the assay of acylcarnitines is HPLC-tandem mass spectrometry (HPLC/MS/MS). A HPLC/MS/MS method is described for the quantification of number of acylcarnitines. The method involves butylation of carnitine/acylcarnitines using acidified butanol, HPLC flow injection, and measurement of acylcarnitines using precursor ion scan and multiple reactions monitoring (MRM).

  13. Measurement of free carnitine and acylcarnitines in plasma by HILIC-ESI-MS/MS without derivatization.

    PubMed

    Peng, Minzhi; Liu, Li; Jiang, Minyan; Liang, Cuili; Zhao, Xiaoyuan; Cai, Yanna; Sheng, Huiying; Ou, Zhiying; Luo, Hong

    2013-08-01

    Measurement of carnitine and acylcarnitines in plasma is important in diagnosis of fatty acid β-oxidation disorders and organic acidemia. The usual method uses flow injection tandem mass spectrometry (FIA-MS/MS), which has limitations. A rapid and more accurate method was developed to be used for high-risk screening and diagnosis. Carnitine and acylcarnitines were separated by hydrophilic interaction liquid chromatography (HILIC) without derivatization and detected with a QTRAP MS/MS System. Total analysis time was 9.0min. The imprecision of within- and between-run were less than 6% and 17%, respectively. Recoveries were in the range of 85-110% at three concentrations. Some acylcarnitine isomers could be separated, such as dicarboxylic and hydroxyl acylcarnitines. The method could also separate interferent to avoid false positive results. 216 normal samples and 116 patient samples were detected with the validated method, and 49 patients were identified with fatty acid oxidation disorders or organic acidemias.

  14. Development of LC-MS/MS analysis of cyclic dipeptides and its application to tea extract.

    PubMed

    Yamamoto, Kenji; Hayashi, Miki; Murakami, Yuka; Araki, Yoko; Otsuka, Yuuki; Kashiwagi, Takehiro; Shimamura, Tomoko; Ukeda, Hiroyuki

    2015-01-01

    2,5-Diketopiperazines (DKPs), also called cyclic dipeptides, have been known to occur in various foods. Recently, DKPs have attracted attentions as bioactive components. There were some reports on analytical methods for DKPs, but the number of analyzed DKPs was only a part of all DKPs and the quantitative performance was not studied in detail. In this study, we selected 31 kinds of DKPs and developed a quantitative and simultaneous analytical method using LC-MS/MS. This method was applied to DKPs determination in Pu-erh tea, post-fermentation tea, and 18 kinds of DKPs were determined at concentration of 0.0017-0.11 ppm. As a result of spiked test, it was concluded that the developed method using LC-MS/MS was useful for estimating DKPs concentration in tea.

  15. Determination of hydrogen cyanide in cigarette mainstream smoke by LC/MS/MS.

    PubMed

    Mottier, Nicolas; Jeanneret, Florent; Rotach, Michel

    2010-01-01

    An LC/MS/MS method is presented for the determination of hydrogen cyanide in cigarette mainstream smoke. Cyanide is derivatized with 2,3'-naphthalenedicarboxaldehyde and taurine to form a benzo[f]isoindole derivative, which is then analyzed by LC/MS/MS. Isotopic KCN (K13C15N) was used as an internal standard. The regression equation was linear within the range 2.4-331 ng/mL for cyanide with a correlation coefficient > 0.999. The LOD was calculated as 4.1 ng/cigarette. The influence of the sodium hydroxide trapping solution concentration on the results is discussed. A 1 M solution showed the best results in terms of sample stability and trapping efficiency. The method proved to be robust, reliable, and more selective than current methods, making it a logical choice for determination of total cyanide in cigarette smoke.

  16. MS fragment isotope ratio analysis for evaluation of citrus essential oils by HRGC-MS.

    PubMed

    Satake, Atsushi; Furukawa, Kiyoshi; Ueno, Takao; Ukeda, Hiroyuki; Sawamura, Masayoshi

    2004-02-01

    To evaluate the origin of citrus essential oils, the isotope ratio of fragment peaks on HRGC-MS of the volatile compounds from various citrus oils was measured. The MS fragment ratio was found by the ratio of fragment peak intensity, m+1/m (m/z). This ratio reflects the isotope effect of volatile compounds, that is, it provides information about locality, quality, and species for essential oils. Multivariate analysis based on the MS fragment ratio of monoterpene hydrocarbons clearly distinguished three citrus species, yuzu, lemon, and lime. The carbonyl fractions were also extracted from citrus essential oils by the sodium hydrogensulfite method. The isotope ratio of MS fragments of octanal, nonanal, and decanal was also examined. The results suggest that there was no significant difference in the individual fragment isotope ratios of the three aldehydes.

  17. Glyco- and sphingophosphonolipids from the medusa Phyllorhiza punctata: NMR and ESI-MS/MS fingerprints.

    PubMed

    de Souza, Lauro M; Iacomini, Marcello; Gorin, Philip A J; Sari, Roger S; Haddad, Maria A; Sassaki, Guilherme L

    2007-02-01

    The medusa Phyllorhiza punctata has been found in Brazilian waters where it is an exotic species, having arrived in ballasts from the Indo-Pacific Ocean in the general region of North Australia and Indonesia. Fatty acids of the intact animal and its component umbrella, oral arms, and mucus were identified. Two different groups of glycolipids and a sphingolipid were isolated by silica-gel column chromatography and characterized using GC-MS, ESI-MS, 1D, 2D (13)C, (1)H and (31)P NMR spectroscopy. They were sulfoquinovosyldiacylglycerol (SQDG), monogalactosyldiacylglycerol (MGDG), and ceramide aminoethylphosphonate (CAEP). The CAEP long chain base (LCB) and its polar head group (PHG) formed by partial hydrolysis, were analyzed by ESI-MS/MS. The probable origin of MGDG and SQDG in the jellyfish is the result of an endosymbiotic association with a microalga of the Dinoflagellate group, since these lipids are commonly found in photosynthetic membranes.

  18. LC-MS/MS quantitation of antimalarial drug piperaquine and metabolites in human plasma.

    PubMed

    Aziz, Mohd Yusmaidie; Hoffmann, Kurt-Jürgen; Ashton, Michael

    2017-09-15

    This study aimed to develop a sensitive, quantitative assay for the antimalarial piperaquine (PQ) and its metabolites M1 and M2 in human plasma. Analytes were gradiently separated on a C18 column and detected with a Sciex API 4000 MS/MS with an ESI source operated in the positive ion mode with deuterated PQ as internal standard. The response was linear in the range 3.9-2508nM with a runtime of 7.0min per sample. The method was applied to clinical samples from healthy volunteers. This LC-MS/MS method for the simultaneous quantitation of PQ and two of its metabolites in plasma may prove helpful for assessment of metabolite safety issues in vivo. Copyright © 2017. Published by Elsevier B.V.

  19. Characterization of phenolic composition in Lamiaceae spices by LC-ESI-MS/MS.

    PubMed

    Hossain, Mohammad B; Rai, Dilip K; Brunton, Nigel P; Martin-Diana, Ana B; Barry-Ryan, Catherine

    2010-10-13

    A total of 38 phenolic compounds in the solid/liquid extracts of five Lamiaceae spices, rosemary, oregano, sage, basil, and thyme, were identified in the present study using LC-ESI-MS/MS. These compounds were distributed in four major categories, namely, hydroxycinnamic acid derivatives, hydroxybenzoic acid derivatives, flavonoids, and phenolic terpenes. Among them, the category of flavonoids was the largest, with 17 compounds. Identification of the phenolic compounds was carried out by comparing retention times and mass spectra with those of authentic standards. If standards were unavailable, phenolic compounds were identified on the basis of accurate mass of pseudomolecular [M - H](-) ions and tandem mass spectrometry (MS/MS) data. The results of accurate mass measurements fit well with the elemental composition of the compounds. The diagnostic fragmentation patterns of the compounds during collision-induced dissociation (CID) elucidated the structural information of the compounds analyzed.

  20. Mannose7 Glycan Isomer Characterization by IMS-MS/MS Analysis

    PubMed Central

    Zhu, Feifei; Lee, Sunyoung; Valentine, Stephen J.; Reilly, James P.; Clemmer, David E.

    2012-01-01

    The isomers of the Man7GlcNAc2 glycan obtained from bovine ribonuclease B have been characterized by ion mobility spectrometry-tandem mass spectrometry (IMS-MS/MS). In these experiments, [Man7+2Na]2+ precursors having different mobilities are selected by ion mobility spectrometry and analyzed by MS/MS techniques in an ion trap. The fragmentation spectra obtained for various precursor ions are specific, suggesting the isolation or enrichment of different glycan isomers. One fragment ion with a mass-to-charge ratio (m/z) of 903.8 is found to correspond to the loss of an internal mannose residue of a specific isomer. Extracted fragment ion drift time distributions (XFIDTDs) yield distinctive precursor ion drift time profiles indicating the existence of four separate isomers as proposed previously. PMID:23055077

  1. [Simultaneous determination of pesticide residues in agricultural products by LC-MS/MS].

    PubMed

    Watanabe, Minae; Ueno, Eiji; Inoue, Tomomi; Ohno, Haruka; Ikai, Yoshitomo; Morishita, Toshio; Oshima, Harumi; Hayashi, Rumiko

    2013-01-01

    A method for the simultaneous determination of multiple pesticide residues in agricultural products was developed by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). The sample was extracted with acetonitrile. Co-extractives were removed by GPC/graphitized carbon column SPE, and silica gel/PSA cartridge column SPE. Pesticides in the test solution were determined by LC-MS/MS using scheduled MRM. Recoveries of 124 pesticides from spinach, brown rice, soybean, orange and tomato were tested at the level of 0.1 µg/g, and those of 121 pesticides ranged from 70 to 120% (RSD≤15%). Pesticide residues in 239 agricultural products were investigated by this method, and residues of 49 pesticides were detected in 98 agricultural products.

  2. Tempest: Accelerated MS/MS Database Search Software for Heterogeneous Computing Platforms.

    PubMed

    Adamo, Mark E; Gerber, Scott A

    2016-09-07

    MS/MS database search algorithms derive a set of candidate peptide sequences from in silico digest of a protein sequence database, and compute theoretical fragmentation patterns to match these candidates against observed MS/MS spectra. The original Tempest publication described these operations mapped to a CPU-GPU model, in which the CPU (central processing unit) generates peptide candidates that are asynchronously sent to a discrete GPU (graphics processing unit) to be scored against experimental spectra in parallel. The current version of Tempest expands this model, incorporating OpenCL to offer seamless parallelization across multicore CPUs, GPUs, integrated graphics chips, and general-purpose coprocessors. Three protocols describe how to configure and run a Tempest search, including discussion of how to leverage Tempest's unique feature set to produce optimal results. © 2016 by John Wiley & Sons, Inc.

  3. Determination of hydroxytriazines in ground water by HPLC-MS-MS

    SciTech Connect

    Gresham, M.E.; Li, Yong-Xi; Fieser, J.A.; Manuli, P.E.

    1996-10-01

    Details of an analytical method re presented for the concentration, purification, and HPLC-MS-MS analysis for hydroxyatrazine (G-34048), hydroxysimazine (G-30414) and the three dealkylated hydroxy metabolites, GS-17794, GS-17792, and GS-17791. The water sample is acidified, analytes are adsorbed to a solid phase SCX column, and the analytes are eluted with a mixture of methanol, water, and ammonium hydroxide. The eluant from the solid phase extraction is removed and the extract reconstituted with methanol water. Quantitation of the extracts using HPLC-MS-MS with a minimum quantitation limit of 0.1 ng/L has given recoveries of 77 {plus_minus} 14%, 82 {plus_minus} 14%, 93 {plus_minus} 12%, 92 {plus_minus} 13%, and 93 {plus_minus} 11% for each of the five analytes for 165 fortified controls analyzed during the study.

  4. The APEX Quantitative Proteomics Tool: Generating protein quantitation estimates from LC-MS/MS proteomics results

    PubMed Central

    Braisted, John C; Kuntumalla, Srilatha; Vogel, Christine; Marcotte, Edward M; Rodrigues, Alan R; Wang, Rong; Huang, Shih-Ting; Ferlanti, Erik S; Saeed, Alexander I; Fleischmann, Robert D; Peterson, Scott N; Pieper, Rembert

    2008-01-01

    Background Mass spectrometry (MS) based label-free protein quantitation has mainly focused on analysis of ion peak heights and peptide spectral counts. Most analyses of tandem mass spectrometry (MS/MS) data begin with an enzymatic digestion of a complex protein mixture to generate smaller peptides that can be separated and identified by an MS/MS instrument. Peptide spectral counting techniques attempt to quantify protein abundance by counting the number of detected tryptic peptides and their corresponding MS spectra. However, spectral counting is confounded by the fact that peptide physicochemical properties severely affect MS detection resulting in each peptide having a different detection probability. Lu et al. (2007) described a modified spectral counting technique, Absolute Protein Expression (APEX), which improves on basic spectral counting methods by including a correction factor for each protein (called Oi value) that accounts for variable peptide detection by MS techniques. The technique uses machine learning classification to derive peptide detection probabilities that are used to predict the number of tryptic peptides expected to be detected for one molecule of a particular protein (Oi). This predicted spectral count is compared to the protein's observed MS total spectral count during APEX computation of protein abundances. Results The APEX Quantitative Proteomics Tool, introduced here, is a free open source Java application that supports the APEX protein quantitation technique. The APEX tool uses data from standard tandem mass spectrometry proteomics experiments and provides computational support for APEX protein abundance quantitation through a set of graphical user interfaces that partition thparameter controls for the various processing tasks. The tool also provides a Z-score analysis for identification of significant differential protein expression, a utility to assess APEX classifier performance via cross validation, and a utility to merge multiple

  5. Quantitation of Total Buprenorphine and Norbuprenorphine in Meconium by LC-MS/MS.

    PubMed

    Marin, Stephanie J; McMillin, Gwendolyn A

    2016-01-01

    Buprenorphine (Suboxone, Zubsolv, Buprenex, Butrans, etc.) is an opioid drug that has been used to treat opioid dependence on an outpatient basis, and is also prescribed for managing moderate to severe pain. Pregnant women may be prescribed buprenorphine as part of a treatment plan for opioid addiction. This chapter quantitates buprenorphine and norbuprenorphine in meconium by liquid chromatography tandem mass spectrometry (LC-MS/MS).

  6. STS-33 MS Carter and MS Thornton display 'Maggot on Board' sign and candy

    NASA Technical Reports Server (NTRS)

    1989-01-01

    STS-33 Mission Specialist (MS) Manley L. Carter, Jr (left) and MS Kathryn C. Thornton display 'Maggot on Board' sign and 'SMARTIES' candy stored in plastic bag on the aft flight deck of Discovery, Orbiter Vehicle (OV) 103. The mission specialists are wearing their mission polo shirts and communications kit assembly headsets. An overhead window appears above their heads. A gold necklace chain floats around Carter's neck.

  7. STS-35 MS Hoffman's height is recorded by MS Lounge on OV-102's middeck

    NASA Technical Reports Server (NTRS)

    1990-01-01

    STS-35 Mission Specialist (MS) Jeffrey A. Hoffman stretches out on the middeck floor while MS John M. Lounge records his height. The two crewmembers are in front of the forward lockers aboard Columbia, Orbiter Vehicle (OV) 102. Hoffman steadies himself using the stowed treadmill and the lockers. Above Hoffman's head is a plastic bag filled with Development Test Objective (DTO) 634, Trash Compaction and Retention System Demonstration, trash compactor charcoal filtered bag lids.

  8. STS-37 MS Godwin balances MS Ross using her index finger on OV-104's middeck

    NASA Technical Reports Server (NTRS)

    1991-01-01

    STS-37 Mission Specialist (MS) Linda M. Godwin holds MS Jerry L. Ross over her head using only her index finger. The two crewmembers are participating in a microgravity balancing act on the middeck of Atlantis, Orbiter Vehicle (OV) 104. The Bioserve Instrumentation Technology Associates Materials Dispersion Apparatus (BIMDA) bioprocessing test bed mixing and sampling configuration is attached to the forward middeck lockers at Ross' right. The sleep restraints are attached on the starboard wall behind the astronauts.

  9. STS-47 MS Davis and MS/PLC Lee during JSC bailout training

    NASA Technical Reports Server (NTRS)

    1992-01-01

    STS-47 Endeavour, Orbiter Vehicle (OV) 105, Mission Specialist (MS) N. Jan Davis (left) and MS and Payload Commander (PLC) Mark C. Lee take a break from bailout (launch egress training) held in JSC's Mockup and Training Laboratory (MAIL) Bldg 9A. The two crewmembers, wearing launch and entry suits (LESs) and communications carrier assemblies (CCAs), are standing in front of the crew compartment trainer (CCT).

  10. STS-35 MS Hoffman and MS Parker on the middeck of Columbia, OV-102

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Posing on the middeck of Columbia, Orbiter Vehicle (OV) 102, are Mission Specialist (MS) Jeffrey A. Hoffman (mustache) and MS Robert A. R. Parker. Determining who is right side up is complicated by the microgravity of space. Hoffman's head is at the middeck floor and his feet are at the ceiling. The two crewmembers are in front of OV-102's port side with the waste collection system (WCS) contingency unit, side hatch, and galley visible behind them.

  11. Algorithms for database-dependent search of MS/MS data.

    PubMed

    Matthiesen, Rune

    2013-01-01

    The frequent used bottom-up strategy for identification of proteins and their associated modifications generate nowadays typically thousands of MS/MS spectra that normally are matched automatically against a protein sequence database. Search engines that take as input MS/MS spectra and a protein sequence database are referred as database-dependent search engines. Many programs both commercial and freely available exist for database-dependent search of MS/MS spectra and most of the programs have excellent user documentation. The aim here is therefore to outline the algorithm strategy behind different search engines rather than providing software user manuals. The process of database-dependent search can be divided into search strategy, peptide scoring, protein scoring, and finally protein inference. Most efforts in the literature have been put in to comparing results from different software rather than discussing the underlining algorithms. Such practical comparisons can be cluttered by suboptimal implementation and the observed differences are frequently caused by software parameters settings which have not been set proper to allow even comparison. In other words an algorithmic idea can still be worth considering even if the software implementation has been demonstrated to be suboptimal. The aim in this chapter is therefore to split the algorithms for database-dependent searching of MS/MS data into the above steps so that the different algorithmic ideas become more transparent and comparable. Most search engines provide good implementations of the first three data analysis steps mentioned above, whereas the final step of protein inference are much less developed for most search engines and is in many cases performed by an external software. The final part of this chapter illustrates how protein inference is built into the VEMS search engine and discusses a stand-alone program SIR for protein inference that can import a Mascot search result.

  12. STS-47 MS Davis and MS/PLC Lee during JSC bailout training

    NASA Technical Reports Server (NTRS)

    1992-01-01

    STS-47 Endeavour, Orbiter Vehicle (OV) 105, Mission Specialist (MS) N. Jan Davis (left) and MS and Payload Commander (PLC) Mark C. Lee take a break from bailout (launch egress training) held in JSC's Mockup and Training Laboratory (MAIL) Bldg 9A. The two crewmembers, wearing launch and entry suits (LESs) and communications carrier assemblies (CCAs), are standing in front of the crew compartment trainer (CCT).

  13. STS-53 MS Bluford and MS Voss during launch emergency egress training at JSC

    NASA Technical Reports Server (NTRS)

    1992-01-01

    STS-53 Discovery, Orbiter Vehicle (OV) 103, Mission Specialist (MS) Guion S. Bluford (left) and MS James S. Voss, wearing launch and entry suits (LESs), listen to instructions prior to launch emergency egress bailout training. Bluford and Voss, along with the other STS-53 crewmembers, will practice bailout procedures in JSC's crew compartment trainer (CCT) located in the Mockup and Integration Laboratory (MAIL) Bldg 9NE.

  14. STS-53 MS Bluford and MS Voss during launch emergency egress training at JSC

    NASA Image and Video Library

    1992-11-10

    S92-49644 (1994) --- STS-53 Discovery, Orbiter Vehicle (OV) 103, Mission Specialist (MS) Guion S. Bluford (left) and MS James S. Voss, wearing launch and entry suits (LESs), listen to instructions prior to launch emergency egress bailout training. Bluford and Voss, along with the other STS-53 crewmembers, will practice bailout procedures in JSC's crew compartment trainer (CCT) located in the Mockup and Integration Laboratory (MAIL) Bldg 9NE

  15. STS-33 MS Carter and MS Thornton display 'Maggot on Board' sign and candy

    NASA Technical Reports Server (NTRS)

    1989-01-01

    STS-33 Mission Specialist (MS) Manley L. Carter, Jr (left) and MS Kathryn C. Thornton display 'Maggot on Board' sign and 'SMARTIES' candy stored in plastic bag on the aft flight deck of Discovery, Orbiter Vehicle (OV) 103. The mission specialists are wearing their mission polo shirts and communications kit assembly headsets. An overhead window appears above their heads. A gold necklace chain floats around Carter's neck.

  16. Quantitative LC-MS/MS Analysis of Proteins Involved in Metastasis of Breast Cancer

    PubMed Central

    Goto, Rieko; Nakamura, Yasushi; Takami, Tomonori; Sanke, Tokio; Tozuka, Zenzaburo

    2015-01-01

    The purpose of this study was to develop quantitative liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods for the analysis of proteins involved in metastasis of breast cancer for diagnosis and determining disease prognosis, as well as to further our understand of metastatic mechanisms. We have previously demonstrated that the protein type XIV collagen may be specifically expressed in metastatic tissues by two dimensional LC-MS/MS. In this study, we developed quantitative LC-MS/MS methods for type XIV collagen. Type XIV collagen was quantified by analyzing 2 peptides generated by digesting type XIV collagen using stable isotope-labeled peptides. The individual concentrations were equivalent between 2 different peptides of type XIV collagen by evaluation of imprecise transitions and using the best transition for the peptide concentration. The results indicated that type XIV collagen is highly expressed in metastatic tissues of patients with massive lymph node involvement compared to non-metastatic tissues. These findings were validated by quantitative real-time RT-PCR. Further studies on type XIV collagen are desired to verify its role as a prognostic factor and diagnosis marker for metastasis. PMID:26176947

  17. Relationship between plasma and salivary melatonin and cortisol investigated by LC-MS/MS.

    PubMed

    van Faassen, Martijn; Bischoff, Rainer; Kema, Ido P

    2017-08-28

    Disturbance of the circadian rhythm has been associated with disease states, such as metabolic disorders, depression and cancer. Quantification of the circadian markers such as melatonin and cortisol critically depend on reliable and reproducible analytical methods. Previously, melatonin and cortisol were primarily analyzed separately, mainly using immunoassays. Here we describe the validation and application of a high-throughput liquid chromatography in combination with mass spectrometry (LC-MS/MS) method for the combined analysis of melatonin and cortisol in plasma and saliva. The LC-MS/MS method was validated according to international validation guidelines. We used this method to analyze total plasma, free plasma (as obtained by equilibrium dialysis) and saliva melatonin and cortisol in healthy adults. Validation results for plasma and saliva melatonin and cortisol were well within the international validation criteria. We observed no difference between saliva collected by passive drooling or Salivette. Moreover, we noted a significant difference in saliva vs. free plasma melatonin. We observed on average 36% (95% CI: 4%-60%) higher salivary melatonin levels in comparison to free plasma melatonin, suggestive of local production of melatonin in the salivary glands. The novel outcome of this study is probably due to the high precision of our LC-MS/MS assay. These outcomes illustrate the added value of accurate and sensitive mass spectrometry based methods for the quantification of neuroendocrine biomarkers.

  18. Recent advances in high-throughput quantitative bioanalysis by LC-MS/MS.

    PubMed

    Xu, Raymond Naxing; Fan, Leimin; Rieser, Matthew J; El-Shourbagy, Tawakol A

    2007-06-28

    Liquid chromatography linked to tandem mass spectrometry (LC-MS/MS) has played an important role in pharmacokinetics and metabolism studies at various drug development stages since its introduction to the pharmaceutical industry. This article reviews the most recent advances in sample preparation, separation, and the mass spectrometric aspects of high-throughput quantitative bioanalysis of drug and metabolites in biological matrices. Newly introduced techniques such as ultra-performance liquid chromatography with small particles (sub-2 microm) and monolithic chromatography offer improvements in speed, resolution and sensitivity compared to conventional chromatographic techniques. Hydrophilic interaction chromatography (HILIC) on silica columns with low aqueous/high organic mobile phase is emerging as a valuable supplement to the reversed-phase LC-MS/MS. Sample preparation formatted to 96-well plates has allowed for semi-automation of off-line sample preparation techniques, significantly impacting throughput. On-line solid-phase extraction (SPE) utilizing column-switching techniques is rapidly gaining acceptance in bioanalytical applications to reduce both time and labor required to produce bioanalytical results. Extraction sorbents for on-line SPE extend to an array of media including large particles for turbulent flow chromatography, restricted access materials (RAM), monolithic materials, and disposable cartridges utilizing traditional packings such as those used in Spark Holland systems. In the end, this paper also discusses recent studies of matrix effect in LC-MS/MS analysis and how to reduce/eliminate matrix effect in method development and validation.

  19. Determination of buprenorphine, fentanyl and LSD in whole blood by UPLC-MS-MS.

    PubMed

    Berg, Thomas; Jørgenrud, Benedicte; Strand, Dag Helge

    2013-04-01

    A sensitive ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS-MS) method has been developed and validated for the quantification of buprenorphine, fentanyl and lysergic acid diethylamide (LSD) in whole blood. Sample preparation was performed by liquid-liquid extraction (LLE) with methyl tert-butyl ether. UPLC-MS-MS analysis was performed with a mobile phase consisting of ammonium formate (pH 10.2) and methanol. Positive electrospray ionization MS-MS detection was performed with two multiple reaction monitoring transitions for each of the analytes and the deuterium labeled internal standards. Limit of detection values of buprenorphine, fentanyl and LSD were 0.28, 0.044 and 0.0097 ng/mL and limit of quantification values were 0.94, 0.14 and 0.036 ng/mL, respectively. Most phospholipids were removed during LLE. No or only minor matrix effects were observed. The method has been routinely used at the Norwegian Institute of Public Health since September 2011 for qualitative and quantitative detections of buprenorphine, fentanyl and/or LSD in more than 400 whole blood samples with two replicates per sample.

  20. Determination and pharmacokinetics of amygdalin in rats by LC-MS-MS.

    PubMed

    Li, Xiao-bo; Liu, Chang-hui; Zhang, Rong; Huang, Xiao-tao; Li, Ying-yi; Han, Liang; Xu, Mei-li; Mi, Sui-qing; Wang, Ning-sheng

    2014-07-01

    A sensitive and specific liquid chromatography-tandem mass spectrometric (LC-MS-MS) method was developed for the determination and pharmacokinetics of amygdalin in rats. Rat plasma pretreated by solid-phase extraction was analyzed by LC-MS-MS with negative electrospray ionization in the multiple reaction monitoring mode. Amygdalin and geniposide [the internal standard (IS)] were separated on a C18 column eluted with a mobile phase of methanol and water (85:15; v/v) at a flow rate of 0.25 mL/min in a run time of 3.0 min. The precursor to product ion transitions were monitored at m/z 457.2 → 279.1 for amygdalin and m/z 387.1 → 224.9 for the IS. The calibration curve of amygdalin showed good linearity over a concentration range of 10-2,000 ng/mL. The limit of quantification was 10 ng/mL. Intra-day and inter-day precisions and accuracy (percent relative standard deviation) were both within 10%. The method was fully validated for its selectivity, sensitivity, matrix effect, recovery and stability. This accurate and specific assay produced a useful LC-MS-MS method, which was successfully applied to pharmacokinetic studies after the oral administration of amygdalin to rats.

  1. Identification of RNA sequence isomer by isotope labeling and LC-MS/MS.

    PubMed

    Li, Siwei; Limbach, Patrick A

    2014-11-01

    Recently, we developed a method for modified ribonucleic acid (RNA) analysis based on the comparative analysis of RNA digests (CARD). Within this CARD approach, sequence or modification differences between two samples are identified through differential isotopic labeling of two samples. Components present in both samples will each be labeled, yielding doublets in the CARD mass spectrum. Components unique to only one sample should be detected as singlets. A limitation of the prior singlet identification strategy occurs when the two samples contain components of unique sequence but identical base composition. At the first stage of mass spectrometry, these sequence isomers cannot be differentiated and would appear as doublets rather than singlets. However, underlying sequence differences should be detectable by collision-induced dissociation tandem mass spectrometry (CID MS/MS), as y-type product ions will retain the original enzymatically incorporated isotope label. Here, we determine appropriate instrumental conditions that enable CID MS/MS of isotopically labeled ribonuclease T1 (RNase T1) digestion products such that the original isotope label is maintained in the product ion mass spectrum. Next, we demonstrate how y-type product ions can be used to differentiate singlets and doublets from isomer sequences. We were then able to extend the utility of this approach by using CID MS/MS for the confirmation of an expected RNase T1 digestion product within the CARD analysis of an Escherichia coli mutant strain even in the presence of interfering and overlapping digestion products from other transfer RNAs.

  2. [Simultaneous determination of quinolones in foods by LC/MS/MS].

    PubMed

    Hatano, Kazuhiro

    2004-10-01

    A simple method was developed for the simultaneous determination of seven quinolones (enoxacin, ofloxacin, ciprofloxacin, danofloxacin, lomefloxacin, enrofloxacin and sarafloxacin) in foods using liquid chromatography coupled with electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). The seven quinolones were extracted with acetonitrile containing 0.2% formic acid, and the extracted solution was cleaned up on a C18 cartridge. The extract was diluted with 5 mmol/L IPCC-MS3 for injection into the LC-ESI-MS/MS. The LC separation was carried out on an ODS column with gradient elution of 5 mmol/L IPCC-MS3-acetonitrile as the mobile phase. Mass spectral acquisition was done in the positive ion mode by applying selected reaction monitoring (SRM). The recoveries of the seven quinolones were mostly greater than 60% from foods fortified at 10 ng/g. The detection limits in foods were 2 ng/g for enoxacin and ciprofloxacin, and 1 ng/g for the other drugs. Twenty cattle muscle, 7 swine muscle, 9 chicken muscle, 16 milk, 19 prawn and 20 broiled eel samples from retail markets were analyzed by this method. Enrofloxacin and its metabolite ciprofloxacin were detected in 9 broiled eel at the level of trace (tr)-34 ng/g and tr-10 ng/g, respectively.

  3. UPLC-ESI-MS/MS analysis of Sudan dyes and Para Red in food.

    PubMed

    Li, C; Wu, Y L; Shen, J Z

    2010-09-01

    An analytical method for the simultaneous determination of Sudan dyes (Sudan Red G, Sudan I, Sudan II, Sudan III, Sudan Red 7B and Sudan IV) and Para Red in food by ultra-performance liquid chromatography-electrospray tandem mass spectrometry (UPLC-ESI-MS/MS) was developed. Samples were extracted with acetonitrile, and water added into the extract. The supernatant was analysed by UPLC-MS/MS after refrigeration and centrifugation. The sample was separated on an Acquity BEH C(18) column, and detected by MS/MS with the multiple reaction monitoring mode. Matrix calibration was used for quantitative testing of the method. The linear matrix calibrations of Sudan dyes and Para Red were 2-50 and 10-250 ng g(-1), respectively, and the regression coefficients were >0.9945. The recoveries were 83.4-112.3% with good coefficients of variation of 2.0-10.8%. The limits of detection were between 0.3 and 1.4 ng g(-1) for the six Sudan dyes, and between 3.7 and 6.0 ng g(-1) for Para Red. The limits of quantification were between 0.9 and 4.8 ng g(-1) for the six Sudan dyes, and between 12.2 and 19.8 ng g(-1) for Para Red.

  4. MS/MS analysis of the products of toluene photooxidation and measurement of their mutagenic activity

    SciTech Connect

    Dumdel, B.E.; Kenny, D.V.; Shepson, P.B.; Kleindienst, T.E.; Nero, C.M.; Cupitt, L.T.; Claxton, L.D.

    1988-12-01

    Products of the photooxidation of toluene from an irradiated 5.1 ppm toluene/0.9 ppm NO/sub x/ mixture were identified by use of a triple-quadrupole MS/MS operated in an atmospheric pressure ionization mode. The reaction was carried out in a flow-mode 22.7-m/sup 3/ Telfon smog chamber. The steady-state reactant and product mixture was continuously transferred to the mass spectrometer inlet at 144 L/min. By using structurally similar standards, semiquantitative MS/MS analyses for many of the ring fragmentation products were conducted. Quantitative analyses by chromatographic methods and semiquantitative analyses by MS/MS were conducted for a variety of ring fragmentation products. The following products were found with yields of 1% (C/C) or greater: methylglyoxal, glyoxal, benzaldehyde, methylbutenedial, hydroxy-methylbutenedial, peroxyacetyl nitrate, oxoheptadienal, CH/sub 3/COOH, HCHO, hexadienal, and hydroxyoxo-heptadienal. The mutagenic activity of the steady-state product mixture was measured by using the Ames assay Salmonella typhimurium strain TA 100. The mutagenic activity data are discussed relative to our earlier findings that resulted from different reaction conditions.

  5. Ultrafast Polyphenol Metabolomics of Red Wines Using MicroLC-MS/MS.

    PubMed

    Ma, Yan; Tanaka, Nobuo; Vaniya, Arpana; Kind, Tobias; Fiehn, Oliver

    2016-01-20

    The taste and quality of red wine are determined by its highly complex mixture of polyphenols and many other metabolites. No single method can fully cover the full metabolome, but even for polyphenols and related compounds, current methods proved inadequate. We optimized liquid chromatography resolution and sensitivity using 1 mm i.d. columns with microLC pumps and compared data-dependent to data-independent (SWATH) MS/MS acquisitions. A high-throughput microLC-MS method was developed with a 4 min gradient at 0.05 mL/min flow rate on a Kinetex C18 column and Sciex TripleTOF mass spectrometry. Using the novel software MS-DIAL, we structurally annotated 264 compounds including 165 polyphenols in six commercial red wines by accurate mass MS/MS matching. As proof of concept, multivariate statistics revealed the difference in the metabolite profiles of the six red wines, and regression analysis linked the polyphenol contents to the taste of the red wines.

  6. Analysis of coffee for the presence of acrylamide by LC-MS/MS.

    PubMed

    Andrzejewski, Denis; Roach, John A G; Gay, Martha L; Musser, Steven M

    2004-04-07

    A variety of popular instant, ground, and brewed coffees were analyzed using a modified liquid chromatography-tandem mass spectrometry (LC-MS/MS) method specifically developed for the determination of acrylamide in foods. Coffee test portions were spiked with 13C3-labeled acrylamide as an internal standard prior to their extraction and cleanup. Ground coffees (1 g) and instant coffees (0.5 g) were extracted by shaking with 9 mL of water for 20 min. Brewed coffee test portions (9 mL) were taken through the cleanup procedure without further dilution with extraction solvent. Coffee test portions were cleaned up by passing 1.5 mL first through an Oasis HLB (hydrophilic/lipophilic copolymer sorbent) solid phase extraction (SPE) cartridge and then a Bond Elut-Accucat (cation and anion exchange sorbent) SPE cartridge. The cleaned up extracts were analyzed by positive ion electrospray LC-MS/MS. The MS/MS data was used to detect, confirm, and quantitate acrylamide. The limit of quantitation of the method was 10 ng/g for ground and instant coffees and 1.0 ng/mL for brewed coffee. The levels of acrylamide ranged from 45 to 374 ng/g in unbrewed coffee grounds, from 172 to 539 ng/g in instant coffee crystals, and from 6 to 16 ng/mL in brewed coffee.

  7. Stable Isotope Labeled Tracers for Metabolic Pathway Elucidation by GC-MS and FT-MS

    PubMed Central

    Higashi, Richard M.; Fan, Teresa W-M.; Lorkiewicz, Pawel K.; Moseley, Hunter N.B.; Lane, Andrew N.

    2015-01-01

    Advances in analytical methodologies, principally nuclear magnetic resonance spectroscopy (NMR) and mass spectrometry (MS), over the last decade have made large-scale analysis of the human metabolome a reality. This is leading to the reawakening of the importance of metabolism in human diseases, particularly widespread metabolic diseases such as cancer, diabetes, and obesity. Emerging NMR and MS atom-tracking technologies and informatics is poised to revolutionize metabolomics-based research because they deliver the high information throughput (HIT) that is needed for deciphering systems biochemistry. In particular, Stable Isotope Resolved Metabolomics (SIRM) enables unambiguous tracking of individual atoms through compartmentalized metabolic networks, in a wide range of experimental systems, including human subjects. MS offers a wide range of initial capital outlay and operating costs, ranging from gas-chromatography (GC) MS affordable by many individual laboratories, to the HIT-supporting Fourier-transform (FT) class of MS that rivals NMR in cost and infrastructure support. This chapter will focus on sample preparation, instrument, and data processing procedures for these two extremes of MS instrumentation used in SIRM. PMID:25270929

  8. Confirmation of Drug Delivery after Liver Chemoembolization: Direct Tissue Doxorubicin Measurement by UHPLC-MS-MS

    PubMed Central

    Baumgarten, Sigrid; Gaba, Ron C.; van Breemen, Richard B.

    2012-01-01

    Because liver cancer is rarely suitable for surgery, transcatheter arterial chemoembolization (TACE) is used for palliative therapy. In this procedure, an emulsion of doxorubicin in iodized oil is injected directly into liver tumors through a catheter positioned within the artery supplying blood flow to the tumor. At present, there is limited understanding of factors affecting the delivery and dispersion of doxorubicin within treated tumors during TACE. This study addresses the development and application of an ultrahigh pressure liquid chromatography-tandem mass spectrometry (UHPLC-MS-MS) method for rapid confirmation of drug delivery after TACE in a rabbit VX2 liver cancer model. Doxorubicin levels in liver tumors were measured using UHPLC-MS-MS and compared with computed tomography measured levels of iodized oil, a metric used clinically to indicate drug delivery. We found that tissue drug levels determined using UHPLC-MS-MS did not correlate with the regional iodized oil concentration (vehicle) within tumors following TACE, suggesting that chemotherapeutic drugs like doxorubicin spread throughout tumors, and that lack of iodized oil staining in portions of a tumor does not necessarily indicate inadequate therapy during TACE. PMID:22454282

  9. Ultrahigh-throughput proteomics using fast RPLC separations with ESI-MS/MS.

    PubMed

    Shen, Yufeng; Smith, Richard D; Unger, Klaus K; Kumar, Dipika; Lubda, Dieter

    2005-10-15

    We describe approaches for proteomics analysis using electrospray ionization-tandem mass spectrometry coupled with fast reversed-phase liquid chromatography (RPLC) separations. The RPLC separations used 50-microm-i.d. fused-silica capillaries packed with submicrometer-sized C18-bonded porous silica particles and achieved peak capacities of 130-420 for analytes from proteome tryptic digests. When these separations were combined with linear ion trap tandem mass spectrometry measurements, approximately 1000 proteins could be identified in 50 min from approximately 4000 identified tryptic peptides; approximately 550 proteins in 20 min from approximately 1800 peptides; and approximately 250 proteins in 8 min from approximately 700 peptides for a S. oneidensis tryptic digest. The dynamic range for protein identification with the fast separations was determined to be approximately 3-4 orders of magnitude of relative protein abundance on the basis of known proteins in human blood plasma analyses. We found that 55% of the MS/MS spectra acquired during the entire analysis (and up to 100% of the MS/MS spectra acquired from the most data-rich zone) provided sufficient quality for identifying peptides. The results confirm that such analyses using very fast (minutes) RPLC separations based on columns packed with microsized porous particles are primarily limited by the MS/MS analysis speed.

  10. The EM Earthquake Precursor

    NASA Astrophysics Data System (ADS)

    Jones, K. B., II; Saxton, P. T.

    2013-12-01

    Many attempts have been made to determine a sound forecasting method regarding earthquakes and warn the public in turn. Presently, the animal kingdom leads the precursor list alluding to a transmission related source. By applying the animal-based model to an electromagnetic (EM) wave model, various hypotheses were formed, but the most interesting one required the use of a magnetometer with a differing design and geometry. To date, numerous, high-end magnetometers have been in use in close proximity to fault zones for potential earthquake forecasting; however, something is still amiss. The problem still resides with what exactly is forecastable and the investigating direction of EM. After the 1989 Loma Prieta Earthquake, American earthquake investigators predetermined magnetometer use and a minimum earthquake magnitude necessary for EM detection. This action was set in motion, due to the extensive damage incurred and public outrage concerning earthquake forecasting; however, the magnetometers employed, grounded or buried, are completely subject to static and electric fields and have yet to correlate to an identifiable precursor. Secondly, there is neither a networked array for finding any epicentral locations, nor have there been any attempts to find even one. This methodology needs dismissal, because it is overly complicated, subject to continuous change, and provides no response time. As for the minimum magnitude threshold, which was set at M5, this is simply higher than what modern technological advances have gained. Detection can now be achieved at approximately M1, which greatly improves forecasting chances. A propagating precursor has now been detected in both the field and laboratory. Field antenna testing conducted outside the NE Texas town of Timpson in February, 2013, detected three strong EM sources along with numerous weaker signals. The antenna had mobility, and observations were noted for recurrence, duration, and frequency response. Next, two

  11. LC-MS-based metabolomics: an update.

    PubMed

    Fang, Zhong-Ze; Gonzalez, Frank J

    2014-08-01

    Liquid chromatography-mass spectrometry (LC-MS)-based metabolomics can have a major impact in multiple research fields, especially when combined with other technologies, such as stable isotope tracers and genetically modified mice. This review highlights recent applications of metabolomic technology in the study of xenobiotic metabolism and toxicity, and the understanding of disease pathogenesis and therapeutics. Metabolomics has been employed to study metabolism of noscapine, an aryl hydrocarbon receptor antagonist, and to determine the mechanisms of liver toxicities of rifampicin and isoniazid, trichloroethylene, and gemfibrozil. Metabolomics-based insights into the pathogenesis of inflammatory bowel disease, alcohol-induced liver diseases, non-alcoholic steatohepatitis, and farnesoid X receptor signaling pathway-based therapeutic target discovery will also be discussed. Limitations in metabolomics technology such as sample preparation and lack of LC-MS databases and metabolite standards, need to be resolved in order to improve and broaden the application of metabolomic studies.

  12. [Potential pathogens in multiple sclerosis (MS)].

    PubMed

    Zawada, Mariola

    2012-10-22

     Multiple sclerosis is a neuroimmunological disease in which etiologic agents have not been identified yet. The etiology of MS is complex in its nature and may involve many different agents acting simultaneously or in a cascade manner leading to the development of the disease. The causes of MS development were sought among the factors associated with HLA and TCR genes and human endogenous retroviruses (HERV). Environmental factors such as bacterial, fungal and viral infections as well as potential participation of vitamin D in the pathogenesis of the disease have also been examined. The current state of knowledge concerning potential factors participating in the etiopathogenesis of multiple sclerosis has been reviewed in this paper.

  13. Isotopic ratio measurements with ICP-MS

    SciTech Connect

    Russ, G.P. III; Bazan, J.M.

    1986-06-03

    An inductively-coupled-plasma source mass spectrometer (ICP-MS) has been used to measure the isotopic composition of U, Pb, Os, and B standards. Particular emphasis has been placed on uranium because of its nuclear and environmental interest and because of the availability of a well-characterized set of standards with a wide range of isotopic compositions. The precision and accuracy obtainable in isotope ratio measurements by ICP-MS depend on many factors including background, interferences, dead time, mass fractionation (bias), abundance sensitivity, and counting statistics. Which, if any, of these factors controls accuracy and precision depends on the type of sample being analyzed and the characteristics of the mass spectrometer. These issues are discussed in detail.

  14. Greenhouse Gas Analysis by GC/MS

    NASA Astrophysics Data System (ADS)

    Bock, E. M.; Easton, Z. M.; Macek, P.

    2015-12-01

    Current methods to analyze greenhouse gases rely on designated complex, multiple-column, multiple-detector gas chromatographs. A novel method was developed in partnership with Shimadzu for simultaneous quantification of carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) in environmental gas samples. Gas bulbs were used to make custom standard mixtures by injecting small volumes of pure analyte into the nitrogen-filled bulb. Resulting calibration curves were validated using a certified gas standard. The use of GC/MS systems to perform this analysis has the potential to move the analysis of greenhouse gasses from expensive, custom GC systems to standard single-quadrupole GC/MS systems that are available in most laboratories, which wide variety of applications beyond greenhouse gas analysis. Additionally, use of mass spectrometry can provide confirmation of identity of target analytes, and will assist in the identification of unknown peaks should they be present in the chromatogram.

  15. Sensitive analytical methods for 22 relevant insecticides of 3 chemical families in honey by GC-MS/MS and LC-MS/MS.

    PubMed

    Paradis, Delphine; Bérail, Géraldine; Bonmatin, Jean-Marc; Belzunces, Luc P

    2014-01-01

    Several methods for analyzing pesticides in honey have been developed. However, they do not always reach the sufficiently low limits of quantification (LOQ) needed to quantify pesticides toxic to honey bees at low doses. To properly evaluate the toxicity of pesticides, LOQ have to reach at least 1 ng/g. In this context, we developed extraction and analytical methods for the simultaneous detection of 22 relevant insecticides belonging to three chemical families (neonicotinoids, pyrethroids, and pyrazoles) in honey. The insecticides were extracted with the QuEChERS method that consists in an extraction and a purification with mixtures of salts adapted to the matrix and the substances to be extracted. Analyses were performed by gas chromatography coupled with tandem mass spectrometry (GC-MS/MS) for the pyrazoles and the pyrethroids and by high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS) for the neonicotinoids and ethiprole. Calibration curves were built from various honey types fortified at different concentrations. Linear responses were obtained between 0.2 and 5 ng/g. Limits of detection (LOD) ranged between 0.07 and 0.2 ng/g, and LOQ ranged between 0.2 and 0.5 ng/g. The mean extraction yields ranged between 63 % and 139 % with RSD <25 %. A complete validation of the methods also examined recovery rates and specificity. These methods were applied to 90 honey samples collected during a 2009-2010 field study in two apiaries placed in different anthropic contexts.

  16. ESI-MS, ESI-MS/MS fingerprint and LC-ESI-MS analysis of proathocyanidins from Bursera simaruba Sarg bark.

    PubMed

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

    2009-12-01

    Direct flow injection/electrospray ionization/ion trap tandem mass spectrometry was used to investigate the presence of proanthocyanidins (PAs) in the methanolic extract of B. simaruba bark. Additionally, an LC-ESI-MS qualitative study was performed by using a monolithic stationary phase. The fragmentation pattern obtained evidenced the presence in B. simaruba bark of PAs belonging to the series of polymers of epicatechin, along with their glycosilated derivatives.

  17. Expedition 50 Soyuz MS-02 Landing

    NASA Image and Video Library

    2017-04-10

    nhq201704100001 (April 10, 2017) --- The Soyuz MS-02 spacecraft is seen as it lands with Expedition 50 Commander Shane Kimbrough of NASA and Flight Engineers Sergey Ryzhikov and Andrey Borisenko of Roscosmos near the town of Zhezkazgan, Kazakhstan on Monday, April 10, 2017 (Kazakh time). Kimbrough, Ryzhikov, and Borisenko are returning after 173 days in space where they served as members of the Expedition 49 and 50 crews onboard the International Space Station. Photo Credit: (NASA/Bill Ingalls)

  18. Expedition 50 Soyuz MS-02 Landing

    NASA Image and Video Library

    2017-04-10

    nhq201704100012 (April 10, 2017) --- The Soyuz MS-02 spacecraft is seen as it lands with Expedition 50 Commander Shane Kimbrough of NASA and Flight Engineers Sergey Ryzhikov and Andrey Borisenko of Roscosmos near the town of Zhezkazgan, Kazakhstan on Monday, April 10, 2017 (Kazakh time). Kimbrough, Ryzhikov, and Borisenko are returning after 173 days in space where they served as members of the Expedition 49 and 50 crews onboard the International Space Station. Photo Credit: (NASA/Bill Ingalls)

  19. Expedition 50 Soyuz MS-02 Landing

    NASA Image and Video Library

    2017-04-10

    nhq201704100017 (April 10, 2017) --- The Soyuz MS-02 spacecraft is seen as it lands with Expedition 50 Commander Shane Kimbrough of NASA and Flight Engineers Sergey Ryzhikov and Andrey Borisenko of Roscosmos near the town of Zhezkazgan, Kazakhstan on Monday, April 10, 2017 (Kazakh time). Kimbrough, Ryzhikov, and Borisenko are returning after 173 days in space where they served as members of the Expedition 49 and 50 crews onboard the International Space Station. Photo Credit: (NASA/Bill Ingalls)

  20. Expedition 50 Soyuz MS-02 Landing

    NASA Image and Video Library

    2017-04-10

    nhq201704100009 (April 10, 2017) --- The Soyuz MS-02 spacecraft is seen as it lands with Expedition 50 Commander Shane Kimbrough of NASA and Flight Engineers Sergey Ryzhikov and Andrey Borisenko of Roscosmos near the town of Zhezkazgan, Kazakhstan on Monday, April 10, 2017 (Kazakh time). Kimbrough, Ryzhikov, and Borisenko are returning after 173 days in space where they served as members of the Expedition 49 and 50 crews onboard the International Space Station. Photo Credit: (NASA/Bill Ingalls)

  1. Expedition 50 Soyuz MS-02 Landing

    NASA Image and Video Library

    2017-04-10

    nhq201704100020 (April 10, 2017) --- The Soyuz MS-02 spacecraft is seen as it lands with Expedition 50 Commander Shane Kimbrough of NASA and Flight Engineers Sergey Ryzhikov and Andrey Borisenko of Roscosmos near the town of Zhezkazgan, Kazakhstan on Monday, April 10, 2017 (Kazakh time). Kimbrough, Ryzhikov, and Borisenko are returning after 173 days in space where they served as members of the Expedition 49 and 50 crews onboard the International Space Station. Photo Credit: (NASA/Bill Ingalls)

  2. Expedition 50 Soyuz MS-02 Landing

    NASA Image and Video Library

    2017-04-10

    nhq201704100019 (April 10, 2017) --- The Soyuz MS-02 spacecraft is seen as it lands with Expedition 50 Commander Shane Kimbrough of NASA and Flight Engineers Sergey Ryzhikov and Andrey Borisenko of Roscosmos near the town of Zhezkazgan, Kazakhstan on Monday, April 10, 2017 (Kazakh time). Kimbrough, Ryzhikov, and Borisenko are returning after 173 days in space where they served as members of the Expedition 49 and 50 crews onboard the International Space Station. Photo Credit: (NASA/Bill Ingalls)

  3. Expedition 50 Soyuz MS-02 Landing

    NASA Image and Video Library

    2017-04-10

    nhq201704100006 (April 10, 2017) --- The Soyuz MS-02 spacecraft is seen as it lands with Expedition 50 Commander Shane Kimbrough of NASA and Flight Engineers Sergey Ryzhikov and Andrey Borisenko of Roscosmos near the town of Zhezkazgan, Kazakhstan on Monday, April 10, 2017 (Kazakh time). Kimbrough, Ryzhikov, and Borisenko are returning after 173 days in space where they served as members of the Expedition 49 and 50 crews onboard the International Space Station. Photo Credit: (NASA/Bill Ingalls)

  4. Expedition 50 Soyuz MS-02 Landing

    NASA Image and Video Library

    2017-04-10

    nhq201704100011 (April 10, 2017) --- The Soyuz MS-02 spacecraft is seen as it lands with Expedition 50 Commander Shane Kimbrough of NASA and Flight Engineers Sergey Ryzhikov and Andrey Borisenko of Roscosmos near the town of Zhezkazgan, Kazakhstan on Monday, April 10, 2017 (Kazakh time). Kimbrough, Ryzhikov, and Borisenko are returning after 173 days in space where they served as members of the Expedition 49 and 50 crews onboard the International Space Station. Photo Credit: (NASA/Bill Ingalls)

  5. Expedition 50 Soyuz MS-02 Landing

    NASA Image and Video Library

    2017-04-10

    nhq201704100007 (April 10, 2017) --- The Soyuz MS-02 spacecraft is seen as it lands with Expedition 50 Commander Shane Kimbrough of NASA and Flight Engineers Sergey Ryzhikov and Andrey Borisenko of Roscosmos near the town of Zhezkazgan, Kazakhstan on Monday, April 10, 2017 (Kazakh time). Kimbrough, Ryzhikov, and Borisenko are returning after 173 days in space where they served as members of the Expedition 49 and 50 crews onboard the International Space Station. Photo Credit: (NASA/Bill Ingalls)

  6. Expedition 50 Soyuz MS-02 Landing

    NASA Image and Video Library

    2017-04-10

    nhq201704100008 (April 10, 2017) --- The Soyuz MS-02 spacecraft is seen as it lands with Expedition 50 Commander Shane Kimbrough of NASA and Flight Engineers Sergey Ryzhikov and Andrey Borisenko of Roscosmos near the town of Zhezkazgan, Kazakhstan on Monday, April 10, 2017 (Kazakh time). Kimbrough, Ryzhikov, and Borisenko are returning after 173 days in space where they served as members of the Expedition 49 and 50 crews onboard the International Space Station. Photo Credit: (NASA/Bill Ingalls)

  7. Expedition 50 Soyuz MS-02 Landing

    NASA Image and Video Library

    2017-04-10

    nhq201704100013 (April 10, 2017) --- The Soyuz MS-02 spacecraft is seen as it lands with Expedition 50 Commander Shane Kimbrough of NASA and Flight Engineers Sergey Ryzhikov and Andrey Borisenko of Roscosmos near the town of Zhezkazgan, Kazakhstan on Monday, April 10, 2017 (Kazakh time). Kimbrough, Ryzhikov, and Borisenko are returning after 173 days in space where they served as members of the Expedition 49 and 50 crews onboard the International Space Station. Photo Credit: (NASA/Bill Ingalls)

  8. Expedition 50 Soyuz MS-02 Landing

    NASA Image and Video Library

    2017-04-10

    nhq201704100018 (April 10, 2017) --- The Soyuz MS-02 spacecraft is seen as it lands with Expedition 50 Commander Shane Kimbrough of NASA and Flight Engineers Sergey Ryzhikov and Andrey Borisenko of Roscosmos near the town of Zhezkazgan, Kazakhstan on Monday, April 10, 2017 (Kazakh time). Kimbrough, Ryzhikov, and Borisenko are returning after 173 days in space where they served as members of the Expedition 49 and 50 crews onboard the International Space Station. Photo Credit: (NASA/Bill Ingalls

  9. Petroleomics by EASI(+/-) FT-ICR MS.

    PubMed

    Corilo, Yuri E; Vaz, Boniek G; Simas, Rosineide C; Nascimento, Heliara D Lopes; Klitzke, Clécio F; Pereira, Rosana C L; Bastos, Wagner L; Santos Neto, Eugênio V; Rodgers, Ryan P; Eberlin, Marcos N

    2010-05-15

    An ambient ionization/desorption technique, namely, easy ambient sonic-spray ionization mass spectrometry (EASI), has been applied to crude oil samples. From a single droplet of the sample placed on an inert surface, EASI(+/-) is shown to promote efficient desorption and ionization of a myriad of polar components via the action of its cloud of very minute supersonic bipolar charged droplets. The gaseous [M + H](+) and [M - H](-) ions concurrently formed by EASI(+/-) were analyzed by Fourier transform mass spectrometry (FT-ICR MS), and a total of approximately 6000 acidic and basic components have been attributed. EASI(+/-) FT-ICR MS of crude oils is show to be almost as fast as ESI(+)/ESI(-) FT-ICR MS, providing similar compositional information of polar components and spectral quality comparable to that of a commercial nonochip-based robotic ESI device. EASI(+/-) requires no sample workup thus eliminating risks of contamination during sample manipulation and memory effects because of carry over in pumping ESI lines. More importantly, EASI(+/-) is a voltage-free ionization technique therefore eliminating risks of redox processes or duality of ionization mechanisms that can be observed in voltage-assisted processes. Data visualization via typical petroleomic plots confirms the similarity of the compositional information provided by EASI(+/-) compared to ESI(+)/ESI(-). The ambient EASI(+/-) FT-ICR MS method requires no voltage switching in changing the ion polarity mode, offering a workup, heating and voltage-free protocol for petroleomic studies performed at open atmosphere directly on the undisturbed crude oil sample.

  10. Familiar Face Detection in 180ms

    PubMed Central

    Visconti di Oleggio Castello, Matteo; Gobbini, M. Ida

    2015-01-01

    The visual system is tuned for rapid detection of faces, with the fastest choice saccade to a face at 100ms. Familiar faces have a more robust representation than do unfamiliar faces, and are detected faster in the absence of awareness and with reduced attentional resources. Faces of family and close friends become familiar over a protracted period involving learning the unique visual appearance, including a view-invariant representation, as well as person knowledge. We investigated the effect of personal familiarity on the earliest stages of face processing by using a saccadic-choice task to measure how fast familiar face detection can happen. Subjects made correct and reliable saccades to familiar faces when unfamiliar faces were distractors at 180ms—very rapid saccades that are 30 to 70ms earlier than the earliest evoked potential modulated by familiarity. By contrast, accuracy of saccades to unfamiliar faces with familiar faces as distractors did not exceed chance. Saccades to faces with object distractors were even faster (110 to 120 ms) and equivalent for familiar and unfamiliar faces, indicating that familiarity does not affect ultra-rapid saccades. We propose that detectors of diagnostic facial features for familiar faces develop in visual cortices through learning and allow rapid detection that precedes explicit recognition of identity. PMID:26305788

  11. Detection of gamma-hydroxybutyrate in hair: validation of GC-MS and LC-MS/MS methods and application to a real case.

    PubMed

    Bertol, Elisabetta; Argo, Antonina; Procaccianti, Paolo; Vaiano, Fabio; Di Milia, Maria Grazia; Furlanetto, Sandra; Mari, Francesco

    2012-11-01

    A gas chromatography-mass spectrometry (GC-MS) and a liquid chromatography tandem mass spectrometry (LC-MS/MS) method were validated for quantifying endogenous and exogenous hair concentrations of gamma-hydroxybutyrate (GHB). The GC-MS method is based on overnight extraction of 25 mg hair in NaOH at 56 °C, liquid/liquid extraction in ethylacetate and trimethylsylil derivatization; analysis is by electron ionization and single ion monitoring of three ions. The LC-MS/MS method entails a rapid digestion of 25 mg hair with NaOH at 75 °C for 40 min, liquid/liquid extraction in ethylacetate and reconstitution of the extract in the LC mobile phase; negative ion electrospray ionization and multiple reaction monitoring (MRM) analysis are employed for the LC-MS/MS detection. In both cases, GHB-d6 is used as an internal standard. The endogenous amount in "blank" hair are estimated by the standard addition method. Limits of detection are 0.4 and 0.5 ng/mg for GC-MS and LC-MS/MS respectively, while the limit of quantification (LOQ) is 0.6 ng/mg for both methods; the GC-MS method proved to be linear in the range 1-50 ng/mg whereas linearity was demonstrated from 0.6 to 50 ng/mg for the LC-MS/MS; imprecision and inaccuracy were always lower than 23% for quality controls samples. The two methods were applied to a real case of a man addicted to GHB; the drug concentration in segments from 17 cm hair strand well correlated with self-reported use of GHB in different periods of his life. Performances of the two methods were similar.

  12. EMS & the DEA.

    PubMed

    Beeson, Jeff; Ayres, Chris

    2010-01-01

    It's clear that EMS medical directors and management staff must be vigilant in their oversight of implementation, administration and monitoring of controlled substances within their agencies to best serve the public and avoid running afoul of investigation and incurring significant penalties. Those potentially affected by the need for individual registrations of both emergency vehicles and central inventory systems should carefully monitor upcoming developments in the interpretation od DEA regulations.

  13. siMS Score: Simple Method for Quantifying Metabolic Syndrome

    PubMed Central

    Soldatovic, Ivan; Vukovic, Rade; Culafic, Djordje; Gajic, Milan; Dimitrijevic-Sreckovic, Vesna

    2016-01-01

    Objective To evaluate siMS score and siMS risk score, novel continuous metabolic syndrome scores as methods for quantification of metabolic status and risk. Materials and Methods Developed siMS score was calculated using formula: siMS score = 2*Waist/Height + Gly/5.6 + Tg/1.7 + TAsystolic/130—HDL/1.02 or 1.28 (for male or female subjects, respectively). siMS risk score was calculated using formula: siMS risk score = siMS score * age/45 or 50 (for male or female subjects, respectively) * family history of cardio/cerebro-vascular events (event = 1.2, no event = 1). A sample of 528 obese and non-obese participants was used to validate siMS score and siMS risk score. Scores calculated as sum of z-scores (each component of metabolic syndrome regressed with age and gender) and sum of scores derived from principal component analysis (PCA) were used for evaluation of siMS score. Variants were made by replacing glucose with HOMA in calculations. Framingham score was used for evaluation of siMS risk score. Results Correlation between siMS score with sum of z-scores and weighted sum of factors of PCA was high (r = 0.866 and r = 0.822, respectively). Correlation between siMS risk score and log transformed Framingham score was medium to high for age groups 18+,30+ and 35+ (0.835, 0.707 and 0.667, respectively). Conclusions siMS score and siMS risk score showed high correlation with more complex scores. Demonstrated accuracy together with superior simplicity and the ability to evaluate and follow-up individual patients makes siMS and siMS risk scores very convenient for use in clinical practice and research as well. PMID:26745635

  14. LC-MS-MS Method for Analysis of Opiates in Wastewater During Football Games II.

    PubMed

    Gul, Waseem; Stamper, Brandon; Godfrey, Murrell; Gul, Shahbaz W; ElSohly, Mahmoud A

    2016-06-01

    Continuing our previous studies analyzing drugs of abuse in municipal wastewater, a method was developed for the analysis of opiates in wastewater samples using liquid chromatography coupled with tandem mass spectrometry (LC-MS-MS). Eight opiate drugs and metabolites were analyzed including codeine, hydrocodone, hydromorphone, 6-monoacetylmorphine (6-MAM, the primary urinary metabolite of heroin), morphine, norhydrocodone (the primary urinary metabolite of hydrocodone), oxycodone and oxymorphone. These drugs were chosen because of their widespread abuse. Wastewater samples were collected at both the Oxford Waste Water Treatment Plant in Oxford, Mississippi (MS) and the University Wastewater Treatment Plant in University, MS. These wastewater samples were collected on weekends in which the Ole Miss Rebel football team held home games (Vaught-Hemingway Stadium, University, MS 38677). The collected samples were analyzed using a validated method and found to contain codeine, hydrocodone, hydromorphone, morphine, norhydrocodone, oxycodone and oxymorphone. None of the samples contained 6-MAM. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  15. Determination of 48 fragrance allergens in toys using GC with ion trap MS/MS.

    PubMed

    Lv, Qing; Zhang, Qing; Li, Wentao; Li, Haiyu; Li, Pi; Ma, Qiang; Meng, Xianshuang; Qi, Meiling; Bai, Hua

    2013-11-01

    This paper presents a method for the simultaneous determination of 48 fragrance allergens in four types of toys (plastic toys, play clays, plush toys, and paper toys) based on GC with ion trap MS/MS. Compared with single-stage MS, MS/MS is superior in terms of the qualification and quantification of a large range of compounds in complicated matrices. Procedures for extraction and purification were optimized for each toy type. The method proved to be linear over a wide range of concentrations for all analytes with correlation coefficients between 0.9768 and 0.9999. Validation parameters, namely, LODs and LOQs, ranged from 0.005-5.0 and from 0.02-20 mg/kg, respectively. Average recoveries of target compounds (spiked at three concentration levels) were in the range of 79.5-109.1%. Intraday and interday repeatabilities of the proposed method varied from 0.7-10.5% and from 3.1-13.4%, respectively. The proposed method was used to monitor fragrance allergens in commercial toy products. Our findings indicate that this method is an accurate and effective technique for analyzing fragrance allergens in materials composed of complex components. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. LC-MS-MS Method for Stimulants in Wastewater During Football Games.

    PubMed

    Gul, Waseem; Stamper, Brandon J; Godfrey, Murrell; ElSohly, Mahmoud A

    2016-03-01

    A method was developed for the analysis of amphetamines and cocaine (Coc) in wastewater samples using liquid chromatography coupled with tandem mass spectrometry (LC-MS-MS). Seven stimulant-type drugs and metabolites were analyzed. These drugs included amphetamine (Amp), methamphetamine (Meth), methylenedioxyamphetamine (MDA), methylenedioxymethamphetamine (MDMA), methylenedioxyethylamphetamine (MDEA), Coc and benzoylecgonine (BE, the major metabolite of Coc). These drugs were chosen because of their widespread use. Wastewater samples were collected at both the Oxford Waste Water Treatment Plant in Oxford, Mississippi (MS) and the University Wastewater Treatment Plant in University, MS. Samples were collected on weekends in which the Ole Miss Rebel football team held home games (Vaught-Hemingway Stadium, University, MS 38677). The collected samples were analyzed using a validated method and found to contain Amp, Meth, MDMA, Coc and BE. The concentrations of Amp and BE significantly rose in the university wastewater during football games. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  17. SWATH Mass Spectrometry Performance Using Extended Peptide MS/MS Assay Libraries*

    PubMed Central

    Wu, Jemma X.; Song, Xiaomin; Pascovici, Dana; Zaw, Thiri; Care, Natasha; Krisp, Christoph; Molloy, Mark P.

    2016-01-01

    The use of data-independent acquisition methods such as SWATH for mass spectrometry based proteomics is usually performed with peptide MS/MS assay libraries which enable identification and quantitation of peptide peak areas. Reference assay libraries can be generated locally through information dependent acquisition, or obtained from community data repositories for commonly studied organisms. However, there have been no studies performed to systematically evaluate how locally generated or repository-based assay libraries affect SWATH performance for proteomic studies. To undertake this analysis, we developed a software workflow, SwathXtend, which generates extended peptide assay libraries by integration with a local seed library and delivers statistical analysis of SWATH-quantitative comparisons. We designed test samples using peptides from a yeast extract spiked into peptides from human K562 cell lysates at three different ratios to simulate protein abundance change comparisons. SWATH-MS performance was assessed using local and external assay libraries of varying complexities and proteome compositions. These experiments demonstrated that local seed libraries integrated with external assay libraries achieve better performance than local assay libraries alone, in terms of the number of identified peptides and proteins and the specificity to detect differentially abundant proteins. Our findings show that the performance of extended assay libraries is influenced by the MS/MS feature similarity of the seed and external libraries, while statistical analysis using multiple testing corrections increases the statistical rigor needed when searching against large extended assay libraries. PMID:27161445

  18. Rapid quantification of glutaminase 2 (GLS2)-related metabolites by HILIC-MS/MS.

    PubMed

    Chen, Guan-Yuan; Chao, Hsi-Chun; Liao, Hsiao-Wei; Tsai, I-Lin; Kuo, Ching-Hua

    2017-10-06

    Glutamine, glutamate and glutathione are key modulators of excessive oxidative stress in tumor cells. In this study, we developed a rapid and accurate HILIC-MS/MS method to simultaneously determine concentrations of cellular glutamine, glutamate and glutathione. A bared silica HILIC column was employed to analyze these polar metabolites. The LC-MS parameters were optimized to achieve high sensitivity and selectivity. The analysis can be completed within 4 min under optimal conditions. The method was validated in terms of accuracy, precision, and linearity. Intra-day (n = 9) precision was within 2.68-6.24% among QCs. Inter-day precision (n = 3) was below 12.4%. The method accuracy was evaluated by the recovery test, and the accuracy for three analytes were between 91.6 and 110%. The developed method was applied to study antioxidant function of GLS2 in non-small cell lung cancer cells. Changes in concentrations of glutamine, glutamate and glutathione revealed that the overexpression of GLS2 could effectively decrease oxidative stress. In summary, this study developed a rapid HILIC-MS/MS method for quantification of GLS2-related metabolites that could facilitate elucidation of the role of GLS2 in tumor development. Copyright © 2017. Published by Elsevier Inc.

  19. LC-MS/MS method for the characterization of the forced degradation products of Entecavir.

    PubMed

    Ramesh, Thippani; Rao, Pothuraju Nageswara; Rao, Ramisetti Nageswara

    2014-02-01

    A rapid, specific, and reliable isocratic LC-MS/MS method has been developed and validated for the identification and characterization of the stressed degradation products of Entecavir (ETV). ETV, an antiviral drug, was subjected to hydrolysis (acidic, alkaline, and neutral), oxidation, photolysis and thermal stress, as per the international conference on harmonization specified conditions. The drug showed extensive degradation under oxidative and acid hydrolysis stress conditions. However, it was stable to thermal, acidic, neutral, and photolysis stress conditions. A total of five degradation products were observed and the chromatographic separation of the drug and its degradation products were achieved on a Waters Symmetry C18 (250 mm × 4.6 mm, id, 5 μm) column using 20 mM ammonium acetate (pH 3)/acetonitrile (50:50, v/v) as a mobile phase. The degradation products were characterized by LC-MS/MS and its fragmentation pathways were proposed. The LC-MS method was validated with respect to specificity, linearity, accuracy, and precision. No previous reports were found in the literature regarding the degradation behavior of ETV.

  20. Validation of an HPLC-MS/MS and wipe procedure for mitomycin C contamination.

    PubMed

    B'Hymer, Clayton; Connor, Thomas; Stinson, Derek; Pretty, Jack

    2015-04-01

    A high-performance liquid chromatography-tandem mass spectrometric (HPLC-MS/MS) method was developed for the determination of mitomycin C, an anticancer drug, from contamination on various surfaces. Mitomycin C is often used in various forms of intraperitoneal chemotherapy, and operating room healthcare worker exposure to this drug is possible. The surface testing method consisted of a wiping procedure utilizing a solution of 20/45/35 (v/v/v) of acetonitrile-isopropanol-water made 0.01 M in ammonium citrate (apparent pH 7.0). The wipe solutions were analyzed by means of HPLC-MS/MS using a reversed-phase gradient system and electrospray ionization in positive ion mode with a triple-quadrupole MS detector. Accuracy and precision of this method were demonstrated by a series of recovery studies of both spiked solutions and extracted wipes from various surfaces (stainless steel, vinyl and Formica(®)) spiked with known levels of mitomycin C. Recoveries of spiked solutions containing the analyte demonstrate mean recoveries (accuracy) ranged from 93 to 105%. Precision as measured by the relative standard deviation (% RSD) of multiple samples (n= 10) at each concentration level demonstrated values of 7.5% or less. The recoveries from spiked surfaces varied from 30 to 99%. The limit of detection for this methodology is ∼2 ng/100 cm(2) equivalent surface area, and the limit of quantitation is ∼6 ng/100 cm(2).

  1. Antidepressants detection and quantification in whole blood samples by GC-MS/MS, for forensic purposes.

    PubMed

    Truta, Liliana; Castro, André L; Tarelho, Sónia; Costa, Pedro; Sales, M Goreti F; Teixeira, Helena M

    2016-09-05

    Depression is among the most prevalent psychiatric disorders of our society, leading to an increase in antidepressant drug consumption that needs to be accurately determined in whole blood samples in Forensic Toxicology Laboratories. For this purpose, this work presents a new gas chromatography tandem mass spectrometry (GC-MS/MS) method targeting the simultaneous and rapid determination of 14 common Antidepressants in whole blood: 13 Antidepressants (amitriptyline, citalopram, clomipramine, dothiepin, fluoxetine, imipramine, mianserin, mirtazapine, nortryptiline, paroxetine, sertraline, trimipramine and venlafaxine) and 1 Metabolite (N-desmethylclomipramine). Solid-phase extraction was used prior to chromatographic separation. Chromatographic and MS/MS parameters were selected to improve sensitivity, peak resolution and unequivocal identification of the eluted analyte. The detection was performed on a triple quadrupole tandem MS in selected ion monitoring (SIM) mode in tandem, using electronic impact ionization. Clomipramine-D3 and trimipramine-D3 were used as deutered internal standards. The validation parameters included linearity, limits of detection, lower limit of quantification, selectivity/specificity, extraction efficiency, carry-over, precision and robustness, and followed internationally accepted guidelines. Limits of quantification and detection were lower than therapeutic and sub-therapeutic concentration ranges. Overall, the method offered good selectivity, robustness and quick response (<16min) for typical concentration ranges, both for therapeutic and lethal levels. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Development of LC/MS/MS Methods for Implementation in US ...

    EPA Pesticide Factsheets

    Well-characterized and standardized methods are the foundation upon which monitoring of regulated and unregulated contaminants in drinking water are based. To obtain reliable, high quality data for trace analysis of contaminants, these methods must be rugged, selective and sensitive as well as accurate and precise. The EPA’s Office of Ground Water and Drinking Water collects nationwide occurrence data on contaminants in drinking water using the Unregulated Contaminant Monitoring Regulations (UCMRs) promulgated under the Safe Drinking Water Act. The unregulated contaminants, which are potential candidates for future regulation, may be selected from the Drinking Water Contaminant Candidate List (CCL), or may be contaminants of emerging concern. Standardized methods are needed that will produce data of sufficient quality for accurate monitoring of chemicals on the CCL, or chemicals of emerging concern in drinking water, under the UCMR program. Better monitoring data will assist EPA in making regulatory decisions and help safeguard the nation’s drinking water supply from harmful drinking water contaminants. Over the past decade, 12 drinking water methods have been developed using LC/MS or LC/MS/MS and 5 of these methods have been or will be used in UCMRs 1-4 to gather nationwide occurrence data on drinking water contaminants. The primary focus of this presentation will be on the application of LC/MS/MS techniques to the analysis of CCL or emerging contaminants

  3. Comparison of Proteins in Whole Blood and Dried Blood Spot Samples by LC/MS/MS

    NASA Astrophysics Data System (ADS)

    Chambers, Andrew G.; Percy, Andrew J.; Hardie, Darryl B.; Borchers, Christoph H.

    2013-09-01

    Dried blood spot (DBS) sampling methods are desirable for population-wide biomarker screening programs because of their ease of collection, transportation, and storage. Immunoassays are traditionally used to quantify endogenous proteins in these samples but require a separate assay for each protein. Recently, targeted mass spectrometry (MS) has been proposed for generating highly-multiplexed assays for biomarker proteins in DBS samples. In this work, we report the first comparison of proteins in whole blood and DBS samples using an untargeted MS approach. The average number of proteins identified in undepleted whole blood and DBS samples by liquid chromatography (LC)/MS/MS was 223 and 253, respectively. Protein identification repeatability was between 77 %-92 % within replicates and the majority of these repeated proteins (70 %) were observed in both sample formats. Proteins exclusively identified in the liquid or dried fluid spot format were unbiased based on their molecular weight, isoelectric point, aliphatic index, and grand average hydrophobicity. In addition, we extended this comparison to include proteins in matching plasma and serum samples with their dried fluid spot equivalents, dried plasma spot (DPS), and dried serum spot (DSS). This work begins to define the accessibility of endogenous proteins in dried fluid spot samples for analysis by MS and is useful in evaluating the scope of this new approach.

  4. SWATH Mass Spectrometry Performance Using Extended Peptide MS/MS Assay Libraries.

    PubMed

    Wu, Jemma X; Song, Xiaomin; Pascovici, Dana; Zaw, Thiri; Care, Natasha; Krisp, Christoph; Molloy, Mark P

    2016-07-01

    The use of data-independent acquisition methods such as SWATH for mass spectrometry based proteomics is usually performed with peptide MS/MS assay libraries which enable identification and quantitation of peptide peak areas. Reference assay libraries can be generated locally through information dependent acquisition, or obtained from community data repositories for commonly studied organisms. However, there have been no studies performed to systematically evaluate how locally generated or repository-based assay libraries affect SWATH performance for proteomic studies. To undertake this analysis, we developed a software workflow, SwathXtend, which generates extended peptide assay libraries by integration with a local seed library and delivers statistical analysis of SWATH-quantitative comparisons. We designed test samples using peptides from a yeast extract spiked into peptides from human K562 cell lysates at three different ratios to simulate protein abundance change comparisons. SWATH-MS performance was assessed using local and external assay libraries of varying complexities and proteome compositions. These experiments demonstrated that local seed libraries integrated with external assay libraries achieve better performance than local assay libraries alone, in terms of the number of identified peptides and proteins and the specificity to detect differentially abundant proteins. Our findings show that the performance of extended assay libraries is influenced by the MS/MS feature similarity of the seed and external libraries, while statistical analysis using multiple testing corrections increases the statistical rigor needed when searching against large extended assay libraries.

  5. Vitamins, Minerals, and Herbs in MS: An Introduction

    MedlinePlus

    Vitamins, Minerals & Herbs in MS AN INTRODUCTION Eric (front cover), diagnosed in 1951. Vitamins, Minerals & Herbs in MS AN INTRODUCTION BY: ALLEN ... This booklet focuses on the use of popular vitamins, minerals and herbs by people living with multiple ...

  6. NH Small MS4 General Permit | Stormwater Permits | NPDES ...

    EPA Pesticide Factsheets

    2017-04-13

    The 2017 New Hampshire Small MS4 General Permit was issued on January 18, 2017. The final permit reflects modifications to the 2013 Draft Small MS4 General Permit and the 2015 Renoticed permit sections.

  7. 8. OLD AMORYBIGBEE BRIDGE MISSISSIPPI, MONROE CO., AMORY MS. 6, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. OLD AMORY-BIGBEE BRIDGE MISSISSIPPI, MONROE CO., AMORY MS. 6, 1.5 mi. NW of Amory. Road 2.5 mi. N of Bull Mtn. Cr. Copy of 8x10 photo taken at completion of work, 1899. Swing bridge is fully open. View from S. Credit to Evans Memorial Library, Aberdeen, Ms. Sarcone Photography, Columbus, Ms. September 1978. - Bridges of the Upper Tombigbee River Valley, Columbus, Lowndes County, MS

  8. 7. OLD AMORYBIGBEE BRIDGE MISSISSIPPI, MONROE CO., AMORY MS. 6, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. OLD AMORY-BIGBEE BRIDGE MISSISSIPPI, MONROE CO., AMORY MS. 6, 1.5 mi. NW of Amory. Road 2.5 mi. N of Bull Mtn. Cr. Copy of 8x10 photo taken at completion of work, 1899. Swing bridge is fully open. View from S. Credit to Evans Memorial Library, Aberdeen, Ms. Sarcone Photography, Columbus, Ms. September 1978. - Bridges of the Upper Tombigbee River Valley, Columbus, Lowndes County, MS

  9. Clinically meaningful performance benchmarks in MS

    PubMed Central

    Motl, Robert W.; Scagnelli, John; Pula, John H.; Sosnoff, Jacob J.; Cadavid, Diego

    2013-01-01

    Objective: Identify and validate clinically meaningful Timed 25-Foot Walk (T25FW) performance benchmarks in individuals living with multiple sclerosis (MS). Methods: Cross-sectional study of 159 MS patients first identified candidate T25FW benchmarks. To characterize the clinical meaningfulness of T25FW benchmarks, we ascertained their relationships to real-life anchors, functional independence, and physiologic measurements of gait and disease progression. Candidate T25FW benchmarks were then prospectively validated in 95 subjects using 13 measures of ambulation and cognition, patient-reported outcomes, and optical coherence tomography. Results: T25FW of 6 to 7.99 seconds was associated with a change in occupation due to MS, occupational disability, walking with a cane, and needing “some help” with instrumental activities of daily living; T25FW ≥8 seconds was associated with collecting Supplemental Security Income and government health care, walking with a walker, and inability to do instrumental activities of daily living. During prospective benchmark validation, we trichotomized data by T25FW benchmarks (<6 seconds, 6–7.99 seconds, and ≥8 seconds) and found group main effects on 12 of 13 objective and subjective measures (p < 0.05). Conclusions: Using a cross-sectional design, we identified 2 clinically meaningful T25FW benchmarks of ≥6 seconds (6–7.99) and ≥8 seconds. Longitudinal and larger studies are needed to confirm the clinical utility and relevance of these proposed T25FW benchmarks and to parse out whether there are additional benchmarks in the lower (<6 seconds) and higher (>10 seconds) ranges of performance. PMID:24174581

  10. Expedition 50 Soyuz MS-02 Landing

    NASA Image and Video Library

    2017-04-10

    nhq201704100048 (April 10, 2017) --- NASA astronaut Shane Kimbrough arrives at the Karaganda Airport in Kazakhstan airport after he, Russian cosmonaut Sergey Ryzhikov of Roscosmos and, Russian cosmonaut Andrey Borisenko of Roscosmos landed in their Soyuz MS-02 spacecraft in a remote area near the town of Zhezkazgan, Kazakhstan on Monday, April 10, 2017 (Kazakh time). Kimbrough, Ryzhikov, and Borisenko are returning after 173 days in space where they served as members of the Expedition 49 and 50 crews onboard the International Space Station. Photo Credit: (NASA/Bill Ingalls)

  11. Expedition 50 Soyuz MS-02 Landing

    NASA Image and Video Library

    2017-04-10

    nhq201704100021 (April 10, 2017) --- Russian Search and Rescue teams arrive at the Soyuz MS-02 spacecraft shortly after it landed with Expedition 50 Commander Shane Kimbrough of NASA and Flight Engineers Sergey Ryzhikov and Andrey Borisenko of Roscosmos near the town of Zhezkazgan, Kazakhstan on Monday, April 10, 2017 (Kazakh time). Kimbrough, Ryzhikov, and Borisenko are returning after 173 days in space where they served as members of the Expedition 49 and 50 crews onboard the International Space Station. Photo Credit: (NASA/Bill Ingalls)

  12. Expedition 50 Soyuz MS-02 Landing

    NASA Image and Video Library

    2017-04-10

    nhq201704100016 (April 10, 2017) --- Russian Search and Rescue teams chase the Soyuz MS-02 spacecraft as it lands with Expedition 50 Commander Shane Kimbrough of NASA and Flight Engineers Sergey Ryzhikov and Andrey Borisenko of Roscosmos near the town of Zhezkazgan, Kazakhstan on Monday, April 10, 2017 (Kazakh time). Kimbrough, Ryzhikov, and Borisenko are returning after 173 days in space where they served as members of the Expedition 49 and 50 crews onboard the International Space Station. Photo Credit: (NASA/Bill Ingalls)

  13. Expedition 50 Soyuz MS-02 Landing

    NASA Image and Video Library

    2017-04-10

    nhq201704100015 (April 10, 2017) --- Russian Search and Rescue teams chase the Soyuz MS-02 spacecraft as it lands with Expedition 50 Commander Shane Kimbrough of NASA and Flight Engineers Sergey Ryzhikov and Andrey Borisenko of Roscosmos near the town of Zhezkazgan, Kazakhstan on Monday, April 10, 2017 (Kazakh time). Kimbrough, Ryzhikov, and Borisenko are returning after 173 days in space where they served as members of the Expedition 49 and 50 crews onboard the International Space Station. Photo Credit: (NASA/Bill Ingalls)

  14. Expedition 50 Soyuz MS-02 Landing

    NASA Image and Video Library

    2017-04-10

    nhq201704100014 (April 10, 2017) --- Russian Search and Rescue teams chase the Soyuz MS-02 spacecraft as it lands with Expedition 50 Commander Shane Kimbrough of NASA and Flight Engineers Sergey Ryzhikov and Andrey Borisenko of Roscosmos near the town of Zhezkazgan, Kazakhstan on Monday, April 10, 2017 (Kazakh time). Kimbrough, Ryzhikov, and Borisenko are returning after 173 days in space where they served as members of the Expedition 49 and 50 crews onboard the International Space Station. Photo Credit: (NASA/Bill Ingalls)

  15. Expedition 50 Soyuz MS-02 Landing

    NASA Image and Video Library

    2017-04-10

    nhq201704100043 (April 10, 2017) --- American and Russian support personnel work around the Soyuz MS-02 spacecraft shortly after it landed with Expedition 50 Commander Shane Kimbrough of NASA and Flight Engineers Sergey Ryzhikov and Andrey Borisenko of Roscosmos near the town of Zhezkazgan, Kazakhstan on Monday, April 10, 2017 (Kazakh time). Kimbrough, Ryzhikov, and Borisenko are returning after 173 days in space where they served as members of the Expedition 49 and 50 crews onboard the International Space Station. Photo Credit: (NASA/Bill Ingalls)

  16. Expedition 50 Soyuz MS-02 Landing

    NASA Image and Video Library

    2017-04-10

    nhq201704100045 (April 10, 2017) --- NASA astronaut Shane Kimbrough, left, is helped into an awaiting Russian MI-8 helicopter by NASA flight doctor Blake Chamberlain shortly after he, Russian cosmonaut Sergey Ryzhikov of Roscosmos, and Russian cosmonaut Andrey Borisenko of Roscosmos landed in their Soyuz MS-02 spacecraft in a remote area near the town of Zhezkazgan, Kazakhstan on Monday, April 10, 2017 (Kazakh time). Kimbrough, Ryzhikov, and Borisenko are returning after 173 days in space where they served as members of the Expedition 49 and 50 crews onboard the International Space Station. Photo Credit: (NASA/Bill Ingalls)

  17. Expedition 50 Soyuz MS-02 Landing

    NASA Image and Video Library

    2017-04-10

    nhq201704100035 (April 10, 2017) --- Russian cosmonaut Andrey Borisenko of Roscosmos is carried into a medical tent shortly after he, NASA astronaut Shane Kimbrough, and Russian cosmonaut Sergey Ryzhikov of Roscosmos landed in their Soyuz MS-02 spacecraft in a remote area near the town of Zhezkazgan, Kazakhstan on Monday, April 10, 2017 (Kazakh time). Kimbrough, Ryzhikov, and Borisenko are returning after 173 days in space where they served as members of the Expedition 49 and 50 crews onboard the International Space Station. Photo Credit: (NASA/Bill Ingalls)

  18. Expedition 50 Soyuz MS-02 Landing

    NASA Image and Video Library

    2017-04-10

    nhq201704100046 (April 10, 2017) --- NASA astronaut Shane Kimbrough, seated right, is seen inside a Russian MI-8 helicopter after he, Russian cosmonaut Sergey Ryzhikov of Roscosmos, and Russian cosmonaut Andrey Borisenko of Roscosmos landed in their Soyuz MS-02 spacecraft in a remote area near the town of Zhezkazgan, Kazakhstan on Monday, April 10, 2017 (Kazakh time). Kimbrough, Ryzhikov, and Borisenko are returning after 173 days in space where they served as members of the Expedition 49 and 50 crews onboard the International Space Station. Photo Credit: (NASA/Bill Ingalls)

  19. Expedition 50 Soyuz MS-02 Landing

    NASA Image and Video Library

    2017-04-10

    nhq201704100036 (April 10, 2017) --- Russian support personnel work around the Soyuz MS-02 spacecraft shortly after it landed with Expedition 50 Commander Shane Kimbrough of NASA and Flight Engineers Sergey Ryzhikov and Andrey Borisenko of Roscosmos near the town of Zhezkazgan, Kazakhstan on Monday, April 10, 2017 (Kazakh time). Kimbrough, Ryzhikov, and Borisenko are returning after 173 days in space where they served as members of the Expedition 49 and 50 crews onboard the International Space Station. Photo Credit: (NASA/Bill Ingalls)

  20. Expedition 50 Soyuz MS-02 Landing

    NASA Image and Video Library

    2017-04-10

    nhq201704100005 (April 10, 2017) --- Russian cosmonaut Andrey Borisenko of Roscosmos rests in a chair outside the Soyuz MS-02 spacecraft just minutes after he, NASA astronaut Shane Kimbrough, and Russian cosmonaut Sergey Ryzhikov of Roscosmos landed in a remote area near the town of Zhezkazgan, Kazakhstan on Monday, April 10, 2017 (Kazakh time). Kimbrough, Ryzhikov, and Borisenko are returning after 173 days in space where they served as members of the Expedition 49 and 50 crews onboard the International Space Station. Photo Credit: (NASA/Bill Ingalls)

  1. Expedition 50 Soyuz MS-02 Landing

    NASA Image and Video Library

    2017-04-10

    nhq201704100042 (April 10, 2017) --- Russian MI-8 helicopters are seen at the Soyuz MS-02 landing site after the spacecraft landed with Expedition 50 Commander Shane Kimbrough of NASA and Flight Engineers Sergey Ryzhikov and Andrey Borisenko of Roscosmos near the town of Zhezkazgan, Kazakhstan on Monday, April 10, 2017 (Kazakh time). Kimbrough, Ryzhikov, and Borisenko are returning after 173 days in space where they served as members of the Expedition 49 and 50 crews onboard the International Space Station. Photo Credit: (NASA/Bill Ingalls)

  2. Expedition 50 Soyuz MS-02 Landing

    NASA Image and Video Library

    2017-04-10

    nhq201704100044 (April 10, 2017) --- Russian support personnel work around the Soyuz MS-02 spacecraft shortly after it landed with Expedition 50 Commander Shane Kimbrough of NASA and Flight Engineers Sergey Ryzhikov and Andrey Borisenko of Roscosmos near the town of Zhezkazgan, Kazakhstan on Monday, April 10, 2017 (Kazakh time). Kimbrough, Ryzhikov, and Borisenko are returning after 173 days in space where they served as members of the Expedition 49 and 50 crews onboard the International Space Station. Photo Credit: (NASA/Bill Ingalls)

  3. Expedition 50 Soyuz MS-02 Landing

    NASA Image and Video Library

    2017-04-10

    nhq201704100029 (April 10, 2017) --- NASA astronaut Shane Kimbrough rests in a chair outside the Soyuz MS-02 spacecraft just minutes after he, Russian cosmonaut Sergey Ryzhikov of Roscosmos, and Russian cosmonaut Andrey Borisenko of Roscosmos landed in a remote area near the town of Zhezkazgan, Kazakhstan on Monday, April 10, 2017 (Kazakh time). Kimbrough, Ryzhikov, and Borisenko are returning after 173 days in space where they served as members of the Expedition 49 and 50 crews onboard the International Space Station. Photo Credit: (NASA/Bill Ingalls)

  4. Expedition 50 Soyuz MS-02 Landing

    NASA Image and Video Library

    2017-04-10

    nhq201704100028 (April 10, 2017) --- Russian cosmonaut Sergey Ryzhikov of Roscosmos rests in a chair outside the Soyuz MS-02 spacecraft just minutes after he, NASA astronaut Shane Kimbrough, and Russian cosmonaut Andrey Borisenko of Roscosmos landed in a remote area near the town of Zhezkazgan, Kazakhstan on Monday, April 10, 2017 (Kazakh time). Kimbrough, Ryzhikov, and Borisenko are returning after 173 days in space where they served as members of the Expedition 49 and 50 crews onboard the International Space Station. Photo Credit: (NASA/Bill Ingalls)

  5. Expedition 50 Soyuz MS-02 Landing

    NASA Image and Video Library

    2017-04-10

    nhq201704100026 (April 10, 2017) --- NASA astronaut Shane Kimbrough is helped out of the Soyuz MS-02 spacecraft just minutes after he, Russian cosmonaut Sergey Ryzhikov of Roscosmos, and Russian cosmonaut Andrey Borisenko of Roscosmos landed in a remote area near the town of Zhezkazgan, Kazakhstan on Monday, April 10, 2017 (Kazakh time). Kimbrough, Ryzhikov, and Borisenko are returning after 173 days in space where they served as members of the Expedition 49 and 50 crews onboard the International Space Station. Photo Credit: (NASA/Bill Ingalls)

  6. Expedition 50 Soyuz MS-02 Landing

    NASA Image and Video Library

    2017-04-10

    nhq201704100023 (April 10, 2017) --- Russian cosmonaut Sergey Ryzhikov of Roscosmos is helped out of the Soyuz MS-02 spacecraft just minutes after he, NASA astronaut Shane Kimbrough, and Russian cosmonaut Andrey Borisenko of Roscosmos landed in a remote area near the town of Zhezkazgan, Kazakhstan on Monday, April 10, 2017 (Kazakh time). Kimbrough, Ryzhikov, and Borisenko are returning after 173 days in space where they served as members of the Expedition 49 and 50 crews onboard the International Space Station. Photo Credit: (NASA/Bill Ingalls)

  7. Expedition 50 Soyuz MS-02 Landing

    NASA Image and Video Library

    2017-04-10

    nhq201704100030 (April 10, 2017) --- NASA astronaut Shane Kimbrough, left, Russian cosmonaut Sergey Ryzhikov of Roscosmos, center, and Russian cosmonaut Andrey Borisenko of Roscosmos sit in chairs outside the Soyuz MS-02 spacecraft a few moments after they landed in a remote area near the town of Zhezkazgan, Kazakhstan on Monday, April 10, 2017 (Kazakh time). Kimbrough, Ryzhikov, and Borisenko are returning after 173 days in space where they served as members of the Expedition 49 and 50 crews onboard the International Space Station. Photo Credit: (NASA/Bill Ingalls)

  8. Expedition 50 Soyuz MS-02 Landing

    NASA Image and Video Library

    2017-04-10

    nhq201704100034 (April 10, 2017) --- Russian cosmonaut Sergey Ryzhikov of Roscosmos is carried into a medical tent shortly after he, NASA astronaut Shane Kimbrough, and Russian cosmonaut Andrey Borisenko of Roscosmos landed in their Soyuz MS-02 spacecraft in a remote area near the town of Zhezkazgan, Kazakhstan on Monday, April 10, 2017 (Kazakh time). Kimbrough, Ryzhikov, and Borisenko are returning after 173 days in space where they served as members of the Expedition 49 and 50 crews onboard the International Space Station. Photo Credit: (NASA/Bill Ingalls)

  9. Expedition 50 Soyuz MS-02 Landing

    NASA Image and Video Library

    2017-04-10

    nhq201704100040 (April 10, 2017) --- A Russian support helicopter leaves the Soyuz MS-02 landing site shortly after the capsule landed with Expedition 50 Commander Shane Kimbrough of NASA and Flight Engineers Sergey Ryzhikov and Andrey Borisenko of Roscosmos near the town of Zhezkazgan, Kazakhstan on Monday, April 10, 2017 (Kazakh time). Kimbrough, Ryzhikov, and Borisenko are returning after 173 days in space where they served as members of the Expedition 49 and 50 crews onboard the International Space Station. Photo Credit: (NASA/Bill Ingalls)

  10. Expedition 50 Soyuz MS-02 Landing

    NASA Image and Video Library

    2017-04-10

    nhq201704100037 (April 10, 2017) --- Russian support personnel work around the Soyuz MS-02 spacecraft shortly after it landed with Expedition 50 Commander Shane Kimbrough of NASA and Flight Engineers Sergey Ryzhikov and Andrey Borisenko of Roscosmos near the town of Zhezkazgan, Kazakhstan on Monday, April 10, 2017 (Kazakh time). Kimbrough, Ryzhikov, and Borisenko are returning after 173 days in space where they served as members of the Expedition 49 and 50 crews onboard the International Space Station. Photo Credit: (NASA/Bill Ingalls)

  11. Expedition 50 Soyuz MS-02 Landing

    NASA Image and Video Library

    2017-04-11

    nhq201704110055 (April 101, 2017) --- Officials, family, and media gather to welcome home Expedition 50 Flight Engineers Sergey Ryzhikov, foreground, and Andrey Borisenko of Roscosmos at the Chkalovsky Airport in Star City, Russia several hours after they and NASA astronaut Shane Kimbrough landed their Soyuz MS-02 spacecraft in a remote area outside the town of Zhezkazgan, Kazakhstan, on Tuesday, April 11, 2017 (Kazakh time). Kimbrough, Ryzhikov, and Borisenko are returning after 173 days in space where they served as members of the Expedition 49 and 50 crews onboard the International Space Station. Photo Credit: (NASA/Bill Ingalls)

  12. Expedition 50 Soyuz MS-02 Landing

    NASA Image and Video Library

    2017-04-10

    nhq201704100022 (April 10, 2017) --- Russian Search and Rescue teams arrive at the Soyuz MS-02 spacecraft shortly after it landed with Expedition 50 Commander Shane Kimbrough of NASA and Flight Engineers Sergey Ryzhikov and Andrey Borisenko of Roscosmos near the town of Zhezkazgan, Kazakhstan on Monday, April 10, 2017 (Kazakh time). Kimbrough, Ryzhikov, and Borisenko are returning after 173 days in space where they served as members of the Expedition 49 and 50 crews onboard the International Space Station. Photo Credit: (NASA/Bill Ingalls)

  13. Expedition 50 Soyuz MS-02 Landing

    NASA Image and Video Library

    2017-04-10

    nhq201704100039 (April 10, 2017) --- Russian support personnel work around the Soyuz MS-02 spacecraft shortly after it landed with Expedition 50 Commander Shane Kimbrough of NASA and Flight Engineers Sergey Ryzhikov and Andrey Borisenko of Roscosmos near the town of Zhezkazgan, Kazakhstan on Monday, April 10, 2017 (Kazakh time). Kimbrough, Ryzhikov, and Borisenko are returning after 173 days in space where they served as members of the Expedition 49 and 50 crews onboard the International Space Station. Photo Credit: (NASA/Bill Ingalls)

  14. Expedition 50 Soyuz MS-02 Landing

    NASA Image and Video Library

    2017-04-10

    nhq201704100032 (April 10, 2017) --- Russian cosmonaut Andrey Borisenko of Roscosmos rests in a chair outside the Soyuz MS-02 spacecraft just minutes after he, NASA astronaut Shane Kimbrough, and Russian cosmonaut Sergey Ryzhikov of Roscosmos landed in a remote area near the town of Zhezkazgan, Kazakhstan on Monday, April 10, 2017 (Kazakh time). Kimbrough, Ryzhikov, and Borisenko are returning after 173 days in space where they served as members of the Expedition 49 and 50 crews onboard the International Space Station. Photo Credit: (NASA/Bill Ingalls)

  15. Expedition 50 Soyuz MS-02 Landing

    NASA Image and Video Library

    2017-04-11

    nhq201704110056 (April 101, 2017) --- Officials, family, and media gather to welcome home Expedition 50 Flight Engineers Sergey Ryzhikov, foreground, and Andrey Borisenko of Roscosmos at the Chkalovsky Airport in Star City, Russia several hours after they and NASA astronaut Shane Kimbrough landed their Soyuz MS-02 spacecraft in a remote area outside the town of Zhezkazgan, Kazakhstan, on Tuesday, April 11, 2017 (Kazakh time). Kimbrough, Ryzhikov, and Borisenko are returning after 173 days in space where they served as members of the Expedition 49 and 50 crews onboard the International Space Station. Photo Credit: (NASA/Bill Ingalls)

  16. Expedition 50 Soyuz MS-02 Landing

    NASA Image and Video Library

    2017-04-10

    nhq201704100031 (April 10, 2017) --- NASA astronaut Shane Kimbrough rests in a chair outside the Soyuz MS-02 spacecraft just minutes after he, Russian cosmonaut Sergey Ryzhikov of Roscosmos, and Russian cosmonaut Andrey Borisenko of Roscosmos landed in a remote area near the town of Zhezkazgan, Kazakhstan on Monday, April 10, 2017 (Kazakh time). Kimbrough, Ryzhikov, and Borisenko are returning after 173 days in space where they served as members of the Expedition 49 and 50 crews onboard the International Space Station. Photo Credit: (NASA/Bill Ingalls)

  17. Expedition 50 Soyuz MS-02 Landing

    NASA Image and Video Library

    2017-04-10

    nhq201704100024 (April 10, 2017) --- Russian cosmonaut Sergey Ryzhikov of Roscosmos is helped out of the Soyuz MS-02 spacecraft just minutes after he, NASA astronaut Shane Kimbrough, and Russian cosmonaut Andrey Borisenko of Roscosmos landed in a remote area near the town of Zhezkazgan, Kazakhstan on Monday, April 10, 2017 (Kazakh time). Kimbrough, Ryzhikov, and Borisenko are returning after 173 days in space where they served as members of the Expedition 49 and 50 crews onboard the International Space Station. Photo Credit: (NASA/Bill Ingalls)

  18. Expedition 50 Soyuz MS-02 Landing

    NASA Image and Video Library

    2017-04-10

    nhq201704100041 (April 10, 2017) --- Russian helicopter crew members wait in the cockpit of an MI-8 at the Soyuz MS-02 landing site after the spacecraft landed with Expedition 50 Commander Shane Kimbrough of NASA and Flight Engineers Sergey Ryzhikov and Andrey Borisenko of Roscosmos near the town of Zhezkazgan, Kazakhstan on Monday, April 10, 2017 (Kazakh time). Kimbrough, Ryzhikov, and Borisenko are returning after 173 days in space where they served as members of the Expedition 49 and 50 crews onboard the International Space Station. Photo Credit: (NASA/Bill Ingalls)

  19. Expedition 50 Soyuz MS-02 Landing

    NASA Image and Video Library

    2017-04-10

    nhq201704100047 (April 10, 2017) --- NASA astronaut Shane Kimbrough arrives at the Karaganda Airport in Kazakhstan airport after he, Russian cosmonaut Sergey Ryzhikov of Roscosmos and, Russian cosmonaut Andrey Borisenko of Roscosmos landed in their Soyuz MS-02 spacecraft in a remote area near the town of Zhezkazgan, Kazakhstan on Monday, April 10, 2017 (Kazakh time). Kimbrough, Ryzhikov, and Borisenko are returning after 173 days in space where they served as members of the Expedition 49 and 50 crews onboard the International Space Station. Photo Credit: (NASA/Bill Ingalls)

  20. MS-ONLINE Mass Spectral Database

    NASA Astrophysics Data System (ADS)

    Tokizane, Soichi; Nagaoka, Nobuaki

    A mass spectral database, MS-ONLINE, is described which is produced by FIZ Chemie, in Federal Republic of Germany and offered online through the INKADATA system. The data source of this database is WILEY/NBS MASS SPECTRAL DATA BASE and it includes 80,680 spectra. Spectral data can be retrieved from a substance search (by assigning molecular weight, molecular formula or name), a specific peak search, or a similarity search of peak patterns called SISCOM search. Further more, the system has functions supporting the component identification of mixtures and the identification from an isotopic abundance. The algorism of the SISCOM search is explained in detail.

  1. Simultaneous quantification of the organophosphorus pesticides dimethoate and omethoate in porcine plasma and urine by LC-ESI-MS/MS and flow-injection-ESI-MS/MS.

    PubMed

    John, Harald; Eddleston, Michael; Clutton, R Eddie; Worek, Franz; Thiermann, Horst

    2010-05-15

    Dimethoate is an organophosphorus toxicant used in agri- and horticulture as a systemic broad-spectrum insecticide. It also exhibits toxic activity towards mammalian organism provoked by catalytic desulfuration in the liver producing its oxon-derivative omethoate thus inhibiting acetylcholinesterase, initiating cholinergic crisis and ultimately leading to death by respiratory paralysis and cardiovascular collapse. Pharmaco- and toxicokinetic studies in animal models help to broaden basic understanding of medical intervention by antidotes and supportive care. Therefore, we developed and validated a LC-ESI-MS/MS method suitable for the simultaneous, selective, precise (RSD(intra-day) 1-8%; RSD(inter-day) 5-14%), accurate (intra-day: 95-107%; inter-day: 90-115%), and robust quantification of both pesticides from porcine urine and plasma after deproteinization by precipitation and extensive dilution (1:11,250 for plasma and 1:40,000 for urine). Accordingly, lower limits of quantification (0.24-0.49 microg/ml plasma and 0.78-1.56 microg/ml urine) and lower limits of detection (0.12-0.24 microg/ml plasma and 0.39-0.78 microg/ml urine) were equivalent to quite low absolute on-column amounts (1.1-2.1 pg for plasma and 2.0-3.9 pg for urine). The calibration range (0.24-250 microg/ml plasma and 0.78-200 microg/ml urine) was subdivided into two linear ranges (r(2)>or=0.998) each covering nearly two orders of magnitude. The lack of any interfering peak in 6 individual blank specimens from plasma and urine demonstrated the high selectivity of the method. Furthermore, extensive sample dilution causing lowest concentration of potentially interfering matrix ingredients prompted us to develop and validate an additional flow-injection method (FI-ESI-MS/MS). Validation characteristics were as good as for the chromatographic method but sample throughput was enhanced by a factor of 6. Effects on ionization provoked by plasma and urine matrix from 6 individuals as well as in the

  2. Determination of Plutonium Isotope Ratios at Very Low Levels by ICP-MS using On-Line Electrochemically Modulated Separations

    SciTech Connect

    Liezers, Martin; Lehn, Scott A; Olsen, Khris B; Farmer, Orville T; Duckworth, Douglas C

    2009-10-01

    Electrochemically modulated separations (EMS) are shown to be a rapid and selective means of extracting and concentrating Pu from complex solutions prior to isotopic analysis by inductively coupled plasma mass spectrometry (ICP-MS). This separation is performed in a flow injection mode, on-line with the ICP-MS. A three-electrode, flow-by electrochemical cell is used to accumulate Pu at an anodized glassy carbon electrode by redox conversion of Pu(III) to Pu (IV&VI). The entire process takes place in 2% v/v (0.46M) HNO3. No redox chemicals or acid concentration changes are required. Plutonium accumulation and release is redox dependent and controlled by the applied cell potential. Thus large transient volumetric concentration enhancements can be achieved. Based on more negative U(IV) potentials relative to Pu(IV), separation of Pu from uranium is efficient, thereby eliminating uranium hydride interferences. EMS-ICP-MS isotope ratio measurement performance will be presented for femtogram to attogram level plutonium concentrations.

  3. Validation of Electrochemically Modulated Separations Performed On-Line with MC-ICP-MS for Uranium and Plutonium Isotopic Analyses

    SciTech Connect

    Liezers, Martin; Olsen, Khris B.; Mitroshkov, Alexandre V.; Duckworth, Douglas C.

    2010-08-11

    The most time consuming process in uranium or plutonium isotopic analyses is performing the requisite chromatographic separation of the actinides. Filament preparation for thermal ionization (TIMS) adds further delays, but is generally accepted due to the unmatched performance in trace isotopic analyses. Advances in Multi-Collector Inductively Coupled Plasma Mass Spectrometry (MC-ICP-MS) are beginning to rival the performance of TIMS. Methods, such as Electrochemically Modulated Separations (EMS) can efficiently pre-concentrate U or Pu quite selectively from small solution volumes in a matrix of 0.5 M nitric acid. When performed in-line with ICP-MS, the rapid analyte release from the electrode is fast, and large transient analyte signal enhancements of >100 fold can be achieved as compared to more conventional continuous nebulization of the original starting solution. This makes the approach ideal for very low level isotope ratio measurements. In this paper, some aspects of EMS performance are described. These include low level Pu isotope ratio behavior versus concentration by MC-ICP-MS and uranium rejection characteristics that are also important for reliable low level Pu isotope ratio determinations.

  4. Simultaneous quantitative analysis of nine vitamin D compounds in human blood using LC-MS/MS.

    PubMed

    Abu Kassim, Nur Sofiah; Gomes, Fabio P; Shaw, Paul Nicholas; Hewavitharana, Amitha K

    2016-01-01

    It has been suggested that each member of the family of vitamin D compounds may have different function(s). Therefore, selective quantification of each compound is important in clinical research. Development and validation attempts of a simultaneous determination method of 12 vitamin D compounds in human blood using precolumn derivatization followed by LC-MS/MS is described. Internal standard calibration with 12 stable isotope labeled analogs was used to correct for matrix effects in MS detector. Nine vitamin D compounds were quantifiable in blood samples with detection limits within femtomole levels. Serum (compared with plasma) was found to be a more suitable sample type, and protein precipitation (compared with saponification) a more effective extraction method for vitamin D assay.

  5. Analysis of peptides using an integrated microchip HPLC-MS/MS system.

    SciTech Connect

    Kirby, Brian J.; Chirica, Gabriela S.; Reichmuth, David S.

    2004-06-01

    Hyphendated LC-MS techniques are quickly becoming the standard tool for protemic analyses. For large homogeneous samples, bulk processing methods and capillary injection and separation techniques are suitable. However, for analysis of small or heterogeneous samples, techniques that can manipulate picoliter samples without dilution are required or samples will be lost or corrupted; further, static nanospray-type flowrates are required to maximize SNR. Microchip-level integration of sample injection with separation and mass spectrometry allow small-volume analytes to be processed on chip and immediately injected without dilution for analysis. An on-chip HPLC was fabricated using in situ polymerization of both fixed and mobile polymer monoliths. Integration of the chip with a nanospray MS emitter enables identification of peptides by the use of tandem MS. The chip is capable of analyzing of very small sample volumes (< 200 pl) in short times (< 3 min).

  6. Sensitive glucagon quantification by immunochemical and LC-MS/MS methods.

    PubMed

    Lapko, Veniamin N; Miller, Patrick S; Brown, G Paul; Islam, Rafiqul; Peters, Sarah K; Sukovaty, Richard L; Ruhn, Peggy F; Kafonek, Chris J

    2013-12-01

    The peptide hormone glucagon plays an important role in homeostasis of glucose concentrations in the blood. Its biological importance is evidenced through the conservation of its peptide sequence between species. Reliable assays for glucagon in biological samples are important for gaining a better understanding of the pathology and treatment of diabetes. Numerous assays are available for the analysis of glucagon in biological samples, the majority of which employ an immunochemical approach and have been available for many years. However, recent advances in MS instrumentation and the amenability of glucagon for analysis by LC-MS/MS has brought these new methods to the forefront. Concentrations of glucagon determined from different methods are not always consistent and this review provides suggestions of how to improve the reliability of methods for glucagon analysis.

  7. Identification and quantification of carotenoids, by HPLC-PDA-MS/MS, from Amazonian fruits.

    PubMed

    de Rosso, Veridiana V; Mercadante, Adriana Z

    2007-06-27

    The major and minor carotenoids from six fruits, buriti (Mauritia vinifera), mamey (Mammea americana), marimari (Geoffrola striata), peach palm (Bactrys gasipaes), physalis (Physalis angulata), and tucuma (Astrocaryum aculeatum), all native to the Amazonia region, were determined by high-performance liquid chromatography-photodiode array detector-mass spectrometry detector (HPLC-PDA-MS/MS), fulfilling the recommended criteria for identification. A total of 60 different carotenoids were separated on a C30 column, all-trans-beta-carotene being the major carotenoid found in all fruits. The presence of apo-10'-beta-carotenol, found in mamey, was not previously reported in foods. In addition, this is the first time that the identification of beta-zeacarotene in natural sources is supported by MS data. The total carotenoid content ranged from 38 microg/g in marimari to 514 microg/g in buriti. All fruits analyzed can be considered good sources of provitamin A, especially buriti, with 7280 RE/100 g.

  8. 61. MISSISSIPPI, NOXUBEE CO. MACON MAHORNER'S BRIDGE Ms. 14, 6 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    61. MISSISSIPPI, NOXUBEE CO. MACON MAHORNER'S BRIDGE Ms. 14, 6 miles E to McLeod, 4.5 miles S on McLeod-Shuqualak road. Overall view of bridge, looking E along N side, from below deck level. Sarcone Photography, Columbus, Ms. Sep 1978. - Bridges of the Upper Tombigbee River Valley, Columbus, Lowndes County, MS

  9. Determination of Meropenem in Bacterial Media by LC-MS/MS

    PubMed Central

    Huang, Liusheng; Haagensen, Janus; Verotta, Davide; Lizak, Patricia; Aweeka, Francesca; Yang, Katherine

    2014-01-01

    To support the development of a dynamic in vitro human Pharmacokinetic/Pharmacodynamic simulation model for biofilm-mediated infections and study stability of meropenem, an LC-MS/MS method for the determination of meropenem in Luria Bertani (LB) media was developed and validated in an API2000 LC-MS/MS system. A partial validation was also performed in M9 media. Sample aliquots of 100 μL (or 25 μL for M9 media) were mixed with the internal standard (IS) ceftazidime and filtered. The filtrate was directly injected onto a C8 column eluted with ammonium formate (10mM, pH4) and acetonitrile (0.1% formic acid) in a gradient mode. ESI+ and MRM with ion pair m/z 384 → 68 for meropenem and m/z 547 → 468 for the IS were used for quantification. The calibration curve concentration range was 50 to 25,000 ng/mL. The recovery was over 98%. In LB media, significant signal suppression was observed throughout the time period of detection when compared with mobile phase solvents, but the matrix effect was compensated well with the IS. In M9 media, much less signal suppression was observed. The method is simple, fast, and reliable. Using the method, stability of meropenem in LB and M9 media were tested. No significant degradation was observed for at least 8 hours in both LB media (37 °C) and M9 media (30 °C), but more than 15% degradation was observed overnight (∼20hr). The method was transferred to an API5000 LC-MS/MS system using meropenem-d6 as the IS. PMID:24861874

  10. Determination of meropenem in bacterial media by LC-MS/MS.

    PubMed

    Huang, Liusheng; Haagensen, Janus; Verotta, Davide; Lizak, Patricia; Aweeka, Francesca; Yang, Katherine

    2014-06-15

    To support the development of a dynamic in vitro human pharmacokinetic/pharmacodynamic simulation model for biofilm-mediated infections and study stability of meropenem, an LC-MS/MS method for the determination of meropenem in Luria Bertani (LB) media was developed and validated in an API2000 LC-MS/MS system. A partial validation was also performed in M9 media. Sample aliquots of 100μL (or 25μL for M9 media) were mixed with the internal standard (IS) ceftazidime and filtered. The filtrate was directly injected onto a C8 column eluted with ammonium formate (10mM, pH 4) and acetonitrile (0.1% formic acid) in a gradient mode. ESI(+) and MRM with ion pair m/z 384→68 for meropenem and m/z 547→468 for the IS were used for quantification. The calibration curve concentration range was 50 to 25,000ng/mL. The recovery was over 98%. In LB media, significant signal suppression was observed throughout the time period of detection when compared with mobile phase solvents, but the matrix effect was compensated well with the IS. In M9 media, much less signal suppression was observed. The method is simple, fast, and reliable. Using the method, stability of meropenem in LB and M9 media were tested. No significant degradation was observed for at least 8h in both LB media (37°C) and M9 media (30°C), but more than 15% degradation was observed overnight (∼20h). The method was transferred to an API5000 LC-MS/MS system using meropenem-d6 as the IS. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Determination of Aflatoxin B1 in Smokeless Tobacco Products by Use of UHPLC-MS/MS.

    PubMed

    Zitomer, Nicholas; Rybak, Michael E; Li, Zhong; Walters, Matthew J; Holman, Matthew R

    2015-10-21

    This work developed a UHPLC-MS/MS method for the detection and quantitation of aflatoxins in smokeless tobacco products, which was then used to determine aflatoxin B1 concentrations in 32 smokeless tobacco products commercially available in the United States. Smokeless tobacco products were dried, milled, and amended with (13)C17-labeled internal standards, extracted in water/methanol solution in the presence of a surfactant, isolated through use of immunoaffinity column chromatography, and reconstituted in mobile phase prior to UHPLC-MS/MS analysis. The method was capable of baseline separation of aflatoxins B1, B2, G1, and G2 in a 2.5 min run by use of a fused core C18 column and a water/methanol gradient. MS/MS transition (m/z) 313.3 → 241.2 was used for aflatoxin B1 quantitation, with 313.3 → 285.1 used for confirmation. The limit of detection (LOD) for aflatoxin B1 was 0.007 parts per billion (ppb). Method imprecision for aflatoxin B1 (expressed as coefficient of variation) ranged from 5.5 to 9.4%. Spike recoveries were 105-111%. Aflatoxin B1 concentrations in the smokeless tobacco products analyzed ranged from

  12. Analysis of benzodiazepines and their metabolites using DBS cards and LC-MS/MS.

    PubMed

    Lee, Heesang; Park, Yujin; Jo, Jiyeong; In, Sangwhan; Park, Yonghoon; Kim, Eunmi; Pyo, Jaesung; Choe, Sanggil

    2015-10-01

    Dried Blood Spot (DBS) has been used a blood extraction method for inherited metabolic disorder screening since 1960s. With introduction of LC-MS/MS, not only DBS could be used to analysis drugs in small blood volume, but in various fields, such as toxicology, drug therapeutic monitoring, drug diagnostic screening, and illicit drugs. In toxicology field, many drugs (e.g. benzodiazepines, acetaminophen, small molecule drugs) have been tested with DBS. Compared with earlier blood extraction methods (SPE and LLE), DBS has lots of advantages; lower blood volume (less than 50μL), shorter analysis time caused by a more concise analysis procedure and lower cost. We optimized the DBS procedure and LC-MS/MS conditions for 18 benzodiazepines, seven benzodiazepine metabolites, and one z-drug (zolpidem) analysis in blood. 30μL of whole blood was spotted on FTA DMPK card C and dried for 2h in a desiccator. A 6-mm disk was punched and vortexed for 1min in a centrifuge tube with 300μL methanol/acetonitrile mixture (1:1, v/v). After evaporation, redissolved in 100μL mobile phase of LC-MS/MS and 5μL was injected. In the analysis for 26 target compounds in blood, all of the method validation parameters - LLOD, LLOQ, accuracy (intra- and inter-assay), and precision (intra- and inter-assay) - were satisfied with method validation criteria, within 15%. The results of matrix effect, recovery, and process efficiency were good. We developed a fast and reliable sample preparation method using DBS for 26 benzodiazepines, benzodiazepine metabolites, and z-drug (zolpidem).

  13. Measures of visual pathway structure and function in MS: Clinical usefulness and role for MS trials.

    PubMed

    Galetta, Kristin M; Balcer, Laura J

    2013-07-01

    Over the past decade, the visual pathway in multiple sclerosis (MS) has become an important system for assessing both patient function and disease burden. Abnormalities of low-contrast acuity, long recognized as important correlates of driving, facial recognition, and other activities of daily living, are now noted to be common among patients with MS, even among those with no history of acute optic neuritis (ON). Low-contrast letter acuity scores correlate well with brain MRI lesion burden, visual-evoked potential (VEP) amplitudes, health-related quality of life (QOL), and retinal nerve fiber layer (RNFL) axonal and neuronal loss as measured by optical coherence tomography (OCT). Axonal and neuronal degeneration in MS is likely to be an important cause of visual impairment and disability, particularly among patients with progressive MS subtypes. With the advent of OCT and the use of low-contrast letter acuity charts in MS research and clinical trials, the structure-function correlations afforded by the anterior visual pathway can be assessed and potentially harnessed as a model for testing new therapies. Recent advances in OCT, such as high resolution spectral-domain techniques and computerized algorithms for image analysis, have allowed for measurement of specific retinal layers, including the ganglion cell (GCL) neuronal layer and its intimately associated, thin layer of interneurons, the inner plexiform layer (IPL). Longitudinal collaborative studies of GCL+IPL thinning and RNFL axonal loss are providing an in vivo view into neuroretinal pathology, and are providing new insights into how the visual pathway may reflect overall mechanisms of disease in MS. Copyright © 2012 Elsevier B.V. All rights reserved.

  14. Adhesive blood microsampling systems for steroid measurement via LC-MS/MS in the rat.

    PubMed

    Heussner, Kirsten; Rauh, Manfred; Cordasic, Nada; Menendez-Castro, Carlos; Huebner, Hanna; Ruebner, Matthias; Schmidt, Marius; Hartner, Andrea; Rascher, Wolfgang; Fahlbusch, Fabian B

    2017-04-01

    Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS) allows for the direct analysis of multiple hormones in a single probe with minimal sample volume. Rodent-based animal studies strongly rely on microsampling, such as the dry blood spot (DBS) method. However, DBS suffers the drawback of hematocrit-dependence (non-volumetric). Hence, novel volumetric microsampling techniques were introduced recently, allowing sampling of fixed accurate volumes. We compared these methods for steroid analysis in the rat to improve inter-system comparability. We analyzed steroid levels in blood using the absorptive microsampling devices Whatman® 903 Protein Saver Cards, Noviplex™ Plasma Prep Cards and the Mitra™ Microsampling device and compared the obtained results to the respective EDTA plasma levels. Quantitative steroid analysis was performed via LC-MS/MS. For the determination of the plasma volume factor for each steroid, their levels in pooled blood samples from each human adults and rats (18weeks) were compared and the transferability of these factors was evaluated in a new set of juvenile (21days) and adult (18weeks) rats. Hematocrit was determined concomitantly. Using these approaches, we were unable to apply one single volume factor for each steroid. Instead, plasma volume factors had to be adjusted for the recovery rate of each steroid and device individually. The tested microsampling systems did not allow the use of one single volume factor for adult and juvenile rats based on an unexpectedly strong hematocrit-dependency and other steroid specific (pre-analytic) factors. Our study provides correction factors for LC-MS/MS steroid analysis of volumetric and non-volumetric microsampling systems in comparison to plasma. It argues for thorough analysis of chromatographic effects before the use of novel volumetric systems for steroid analysis. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. [Simultaneous determination of 11 mycotoxins in malt by isotope internal standard-UPLC-MS/MS].

    PubMed

    Wang, Sha; Kong, Wei-jun; Yang, Mei-hua

    2016-01-01

    A suitable ultra-high performance liquid chromatography coupled with tandem mass spectrometry (UPLC-MS/MS) method was developed for the determination of 11 mycotoxins with isotope internal standard in malt. The mycotoxins in malt were extracted and purified by one-step ultrasonic extraction procedure using acetonitrile/water/acetic acid (80 : 19 : 1), and then detected and confirmed by UPLC-MS/MS, and quantified by isotope labeled AFB1 ([13C17]-AFB1) and ZEN ([13C18]-ZEN) internal standards. Rapid separation of the 11 mycotoxins was successfully achieved on a Phenomenex Kinetex C18 column (100 mm x 2.1 mm, 2.6 μm) with gradient elution using the mobile phase of methanol containing 0.1% formic acid and 2 mmol x L(-1) ammonium acetate in water. Simultaneous acquisition was performed in multiple reaction monitoring (MRM) mode with electrospray ionization (ESI) source operated in both positive and negative ionization modes. The established method provided a good linearity for the 11 mycotoxins within their respective linear ranges with correlation coefficients all higher than 0.999 1. The average recoveries ranged from 75.0% to 117.0% with relative standard deviations (RSDs) below 5.1%. The limits of detection (LODs) and quantitation (LOQs) ranged from 0.05 to 30 μg x kg(-1) and 0.15 to 87.5 μg x kg(-1), respectively, which were below the maximum residue levels (MRLs) set by the European Union. Twenty malt samples were analyzed and nine samples were detected with mycotoxins, which were confirmed according to the same fragment ions found in positive samples and the standards at the same retention time. This study has demonstrated that the one-step extraction procedure of mycotoxins from complex matrices coupled to UPLC-MS/MS method is simple, quick, accurate and sensitive for quantitative and qualitative analysis of multiple mycotoxins in malt.

  16. UFLC-ESI-MS/MS analysis of multiple mycotoxins in medicinal and edible Areca catechu.

    PubMed

    Liu, Hongmei; Luo, Jiaoyang; Kong, Weijun; Liu, Qiutao; Hu, Yichen; Yang, Meihua

    2016-05-01

    A robust, sensitive and reliable ultra fast liquid chromatography combined with electrospray ionization tandem mass spectrometry (UFLC-ESI-MS/MS) was optimized and validated for simultaneous identification and quantification of eleven mycotoxins in medicinal and edible Areca catechu, based on one-step extraction without any further clean-up. Separation and quantification were performed in both positive and negative modes under multiple reaction monitoring (MRM) in a single run with zearalanone (ZAN) as internal standard. The chromatographic conditions and MS/MS parameters were carefully optimized. Matrix-matched calibration was recommended to reduce matrix effects and improve accuracy, showing good linearity within wide concentration ranges. Limits of quantification (LOQ) were lower than 50 μg kg(-1), while limits of detection (LOD) were in the range of 0.1-20 μg kg(-1). The accuracy of the developed method was validated for recoveries, ranging from 85% to 115% with relative standard deviation (RSD) ≤14.87% at low level, from 75% to 119% with RSD ≤ 14.43% at medium level and from 61% to 120% with RSD ≤ 13.18% at high level, respectively. Finally, the developed multi-mycotoxin method was applied for screening of these mycotoxins in 24 commercial samples. Only aflatoxin B2 and zearalenone were found in 2 samples. This is the first report on the application of UFLC-ESI(+/-)-MS/MS for multi-class mycotoxins in A. catechu. The developed method with many advantages of simple pretreatment, rapid determination and high sensitivity is a proposed candidate for large-scale detection and quantification of multiple mycotoxins in other complex matrixes.

  17. Identification of chemical markers in Cordyceps sinensis by HPLC-MS/MS.

    PubMed

    Hu, Hankun; Xiao, Ling; Zheng, Baogen; Wei, Xin; Ellis, Alexis; Liu, Yi-Ming

    2015-10-01

    Authentication and quality assessment of Cordyceps sinensis, a precious and pricey natural product that offers a variety of health benefits, is highly significant. To identify effective chemical markers, authentic C. sinensis was thoroughly screened by using HPLC-MS/MS. In addition to many previously reported ingredients, two glycosides, i.e., cyclo-Ala-Leu-rhamnose and Phe-o-glucose, were detected for the first time in this material. Six ingredients detected, including cordycepin, D-mannitol, Phe, Phe-o-glucose, cyclo-Gly-Pro, and cyclo-Ala-Leu-rhamnose, were selected as a collection of chemical markers. An HPLC-MS/MS method was developed to simultaneously quantify them with sensitivity and specificity. The method had limits of detection ranging from 0.008 μg mL(-1) for cordycepin to 0.75 μg mL(-1) for cyclo-Gly-Pro. Recovery was found between 96 and 103 % in all tests. To evaluate the effectiveness of the marker collection proposed, five authentic C. sinensis samples and five samples of its substitutes were analyzed. Cordycepin, D-mannitol, and Phe were found present in all samples. The contents ranged from 0.0076 to 0.029 % (w/w) for cordycepin, 0.33 to 18.9 % for mannitol, and 0.0013 to 0.642 % for Phe. Interestingly, the two glycosides, Phe-o-glucose and cyclo-Ala-Leu-rhamnose, were detected only in authentic C. sinensis samples. These results indicated that the proposed protocol based on HPLC-MS/MS quantification of the markers might have a great potential in authentication and quality assessment of C. sinensis. Graphical abstract Chemical markers of C. sinensis identified in this work.

  18. PGCA: An algorithm to link protein groups created from MS/MS data

    PubMed Central

    Sasaki, Mayu; Hollander, Zsuzsanna; Smith, Derek; McManus, Bruce; McMaster, W. Robert; Ng, Raymond T.; Cohen Freue, Gabriela V.

    2017-01-01

    The quantitation of proteins using shotgun proteomics has gained popularity in the last decades, simplifying sample handling procedures, removing extensive protein separation steps and achieving a relatively high throughput readout. The process starts with the digestion of the protein mixture into peptides, which are then separated by liquid chromatography and sequenced by tandem mass spectrometry (MS/MS). At the end of the workflow, recovering the identity of the proteins originally present in the sample is often a difficult and ambiguous process, because more than one protein identifier may match a set of peptides identified from the MS/MS spectra. To address this identification problem, many MS/MS data processing software tools combine all plausible protein identifiers matching a common set of peptides into a protein group. However, this solution introduces new challenges in studies with multiple experimental runs, which can be characterized by three main factors: i) protein groups’ identifiers are local, i.e., they vary run to run, ii) the composition of each group may change across runs, and iii) the supporting evidence of proteins within each group may also change across runs. Since in general there is no conclusive evidence about the absence of proteins in the groups, protein groups need to be linked across different runs in subsequent statistical analyses. We propose an algorithm, called Protein Group Code Algorithm (PGCA), to link groups from multiple experimental runs by forming global protein groups from connected local groups. The algorithm is computationally inexpensive and enables the connection and analysis of lists of protein groups across runs needed in biomarkers studies. We illustrate the identification problem and the stability of the PGCA mapping using 65 iTRAQ experimental runs. Further, we use two biomarker studies to show how PGCA enables the discovery of relevant candidate protein group markers with similar but non-identical compositions

  19. A method for quantification of serum tenascin-X by nano-LC/MS/MS.

    PubMed

    Yamada, Kazuo; Watanabe, Atsushi; Takeshita, Haruo; Matsumoto, Ken-Ichi

    2016-08-01

    Complete deficiency of an extracellular matrix tenascin-X (TNX) leads to a classical type of Ehlers-Danlos syndrome (EDS). TNX haploinsufficiency is a cause of hypermobility type of EDS. Human TNX is also present in a serum form (sTNX) with a molecular size of 140kDa. In this study, we established a method for quantification of sTNX using nano-liquid chromatography tandem mass spectrometry (LC/MS/MS) with selected/multiple reaction monitoring. Twelve abundant protein-depleted sera were reduced, alkylated, and digested with Lys-C and trypsin. Subsequently, the digests were fractionated by strong cation exchange chromatography. Optimal and validated transitions of precursor and product ions of the peptides from sTNX were developed on a triple quadrupole mass spectrometer. Serum concentrations of sTNX of healthy individuals were quantified as an average of 144ng/ml. However, sTNX was not detected by this method in serum from a patient with a classical type of EDS in whom sTNX was not found by Western blot analysis. The limit of quantification (LOQ) of sTNX by nano-LC/MS/MS method was 2.8pg whereas the detection sensitivity of sTNX by Western blot analysis was 19pg. The nano-LC/MS/MS method is more sensitive than Western blot analysis. The quantification method will be useful for diagnosis and risk stratification of EDS caused by TNX deficiency and haploinsufficiency. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Development of multi-residue sulfonamide analysis using LC-MS/MS for detection in wastewater and river samples

    USDA-ARS?s Scientific Manuscript database

    A qTOF-LC-MS/MS method was developed for multi-residue analysis of sulfonamides, including sulfathiazole, sulfadiazine, sulfapyridine, sulfamerazine, sulfamethizole, sulfamethazine, sulfachloropydirine, sulfamethoxazole (SMX), sulfadimethoxine, sulfabenzamide, sulfaquinoxaline, and sulfasalazine. Tw...

  1. [Determination method of ultra-high-intensity sweetener, advantame, in processed foods by HPLC and LC-MS/MS].

    PubMed

    Kobayashi, Miki; Terada, Hisaya; Nakajima, Masahiro

    2015-01-01

    A simple method using HPLC and LC-MS/MS was developed for the determination of ultra-high-intensity sweetener, advantame, in processed foods. Advantame was extracted by dialysis, and cleaned up on a Sep-Pak Plus C18 cartridge, then determined by HPLC and LC-MS/MS. The recoveries from 5 kinds of processed foods fortified at the levels of 0.001 g/kg and 0.01 g/kg were 64.1-89.9% (RSD 0.9-6.9%) by HPLC and 68.8-99.9% (RSD 0.8-4.9%) by LC-MS/MS. The quantitation limit was 0.0004 g/kg by HPLC and 0.00004 g/kg by LC-MS/MS.

  2. Techniques for quantitative LC-MS/MS analysis of protein therapeutics: advances in enzyme digestion and immunocapture.

    PubMed

    Fung, Eliza N; Bryan, Peter; Kozhich, Alexander

    2016-04-01

    LC-MS/MS has been investigated to quantify protein therapeutics in biological matrices. The protein therapeutics is digested by an enzyme to generate surrogate peptide(s) before LC-MS/MS analysis. One challenge is isolating protein therapeutics in the presence of large number of endogenous proteins in biological matrices. Immunocapture, in which a capture agent is used to preferentially bind the protein therapeutics over other proteins, is gaining traction. The protein therapeutics is eluted for digestion and LC-MS/MS analysis. One area of tremendous potential for immunocapture-LC-MS/MS is to obtain quantitative data where ligand-binding assay alone is not sufficient, for example, quantitation of antidrug antibody complexes. Herein, we present an overview of recent advance in enzyme digestion and immunocapture applicable to protein quantitation.

  3. Why do Emergency Medical Services (EMS) Professionals Leave EMS?

    PubMed

    Blau, Gary; Chapman, Susan A

    2016-12-01

    The objective was to determine why Emergency Medical Technician (EMT)-Basics and Paramedics leave the Emergency Medical Services (EMS) workforce. Data were collected through annual surveys of nationally registered EMT-Basics and Paramedics from 1999 to 2008. Survey items dealing with satisfaction with the EMS profession, likelihood of leaving the profession, and likelihood of leaving their EMS job were assessed for both EMT-Basics and Paramedics, along with reasons for leaving the profession. Individuals whose responses indicated that they were not working in EMS were mailed a special exit survey to determine the reasons for leaving EMS. The likelihood of leaving the profession in the next year was low for both EMT-Basics and Paramedics. Although overall satisfaction levels with the profession were high, EMT-Basics were significantly more satisfied than Paramedics. The most important reasons for leaving the profession were choosing to pursue further education and moving to a new location. A desire for better pay and benefits was a significantly more important reason for EMT-Paramedics' exit decisions than for EMT-Basics. Given the anticipated increased demand for EMS professionals in the next decade, continued study of issues associated with retention is strongly recommended. Some specific recommendations and suggestions for promoting retention are provided. Blau G , Chapman SA . Why do Emergency Medical Services (EMS) professionals leave EMS? Prehosp Disaster Med. 2016;31(Suppl. 1):s105-s111.

  4. Statistical Assessment of QC Metrics on Raw LC-MS/MS Data.

    PubMed

    Wang, Xia

    2017-01-01

    Data quality assessment is important for reproducibility of proteomics experiments and reusability of proteomics data. We describe a set of statistical tools to routinely visualize and examine the quality control (QC) metrics obtained for raw LC-MS/MS data on different instrument types and mass spectrometers. The QC metrics used here are the identification free QuaMeter metrics. Statistical assessments introduced include (a) principal component analysis, (b) dissimilarity measures, (c) T (2)-chart for quality control, and (d) change point analysis. We demonstrate the workflow by a step-by-step assessment of a subset of Study 5 for the Clinical Proteomics Technology Assessment for Cancer (CPTAC) using our R functions.

  5. Characterization of clinafloxacin photodegradation products by LC-MS/MS and NMR.

    PubMed

    Lovdahl, M J; Priebe, S R

    2000-08-15

    Exposure of clinafloxacin to light results in photochemical degradation. The polar and nonpolar photodegradation products were profiled by HPLC using two sets of conditions. Clinafloxacin was subjected to severe light exposure conditions to obtain elevated levels of the photodegradation products for characterization. The structures of eight new degradation products were elucidated based on information from LC-MS/MS fragmentation and NMR spectra following isolation by preparative HPLC. Two photodegradation routes were identified: (1) dechlorination, followed by further reactions involving the quinolone ring, to yield polar photodegradation products; and (2) degradation of the pyrrolidine side-chain, yielding the nonpolar photodegradation products.

  6. Targeted pesticide residue analysis using triple Quad LC-MS/MS.

    PubMed

    Alder, Lutz

    2011-01-01

    The determination of pesticide residues by HPLC-MS/MS requires decisions on a multitude of analytical parameters. This includes the selection of eluents, columns and ion sources, but also the optimization of the tandem mass spectrometer for the selected target analytes. Another aspect is the use of the restricted acquisition time between two chromatographic data points. An appropriate selection of all these parameters as well as the measures to avoid interference by cross talks and wrong quantitative results by matrix effects is discussed in this chapter.

  7. STS-54 MS2 Harbaugh and MS3 Helms during training in JSC's ETA / airlock

    NASA Technical Reports Server (NTRS)

    1992-01-01

    STS-54 Endeavour, Orbiter Vehicle (OV) 105, Mission Specialist (MS2) Gregory J. Harbaugh, wearing an extravehicular mobility unit (EMU) and communications carrier assembly (CCA), is assisted by MS3 Susan J. Helms during Environmental Test Article (ETA) / Airlock training (STB-SS-956) in JSC's Crew Systems Laboratory Bldg 7. Helms readies the EMU glove as Harbaugh looks on. Though not assigned to the scheduled STS-54 extravehicular activity (EVA), Helms will assist Harbaugh in EVA preparations as she does here and will serve as a backup EVA crewmember. Two crewmembers will perform a four-hour-plus spacewalk during STS-54.

  8. HPLC-ESI-MS/MS determination of zuclopenthixol in a fatal intoxication during psychiatric therapy.

    PubMed

    Kollroser, M; Henning, G; Gatternig, R; Schober, C

    2001-12-01

    The first non-suicidal fatality due to intramuscular administration of Cisordinol (zuclopenthixol, ZPT) is described. A new, rapid, and sensitive method for the determination of ZPT in postmortem specimens has been developed. High performance liquid chromatography electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS) was employed for drug confirmation and quantitation. Sample clean up was performed using a simple liquid-liquid extraction procedure. The postmortem concentration of ZPT in heart blood was 0.68 microg/ml. Furthermore, zotepine, carbamazepine, and chlorprotixene were detected in body fluids. The proposed method enables the unambiguous identification and quantitation of ZPT and other neuroleptic drugs in clinical and forensic specimens.

  9. STS-31 MS Sullivan, MS McCandless, DSO 462 medical device on OV-103 middeck

    NASA Technical Reports Server (NTRS)

    1990-01-01

    STS-31 Mission Specialist (MS) Kathryn D. Sullivan applies a gel to a transducer while MS Bruce McCandless II uses a central venous pressure mouthpiece on the middeck of Discovery, Orbiter Vehicle (OV) 103. The crewmembers are conducting Detailed Supplementary Objective (DSO) 462, Non-Invasive Estimation of Central Venous Pressure. After preparing the transducer, Sullivan will apply it to McCandless' juggler. DSO 462 will measure the physiological adaptation to the headward shift that occurs in microgravity. This non-invasive technique of determining central venous pressure uses the mouthpiece with varying resistance and a probe that utilizes Doppler flowmetry.

  10. STS-54 MS2 Harbaugh and MS3 Helms during slidewire egress training at KSC

    NASA Technical Reports Server (NTRS)

    1993-01-01

    STS-54 Endeavour, Orbiter Vehicle (OV) 105, Mission Specialist (MS2) Gregory J. Harbaugh (left) and MS3 Susan J. Helms, wearing launch and entry suits (LESs) and launch and entry helmets (LEHs), listen to instructions during emergency egress system (slidewire) training at a Kennedy Space Center (KSC) Launch Complex (LC) tower. The two crewmembers, positioned in a slidewire litter (basket), watch as Lockheed (Houston) technician Max Kandler, wearing stocking hat, performs final checks before sending them down the slidewire. The emergency egress training was part of the preflight terminal countdown demonstration tests (TCDTs).

  11. Determination of macrocyclic trichothecenes in mouldy indoor materials by LC-MS/MS.

    PubMed

    Gottschalk, C; Bauer, J; Meyer, K

    2006-09-01

    Stachybotrys occurring in mouldy indoor environments is associated with the so called "sick building syndrome" in humans or cases of idiopathic pulmonary hemorrhages. Samples of mouldy materials from indoor environments (n=15) were analysed for the occurrence of this fungus and its secondary metabolites by a sensitive LC-MS/MS method. In four samples,Stachybotrys and macrocyclic trichothecenes have been detected. Maximum values for Satratoxin G and H in wallpaper were determined with 9.7 μg/cm(2) and 12.0 μg/cm(2), respectively.

  12. STS-47 MS Davis and MS Jemison conduct LBNP experiment in the SLJ module

    NASA Technical Reports Server (NTRS)

    1992-01-01

    At the aft end of the Spacelab Japan (SLJ) science module, STS-47 Mission Specialist (MS) N. Jan Davis (foreground) readies Rack 9 Automatic Blood Pressure System (ABPS) controls as MS Mae C. Jemison, inside the cylindrical fabric lower body negative pressure (LBNP) device, waits for the LBNP experiment to begin. LBNP device is sealed around Jemison's waist. It is attached to the SLJ floor and has a controller that operates a pump to change the pressure inside. Davis will monitor Jemison's pulse rate, blood pressure, and cardiac dimensions and functions.

  13. STS-47 MS Davis and MS Jemison conduct LBNP experiment in the SLJ module

    NASA Technical Reports Server (NTRS)

    1992-01-01

    At the aft end of the Spacelab Japan (SLJ) science module, STS-47 Mission Specialist (MS) N. Jan Davis (foreground) readies Rack 9 Automatic Blood Pressure System (ABPS) controls as MS Mae C. Jemison, inside the cylindrical fabric lower body negative pressure (LBNP) device, waits for the LBNP experiment to begin. LBNP device is sealed around Jemison's waist. It is attached to the SLJ floor and has a controller that operates a pump to change the pressure inside. Davis will monitor Jemison's pulse rate, blood pressure, and cardiac dimensions and functions.

  14. STS-54 MS2 Harbaugh and MS3 Helms during slidewire egress training at KSC

    NASA Technical Reports Server (NTRS)

    1993-01-01

    STS-54 Endeavour, Orbiter Vehicle (OV) 105, Mission Specialist (MS2) Gregory J. Harbaugh (left) and MS3 Susan J. Helms, wearing launch and entry suits (LESs) and launch and entry helmets (LEHs), listen to instructions during emergency egress system (slidewire) training at a Kennedy Space Center (KSC) Launch Complex (LC) tower. The two crewmembers, positioned in a slidewire litter (basket), watch as Lockheed (Houston) technician Max Kandler, wearing stocking hat, performs final checks before sending them down the slidewire. The emergency egress training was part of the preflight terminal countdown demonstration tests (TCDTs).

  15. Quantitative analysis of methyl and propyl parabens in neonatal DBS using LC-MS/MS.

    PubMed

    Yakkundi, Shirish; Mulla, Hussain; Pandya, Hitesh; Turner, Mark A; McElnay, James

    2016-06-01

    Excipients are used to overcome the chemical, physical and microbiological challenges posed by developing formulated medicines. Both methyl and propyl paraben are commonly used in pediatric liquid formulations. There is no data on systemic exposure to parabens in neonates. The European Study of Neonatal Exposure to Excipients project has investigated this. Results & methodology: DBS sampling was used to collect opportunistic blood samples. Parabens were extracted from the DBS and analyzed using a validated LC-MS/MS assay. The above assay was applied to analyze neonatal DBS samples. The blood concentrations of parabens in neonates confirm systemic exposure to parabens following administration of routine medicines.

  16. STS-35 MS Hoffman and MS Parker on the middeck of Columbia, OV-102

    NASA Image and Video Library

    1990-12-10

    STS035-49-029 (2-10 Dec 1990) --- Posing on the middeck of Columbia, Orbiter Vehicle (OV) 102, are Mission Specialist (MS) Jeffrey A. Hoffman (mustache) and MS Robert A. R. Parker. Determining who is right side up is complicated by the microgravity of space. Hoffman's head is at the middeck floor and his feet are at the ceiling. The two crewmembers are in front of OV-102's port side with the waste collection system (WCS) contingency unit, side hatch, and galley visible behind them.

  17. Analysis of pesticide residues in strawberries and soils by GC-MS/MS, LC-MS/MS and two-dimensional GC-time-of-flight MS comparing organic and integrated pest management farming.

    PubMed

    Fernandes, Virgínia C; Lehotay, Steven J; Geis-Asteggiante, Lucía; Kwon, Hyeyoung; Mol, Hans G J; van der Kamp, Henk; Mateus, Nuno; Domingues, Valentina F; Delerue-Matos, Cristina

    2014-01-01

    This study analysed 22 strawberry and soil samples after their collection over the course of 2 years to compare the residue profiles from organic farming with integrated pest management practices in Portugal. For sample preparation, we used the citrate-buffered version of the quick, easy, cheap, effective, rugged, and safe (QuEChERS) method. We applied three different methods for analysis: (1) 27 pesticides were targeted using LC-MS/MS; (2) 143 were targeted using low pressure GC-tandem mass spectrometry (LP-GC-MS/MS); and (3) more than 600 pesticides were screened in a targeted and untargeted approach using comprehensive, two-dimensional gas chromatography time-of-flight mass spectrometry (GC × GC-TOF-MS). Comparison was made of the analyses using the different methods for the shared samples. The results were similar, thereby providing satisfactory confirmation of both similarly positive and negative findings. No pesticides were found in the organic-farmed samples. In samples from integrated pest management practices, nine pesticides were determined and confirmed to be present, ranging from 2 µg kg(-1) for fluazifop-p-butyl to 50 µg kg(-1) for fenpropathrin. Concentrations of residues in strawberries were less than European maximum residue limits.

  18. Identification of Bacteria Using Phylogenetic Relationships, Revealed by MS/MS Sequencing of Tryptic Peptides Derived from Cellular Proteins

    DTIC Science & Technology

    2004-11-17

    Universal Phylogenetic Tree of Bacteria Based on SSU rRNA Sequences Aquificae Termotogae Planctomycetes Actinobacteria Firmicutes Cyanobacteria...Identification of Bacteria Using Phylogenetic Relationships Revealed by MS/MS Sequencing of Tryptic Peptides Derived from Cellular Proteins Jacek P...Bacteria Using Phylogenetic Relationships Revealed by MS/MS Sequencing of Tryptic Peptides Derived from Cellular Proteins 5a. CONTRACT NUMBER 5b. GRANT

  19. ms_lims, a simple yet powerful open source laboratory information management system for MS-driven proteomics.

    PubMed

    Helsens, Kenny; Colaert, Niklaas; Barsnes, Harald; Muth, Thilo; Flikka, Kristian; Staes, An; Timmerman, Evy; Wortelkamp, Steffi; Sickmann, Albert; Vandekerckhove, Joël; Gevaert, Kris; Martens, Lennart

    2010-03-01

    MS-based proteomics produces large amounts of mass spectra that require processing, identification and possibly quantification before interpretation can be undertaken. High-throughput studies require automation of these various steps, and management of the data in association with the results obtained. We here present ms_lims (http://genesis.UGent.be/ms_lims), a freely available, open-source system based on a central database to automate data management and processing in MS-driven proteomics analyses.

  20. In vivo RNA labeling using MS2.

    PubMed

    Peña, Eduardo; Heinlein, Manfred; Sambade, Adrian

    2015-01-01

    The trafficking and asymmetric distribution of cytoplasmic RNA is a fundamental process during development and signaling across phyla. Plants support the intercellular trafficking of RNA molecules such as gene transcripts, small RNAs, and viral RNA genomes by targeting these RNA molecules to plasmodesmata (PD). Intercellular transport of RNA molecules through PD has fundamental implications in the cell-to-cell and systemic signaling during plant development and in the systemic spread of viral disease. Recent advances in time-lapse microscopy allow researchers to approach dynamic biological processes at the molecular level in living cells and tissues. These advances include the ability to label RNA molecules in vivo and thus to monitor their distribution and trafficking. In a broadly used RNA labeling approach, the MS2 method, the RNA of interest is tagged with a specific stem-loop (SL) RNA sequence derived from the origin of assembly region of the bacteriophage MS2 genome that binds to the bacteriophage coat protein (CP) and which, if fused to a fluorescent protein, allows the visualization of the tagged RNA by fluorescence microscopy. Here we describe a protocol for the in vivo visualization of transiently expressed SL-tagged RNA and discuss key aspects to study RNA localization and trafficking to and through plasmodesmata in Nicotiana benthamiana plants.

  1. Robert Carswell: the first illustrator of MS.

    PubMed

    Murray, T J

    2009-09-01

    The first illustration of multiple sclerosis (MS) was by a young Scottish physician and artist, Dr Robert Carswell. Recognized as a talented illustrator by his teachers, he was encouraged to create an anatomy and pathology atlas. He spent years in the hospitals and mortuaries of Paris and Lyon painting watercolours and pen and ink drawings of patients and post mortem preparations. Of the 1034 paintings, 99 are of the brain and spinal cord and Plate 4, figure 4.4 in the atlas (Figure 2), is of MS. Carswell indicated he saw two examples of this pathology, but had not examined either patient, but illustrated one of them. We know little about the clinical history other than that the patient was paralyzed. About 200 of the atlases were printed, and it is still regarded as one of the greatest and most beautiful of all medical books. Carswell was appointed as the first Professor of Anatomy at the North London Hospital, later renamed the University College Hospital UK, where the original copy of his great atlas is archived. Due to ill health he resigned after a few years to reside in the healthier air outside Brussels, Belgium. He was appointed physician to King Leopold, but was also noted for his care of the poor. Queen Victoria knighted him for his care of King Louis Philippe of France when he was in exile. Although English journals did not note his passing at the age of 64 years, his great atlas remains as his memorial.

  2. Quantification of phytoprostanes - bioactive oxylipins - and phenolic compounds of Passiflora edulis Sims shell using UHPLC-QqQ-MS/MS and LC-IT-DAD-MS/MS.

    PubMed

    Medina, Sonia; Collado-González, Jacinta; Ferreres, Federico; Londoño-Londoño, Julián; Jiménez-Cartagena, Claudio; Guy, Alexandre; Durand, Thierry; Galano, Jean-Marie; Gil-Izquierdo, Angel

    2017-08-15

    The genus Passiflora, comprising about 500 species, is the largest in the Passion flower family. Passiflora edulis Sims f. edulis (gulupa) is one of the most important fruits cultivated in Colombia. In recent years and due to its organoleptic and bioactive properties, its exports have significantly increased. In this work, six new bioactive oxylipins -phytoprostanes - were detected in gulupa shell by a UHPLC-QqQ-MS/MS method: F1t-phytoprostanes and D1t-phytoprostanes were the predominant and minor classes, respectively. Moreover, the polyphenol profile of the shell was investigated and we were able to detect and quantify phenolic compounds that have not been described previously, like luteolin-8-C-(2-O-rhamnosyl)hexoside and quercetin-3-O-(6″-acetyl)glucosyl-2″-sinapic acid. Consequently, this study provides new insights into the importance of gulupa shell as a valuable option in the design of new beverages rich in antioxidant phytochemicals, as part of a well-balanced diet, and in the process and quality control of such products. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. The comparison of glycosphingolipids isolated from an epithelial ovarian cancer cell line and a nontumorigenic epithelial ovarian cell line using MALDI-MS and MALDI-MS/MS.

    PubMed

    Rajanayake, Krishani K; Taylor, William R; Isailovic, Dragan

    2016-08-05

    Glycosphingolipids (GSLs) are important biomolecules, which are linked to many diseases such as GSL storage disorders and cancer. Consequently, the expression of GSLs may be altered in ovarian cancer cell lines in comparison to apparently healthy cell lines. Here, differential expressions of GSLs in an epithelial ovarian cancer cell line SKOV3 and a nontumorigenic epithelial ovarian cell line T29 were studied using matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS) and MALDI-MS/MS. The isolation of GSLs from SKOV3 and T29 cell lines was carried out using Folch partition. GSLs were successfully detected by MALDI-MS, and structurally assigned by a comparison of their MALDI-MS/MS fragmentation patterns with MS/MS data found in SimLipid database. Additionally, LIPID MAPS was used to assign GSL ion masses in MALDI-MS spectra. Seventeen neutral GSLs were identified in Folch partition lower (chloroform/methanol) phases originating from both cell lines, while five globo series neutral GSLs were identified only in the Folch partition lower phase of SKOV3 cell line. Several different sialylated GSLs were detected in Folch partition upper (water/methanol) phases of SKOV3 and T29 cell lines. Overall, this study demonstrates the alteration and increased glycosylation of GSLs in an epithelial ovarian cancer cell line in comparison to a nontumorigenic epithelial ovarian cell line.

  4. Measurement of unlabeled and stable isotope-labeled homoarginine, arginine and their metabolites in biological samples by GC-MS and GC-MS/MS.

    PubMed

    Kayacelebi, Arslan Arinc; Knöfel, Ann-Kathrin; Beckmann, Bibiana; Hanff, Erik; Warnecke, Gregor; Tsikas, Dimitrios

    2015-09-01

    Circulating and excretory L-homoarginine (hArg) and asymmetric dimethylarginine (ADMA) are cardiovascular risk factors. L-Arginine (Arg) is the common precursor of hArg and ADMA. This protocol describes gas chromatography-mass spectrometry (GC-MS) and gas chromatography-mass spectrometry-mass spectrometry (GC-MS/MS) methods for the quantitative determination of hArg, Arg and ADMA in biological samples, including human plasma, urine and sputum. Aliquots (10 µL) of native urine, plasma or serum ultrafiltrate (cutoff, 10 kDa), and acetone-deproteinized sputum samples are evaporated to dryness. Then, amino acids are derivatized to their methyl ester N-pentafluoropropionyl derivatives. In parallel, trideuteromethyl ester N-pentafluoropropionyl derivatives of hArg, Arg and ADMA are de novo synthesized from the unlabelled amino acids and used as internal standards. Alternatively, commercially available stable isotope-labeled analogs of hArg, Arg and ADMA are used as internal standards, and they are added to the native biological samples. Quantification is performed by selected ion monitoring in GC-MS and selected reaction monitoring in GC-MS/MS. By these protocols, unlabelled and stable isotope-labeled hArg, Arg and their metabolites including ADMA and ornithine can be measured equally accurately and precisely by GC-MS and GC-MS/MS in several different biological fluids in experimental and clinical settings.

  5. ANALYSIS OF DISINFECTION BY-PRODUCTS IN DRINKING WATER BY LC-MS AND RELATED MS TECHNIQUES

    EPA Science Inventory

    This review covers recent applications of LC/MS and other related techniques such as flow injection-atmospheric pressure chemical ionization and electrospray ionization-MS, high-field asymmetric waveform ion mobility spectrometry-electrospray ionization-MS, membrane introduction ...

  6. VOC identification and inter-comparison from laboratory biomass burning using PTR-MS and PIT-MS

    Treesearch

    C. Warneke; J. M. Roberts; P. Veres; J. Gilman; W. C. Kuster; I. Burling; R. Yokelson; J. A. de Gouw

    2011-01-01

    Volatile organic compounds (VOCs) emitted from fires of biomass commonly found in the southeast and southwest U.S. were investigated with PTR-MS and PIT-MS, which are capable of fast measurements of a large number of VOCs. Both instruments were calibrated with gas standards and mass dependent calibration curves are determined. The sensitivity of the PIT-MS linearly...

  7. Identification of monomenthyl succinate in natural mint extracts by LC-ESI-MS-MS and GC-MS.

    PubMed

    Marin, Christophe; Schippa, Christine

    2006-06-28

    Fresh and dried mint leaves Mentha piperita (peppermint) and Mentha spicata (spearmint) were extracted in two different ways and the extracts investigated by high performance liquid chromatography-tandem mass spectrometry. All the ethanolic extracts prepared with Soxhlet apparatus were used in the identification of monomenthyl succinate as previously reported. The highest level was found in fresh spearmint leaves. The analysis of the extractions, prepared under mild conditions using a fluorinated solvent (HFC 134-a), confirmed the natural occurrence of monomenthyl succinate in the leaves, ruling out the hypothesis that this constituent could be an artifact of the Soxhlet extraction process. A method for identifying this compound in such a fluorinated solvent extract of mint leaf using preliminary esterification with diazomethane and then GC-MS is described.

  8. 3D imaging of biological specimen using MS.

    PubMed

    Fletcher, John S

    2015-01-01

    Imaging MS can provide unique information about the distribution of native and non-native compounds in biological specimen. MALDI MS and secondary ion MS are the two most commonly applied imaging MS techniques and can provide complementary information about a sample. MALDI offers access to high mass species such as proteins while secondary ion MS can operate at higher spatial resolution and provide information about lower mass species including elemental signals. Imaging MS is not limited to two dimensions and different approaches have been developed that allow 3D molecular images to be generated of chemicals in whole organs down to single cells. Resolution in the z-dimension is often higher than in x and y, so such analysis offers the potential for probing the distribution of drug molecules and studying drug action by MS with a much higher precision - possibly even organelle level.

  9. Identification of hormone esters in injection site in muscle tissues by LC/MS/MS.

    PubMed

    Costain, R M; Fesser, A C E; McKenzie, D; Mizuno, M; MacNeil, J D

    2008-12-01

    The detection of hormone abuse for growth promotion in food animal production is a global concern. Initial testing for hormones in Canada was directed at the compounds approved for use in beef cattle, melengestrol acetate, trenbolone acetate and zeranol, and the banned compound diethylstilbestrol (DES). No hormonal growth promoters are approved for use in veal production in Canada. However, instances of use of trenbolone and clenbuterol were detected in Canada in the 1990s. During the development of a new analytical method for testosterone and progesterone, there were reports of suspicious injection sites being found in veal calves. Upon implementation of the method, analysis of investigative samples revealed significant residues of testosterone in some injection sites. To prove that the source of these residues was exogenous, a fully validated method for hormone esters was developed to confirm the presence of exogenous hormones in these injection sites. The QUECHERS model was employed in methods development and resulted in a simple, effective extraction technique that consisted of sample pre-homogenization, liquid/liquid partitioning, extract dilution, filtration and use of LC/MS/MS to provide detection selectivity. The result was an adaptable MS/MS confirmation technique that meets the needs of Canadian regulatory authorities to confirm the misuse of injectable testosterone, and potentially other hormones, in food animal production.

  10. Peptide rearrangement during quadrupole ion trap fragmentation: added complexity to MS/MS spectra.

    PubMed

    Yagüe, Jesús; Paradela, Alberto; Ramos, Manuel; Ogueta, Samuel; Marina, Anabel; Barahona, Fernando; López de Castro, José A; Vázquez, Jesús

    2003-03-15

    The emergence of proteomics has placed great interest in the understanding of the mechanisms of MS/MS fragmentation of peptides under low-energy collision-induced dissociation. In this work, we describe the presence of anomalous fragments, which correspond to neutral loss elimination of internal amino acids from ions of the b series in quadrupole ion trap MS/MS spectra from naturally occurring peptides. Internal amino acid elimination occurred preferentially with aliphatic amino acids. The phenomenon was more apparent when doubly charged precursors were fragmented and was inhibited when peptides were N-acetylated at the N-terminus. Fragmentation of isomeric peptides where some internal amino acids were relocated in N-terminal position produced MSn spectra indistinguishable from those of the original peptides, indicating that some b ions underwent a structural rearrangement process. Formation of anomalous fragments required a minimum activation time. Our data are consistent with a nucleophile attack of the N-terminal nitrogen over the electrophilic carbonyl carbon at one peptide bond, forming a cyclic b ion intermediate that, by reopening at preferential sites, exposes internal amino acids to the C-terminal side.

  11. LC/MS/MS for identification of in vivo and in vitro metabolites of jatrorrhizine.

    PubMed

    Zhang, Yi; Wu, Wenhua; Han, Fengmei; Chen, Yong

    2008-12-01

    The in vivo and in vitro metabolism of jatrorrhizine has been investigated using a specific and sensitive LC/MS/MS method. In vivo samples including rat feces, urine and plasma collected separately after dosing healthy rats with jatrorrhizine (34 mg/kg) orally, along with in vitro samples prepared by incubating jatrorrhizine with rat intestinal flora and liver microsome, respectively, were purified using a C(18) solid-phase extraction cartridge. The purified samples were then separated with a reversed-phase C(18) column with methanol-formic acid aqueous solution (70:30, v/v, pH3.5) as mobile phase and detected by on-line MS/MS. The structural elucidation of the metabolites was performed by comparing their molecular weights and product ions with those of the parent drug. As a result, seven new metabolites were found in rat urine, 13 metabolites were detected in rat feces, 11 metabolites were detected in rat plasma, 17 metabolites were identified in intestinal flora incubation solution and nine metabolites were detected in liver microsome incubation solution. The main biotransformation reactions of jatrorrhizine were the hydroxylation reaction, the methylation reaction, the demethylation reaction and the dehydrogenation reaction of parent drug and its relative metabolites. All the results were reported for the first time, except for some of the metabolites in rat urine.

  12. MALDI MSI and LC-MS/MS: Towards preclinical determination of the neurotoxic potential of fluoroquinolones.

    PubMed

    Shobo, Adeola; Baijnath, Sooraj; Bratkowska, Dominika; Naiker, Suhashni; Somboro, Anou M; Bester, Linda A; Singh, Sanil D; Naicker, Tricia; Kruger, Hendrik G; Govender, Thavendran

    2016-08-01

    Fluoroquinolones are broad-spectrum antibiotics with efficacy against a wide range of pathogenic microbes associated with respiratory and meningeal infections. The potential toxicity of this class of chemical agents is a source of major concern and is becoming a global issue. The aim of this study was to develop a method for the brain distribution and the pharmacokinetic profile of gatifloxacin in healthy Sprague-Dawley rats, via Multicenter matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI MSI) and quantitative liquid chromatography-tandem mass spectrometry (LC-MS/MS). We developed a sensitive LC-MS/MS method to quantify gatifloxacin in plasma, lung, and brain homogenates. A pharmacokinetic profile was observed where there is a double peak pattern; a sharp initial increase in the concentration soon after dosing followed by a steady decline until another increase in concentration after a longer period post dosing in all three biological samples was observed. The imaging results showed the drug gradually entering the brain via the blood brain barrier and into the cortical regions from 15 to 240 min post dose. As time elapses, the drug leaves the brain following the same path as it followed on its entry and finally concentrates at the cortex. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  13. Multiclass determination and confirmation of antibiotic residues in honey using LC-MS/MS.

    PubMed

    Lopez, Mayda I; Pettis, Jeffery S; Smith, I Barton; Chu, Pak-Sin

    2008-03-12

    A multiclass method has been developed for the determination and confirmation in honey of tetracyclines (chlortetracycline, doxycycline, oxytetracycline, and tetracycline), fluoroquinolones (ciprofloxacin, danofloxacin, difloxacin, enrofloxacin, and sarafloxacin), macrolides (tylosin), lincosamides (lincomycin), aminoglycosides (streptomycin), sulfonamides (sulfathiazole), phenicols (chloramphenicol), and fumagillin residues using liquid chromatography tandem mass spectrometry (LC-MS/MS). Erythromycin (a macrolide) and monensin (an ionophore) can be detected and confirmed but not quantitated. Honey samples (approximately 2 g) are dissolved in 10 mL of water and centrifuged. An aliquot of the supernatant is used to determine streptomycin. The remaining supernatant is filtered through a fine-mesh nylon fabric and cleaned up by solid phase extraction. After solvent evaporation and sample reconstitution, 15 antibiotics are assayed by LC-MS/MS using electrospray ionization (ESI) in positive ion mode. Afterward, chloramphenicol is assayed using ESI in negative ion mode. The method has been validated at the low part per billion levels for most of the drugs with accuracies between 65 and 104% and coefficients of variation less than 17%. The evaluation of matrix effects caused by honey of different floral origin is presented.

  14. Determination of residual fipronil in chicken egg and muscle by LC-MS/MS.

    PubMed

    Zhang, Meiyu; Bian, Kui; Zhou, Tong; Song, Xuqin; Liu, Qingying; Meng, Chenying; He, Limin

    2016-03-01

    A simple, sensitive and reliable method was developed and applied to the residue analysis of fipronil in chicken egg and muscle by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Chicken egg and muscle samples were extracted with acetronitrile, then salting out by dehydration with anhydrous magnesium sulfate and sodium chloride. The extracts were purified by the C18 solid phase extraction cartridge prior to analysis by LC-MS/MS. The matrix-matched calibration curve showed a good linear within the concentration range from 0.01 to 2.00μgkg(-1) (r(2)≥0.999). The average recoveries of fipronil at three spiked levels of 0.01, 0.1 and 1.0μgkg(-1) ranged from 79.7% to 98.0%, and the relative standard deviations were less than 8.8%. The decision limit (CCα) and detection capability (CCβ) of fipronil in chicken egg and muscle matrices were all 0.002μgkg(-1) and 0.01μgkg(-1), respectively. The method has also been successfully applied to monitoring fipronil in the real samples. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Simultaneous inhibition assay for human and microbial kinases via MALDI-MS/MS.

    PubMed

    Smith, Anne Marie E; Brennan, John D

    2014-03-03

    Selective inhibition of one kinase over another is a critical issue in drug development. For antimicrobial development, it is particularly important to selectively inhibit bacterial kinases, which can phosphorylate antimicrobial compounds such as aminoglycosides, without affecting human kinases. Previous work from our group showed the development of a MALDI-MS/MS assay for the detection of small molecule modulators of the bacterial aminoglycoside kinase APH3'IIIa. Herein, we demonstrate the development of an enhanced kinase MALDI-MS/MS assay involving simultaneous assaying of two kinase reactions, one for APH3'IIIa, and the other for human protein kinase A (PKA), which leads to an output that provides direct information on selectivity and mechanism of action. Specificity of the respective enzyme substrates were verified, and the assay was validated through generation of Z'-factors of 0.55 for APH3'IIIa with kanamycin and 0.60 for PKA with kemptide. The assay was used to simultaneously screen a kinase-directed library of mixtures of ten compounds each against both enzymes, leading to the identification of selective inhibitors for each enzyme as well as one non-selective inhibitor following mixture deconvolution.

  16. Potential Health Benefits and Metabolomics of Camel Milk by GC-MS and ICP-MS.

    PubMed

    Ahamad, Syed Rizwan; Raish, Mohammad; Ahmad, Ajaz; Shakeel, Faiyaz

    2017-02-01

    None of the research reports reveals the metabolomics and elemental studies on camel milk. Recent studies showed that camel milk possesses anticancer and anti-inflammatory activity. Metabolomics and elemental studies were carried out in camel milk which showed us the pathways and composition that are responsible for the key biological role of camel milk. Camel milk was dissolved in methanol and chloroform fraction and then vortexed and centrifuged. Both the fractions were derivatized by N,O-bis-(trimethylsilyl)trifluoroacetamide (BSTFA) and TMCS after nitrogen purging and analyzed by GC-MS. Camel milk was also analyzed by ICP-MS after microwave digestion. We found that higher alkanes and fatty acids are present in the chloroform fraction and amino acids, sugars and fatty acid derivatives are present in aqueous fractions. All the heavy metals like As, Pb, Cd, Co, Cu, and Ni were in the safe limits in terms of maximum daily intake of these elements. Na, K, Mg, and Ca were also present in the safe limits in terms of maximum daily intake of these elements. These results suggested that the camel milk drinking is safe and there is no health hazard. The present data of GC-MS and ICP-MS correlate the activities related to camel milk.

  17. Global metabolite profiling of human colorectal cancer xenografts in mice using HPLC-MS/MS.

    PubMed

    Loftus, Neil J; Lai, Lindsay; Wilkinson, Robert W; Odedra, Rajesh; Wilson, Ian D; Barnes, Alan J

    2013-06-07

    Reversed-phase gradient LC-MS was used to perform untargeted metabonomic analysis on extracts of human colorectal cancer (CRC) cell lines (COLO 205, HT-29, HCT 116 and SW620) subcutaneously implanted into age-matched athymic nude male mice to study small molecule metabolic profiles and examine possible correlations with human cancer biopsies. Following high mass accuracy data analysis using MS and MS/MS, metabolites were identified by searching against major metabolite databases including METLIN, MASSBANK, The Human Metabolome Database, PubChem, Biospider, LipidMaps and KEGG. HT-29 and COLO 205 tumor xenografts showed a distribution of metabolites that differed from SW620 and HCT 116 xenografts (predominantly on the basis of relative differences in the amounts of amino acids and lipids detected). This finding is consistent with NMR-based analysis of human colorectal tissue, where the metabolite profiles of HT-29 tumors exhibit the greatest similarity to human rectal cancer tissue with respect to changes in the relative amounts of lipids and choline-containing compounds. As the metabolic signatures of cancer cells result from oncogene-directed metabolic reprogramming, the HT-29 xenografts in mice may prove to be a useful model to further study the tumor microenvironment and cancer biology.

  18. Simultaneous assessment of endogenous thiol compounds by LC-MS/MS.

    PubMed

    Sun, Yao; Yao, Tong; Guo, Xiucai; Peng, Ying; Zheng, Jiang

    2016-09-01

    Biological thiol compounds are very important molecules that participate in various physiological events. Alteration in levels of endogenous thiols has been suggested as a biomarker of early stage of pathological changes. We reported a chemical derivatization- and LC-MS/MS-based approach to simultaneously determine thiol compounds including glutathione (GSH), cysteine (Cys), N-acetyl cysteine (NAC), homocysteine (Hcy), and cysteinylglycine (CysGly) in biological samples. Thiol-containing samples were derivatized with monobromobimane (mBrB) at room temperature, followed by LC-MS/MS analysis. Assessment of the analytes with baseline separation was completed within 10min, using a gradient elution on a C18 reversed-phase column. Excellent linearity was observed for all analytes over their concentration ranges of 1-400μM. The lowest limits of detection (S/N=3) in a range from 0.31fmol (for NAC) to 4.98fmol (for CysGly) were achieved. The results indicate that this approach was sensitive, selective, and well suited for high-throughput quantitative determination of the biological thiols.

  19. Performance characteristics of an LC-MS/MS method for the determination of plasma metanephrines.

    PubMed

    Petteys, Brian J; Graham, Kendon S; Parnás, M Laura; Holt, Crystal; Frank, Elizabeth L

    2012-10-09

    Catecholamines and their metabolites, metanephrines, are produced excessively in pheochromocytoma tumors of the chromaffin cells. Increased concentrations of these compounds produce symptoms and allow for clinical evaluation of disease. Historically, screening for such tumors by determination of catecholamines and metabolites in urine yielded false negative results in individuals with a genetic predisposition for the disease and those with paroxysmal hypertension. Analysis of metanephrines in plasma, however, is of decisive diagnostic importance. This test exhibits high sensitivity and specificity for the analytes produced by tumors. Plasma proteins are removed by solid phase extraction. Chromatographic isolation of the analytes and stable isotope internal standards is achieved by elution on a HILIC column connected to a UPLC MS/MS system. Metanephrines are measured using multiple reaction monitoring with an electrospray source operating in positive ion mode. The method was validated for linearity, limit of quantification, accuracy, and precision. The method was accurate and correlated well to a comparison HPLC method. Potential interferences were evaluated. Results from this LC-MS/MS assay enable clinical diagnosis of pheochromocytoma and aid in monitoring treatment outcomes. Copyright © 2012 Elsevier B.V. All rights reserved.

  20. Pharmacokinetics of Dibutyl Phthalate (DBP) in the Rat Determined by UPLC-MS/MS

    PubMed Central

    Chang, Li-Wen; Hou, Mei-Ling; Tsai, Tung-Hu

    2013-01-01

    Dibutyl phthalate (DBP) is commonly used to increase the flexibility of plastics in industrial products. However, several plasticizers have been illegally used as clouding agents to increase dispersion of aqueous matrix in beverages. This study thus develops a rapid and validated analytical method by ultra-performance liquid chromatography with tandem mass spectrometry (UPLC-MS/MS) for the evaluation of pharmacokinetics of DBP in free moving rats. The UPLC-MS/MS system equipped with positive electrospray ionization (ESI) source in multiple reaction monitoring (MRM) mode was used to monitor m/z 279.25→148.93 transitions for DBP. The limit of quantification for DBP in rat plasma and feces was 0.05 μg/mL and 0.125 μg/g, respectively. The pharmacokinetic results demonstrate that DBP appeared to have a two-compartment model in the rats; the area under concentration versus time (AUC) was 57.8 ± 5.93 min μg/mL and the distribution and elimination half-life (t1/2,α and t1/2,β) were 5.77 ± 1.14 and 217 ± 131 min, respectively, after DBP administration (30 mg/kg, i.v.). About 0.18% of the administered dose was recovered from the feces within 48 h. The pharmacokinetic behavior demonstrated that DBP was quickly degraded within 2 h, suggesting a rapid metabolism low fecal cumulative excretion in the rat. PMID:23344044

  1. UP-HILIC-MS/MS to Determine the Action Pattern of Penicillium sp. Dextranase

    NASA Astrophysics Data System (ADS)

    Yi, Lin; Sun, Xue; Du, Kenze; Ouyang, Yilan; Wu, Chengling; Xu, Naiyu; Linhardt, Robert J.; Zhang, Zhenqing

    2015-07-01

    Investigation of the action pattern of enzymes acting on carbohydrates is challenging, as both the substrate and the digestion products are complex mixtures. Dextran and its enzyme-derived oligosaccharides are widely used for many industrial applications. In this work, a new method relying on ultra-performance hydrophilic interaction liquid chromatography quadrupole time-of-flight tandem mass spectrometry (UP-HILIC- Q/TOF-MS/MS) was developed to analyze a complex mixture of dextran oligosaccharide products to determine the action pattern of dextranase. No derivatization of oligosaccharides was required and the impact of the α- and β-configurations of the native oligosaccharides on the chromatographic separation was eliminated. The 1→6, 1→3, 1→4 backbone linkages and the branch linkages of these oligosaccharides were all distinguished from diagnostic ions in their MS/MS spectra, including fragments corresponding to 0,2A, 0,3A, 0,4A, B-H2O, 2,5A, and 3,5A. The sequences of the oligosaccharide products were similarly established. Thus, the complex oligosaccharide mixtures in dextran digestion products were profiled and identified using this method. The more enzyme-resistant structures in dextran were established using much less sample, labor, time, and uncertainty than in previous studies. This method provides an efficient, sensitive, and straightforward way to monitor the entire process of digestion, establish the action pattern of the dextranase from Penicillium sp., and to support the proper industrial application of dextranase.

  2. Ultrafast quantification of β-lactam antibiotics in human plasma using UPLC-MS/MS.

    PubMed

    Carlier, Mieke; Stove, Veronique; De Waele, Jan J; Verstraete, Alain G

    2015-01-26

    There is an increasing interest in monitoring plasma concentrations of β-lactam antibiotics. The objective of this work was to develop and validate a fast ultra-performance liquid chromatographic method with tandem mass spectrometric detection (UPLC-MS/MS) for simultaneous quantification of amoxicillin, cefuroxime, ceftazidime, meropenem and piperacillin with minimal turn around time. Sample clean-up included protein precipitation with acetonitrile containing 5 deuterated internal standards, and subsequent dilution of the supernatant with water after centrifugation. Runtime was only 2.5 min. Chromatographic separation was performed on a Waters Acquity UPLC system using a BEH C18 column (1.7 μm, 100 mm × 2.1 mm) applying a binary gradient elution of water and methanol both containing 0.1% formic acid and 2 mmol/L ammonium acetate on a Water TQD instrument in MRM mode. All compounds were detected in electrospray positive ion mode and could be quantified between 1 and 100 mg/L for amoxicillin and cefuroxime, between 0.5 and 80 mg/L for meropenem and ceftazidime, and between 1 and 150 mg/L for piperacillin. The method was validated in terms of precision, accuracy, linearity, matrix effect and recovery and has been compared to a previously published UPLC-MS/MS method.

  3. Girard derivatization for LC-MS/MS profiling of endogenous ecdysteroids in Drosophila[S

    PubMed Central

    Lavrynenko, Oksana; Nedielkov, Ruslan; Möller, Heiko M.; Shevchenko, Andrej

    2013-01-01

    Ecdysteroids are potent developmental regulators that control molting, reproduction, and stress response in arthropods. In developing larvae, picogram quantities of individual ecdysteroids and their conjugated forms are present along with milligrams of structural and energy storage lipids. To enhance the specificity and sensitivity of ecdysteroid detection, we targeted the 6-ketone group, which is common to all ecdysteroids, with Girard reagents. Unlike other ketosteroids, during the reaction, Girard hydrazones of ecdysteroids eliminated the C14-hydroxyl group, creating an additional C14-C15 double bond. Dehydrated hydrazones of endogenous ecdysteroids were detected by LC-MS/MS in the multiple reaction monitoring (MRM) mode using two mass transitions: one relied upon neutral loss of a quaternary amine from the Girard T moiety; another complementary transition followed neutral loss of the hydrocarbon chain upon C20-C27 cleavage. We further demonstrated that a combination of Girard derivatization and LC-MS/MS enabled unequivocal detection of three major endogenous hormones at the picogram level in an extract from a single Drosophila pupa. PMID:23843360

  4. Validation of an HPLC-MS/MS and Wipe Procedure for Mitomycin C Contamination

    PubMed Central

    B’Hymer, C.; Connor, T.H.; Stinson, D.; Pretty, J.R.

    2015-01-01

    A high-performance liquid chromatography-tandem mass spectrometric (HPLC-MS/MS) method was developed for the determination of mitomycin C, an anticancer drug, from contamination on various surfaces. Mitomycin C is often used in various forms of intraperitoneal chemotherapy, and operating room healthcare worker exposure to this drug is possible. The surface testing method consisted of a wiping procedure utilizing a solution of 20/45/35 (v/v/v) of acetonitrile-isopropanol-water made 0.01 M in ammonium citrate (apparent pH 7.0). The wipe solutions were analyzed by means of HPLC-MS/MS using a reversed-phase gradient system and electrospray ionization in positive ion-mode with a triple-quadrupole mass spectrometric detector. Accuracy and precision of this method were demonstrated by a series of recovery studies of both spiked solutions and extracted wipes from various surfaces (stainless steel, vinyl and Formica®) spiked with known levels of mitomycin C. Recoveries of spiked solutions containing the analyte demonstrate mean recoveries (accuracy) ranged from 93 to 105%. Precision as measured by the relative standard deviation (%RSD) of multiple samples (n=10) at each concentration level demonstrated values of 7.5% or less. The recoveries from spiked surfaces varied from 30 to 99%. The limit of detection (LOD) for this methodology is approximately 2 ng/100 cm2 equivalent surface area, and the limit of quantitation (LOQ) is approximately 6 ng/100 cm2. PMID:25129062

  5. Advances in the quantitation of therapeutic insulin analogues by LC-MS/MS.

    PubMed

    Blackburn, Michael

    2013-12-01

    Insulin analogues represent a major and growing class of biotherapeutics, and their quantitation is an important focus of commercial and public effort across a number of different fields. As LC-MS has developed, it has become an increasingly practicable and desirable alternative to ligand-binding-based approaches for quantitation of this class of compounds. The sensitivity challenge of measuring trace levels of this large peptide molecule in a protein-containing matrix is considerable; however, different approaches to detection, extraction and separation are described to overcome this challenge, including immunoaffinity capture, SPE and low-flow HPLC. Considerations such as bioanalytical assay acceptance criteria and antidrug antibody effects during drug development are included, alongside descriptions of recent sports doping and clinical applications. Factors affecting the correlation and agreement of MS with biological ligand-binding methods are discussed, with ways to anticipate and appreciate differences between the values derived from each technique. The 'future perspective' section discusses the likely trend towards MS-based analysis for these compounds and the impact of HRMS. A high degree of scientific creativity, combined with science-defined regulatory approaches that define suitable validation criteria, will be needed to meet the demanding requirements for high-throughput analysis of insulin by LC-MS.

  6. LC-MS-MS Method for Analysis of Benzodiazepines in Wastewater During Football Games IV.

    PubMed

    Stamper, Brandon; Gul, Waseem; Godfrey, Murrell; Gul, Shahbaz W; ElSohly, Mahmoud A

    2017-04-01

    Continuing our studies for the analyses of drugs of abuse in municipal wastewater, a method was developed for the analysis of benzodiazepines in wastewater samples using liquid chromatography coupled with tandem mass spectrometry (LC-MS-MS). Ten benzodiazepines and metabolites were analyzed (structures were found), including alprazolam, α-OH-alprazolam (the primary urinary metabolite of alprazolam), chlordiazepoxide, flurazepam, 2-OH-ethylflurazepam (the primary urinary metabolite of flurazepam), 7-NH2-flunitrazepam, nordiazepam, oxazepam, temazepam and α-OH-triazolam (the primary urinary metabolite of triazolam) (representative chromatograms were found). These drugs were chosen because of their widespread abuse. Wastewater samples were collected at both the Oxford Wastewater Treatment Plant (WWTP) in Oxford, Mississippi (MS) and the University WWTP in University, MS. These wastewater samples were collected on weekends in which the Ole Miss Rebel football team held home games at the Vaught-Hemingway Stadium, University, and one weekend on which there was no game. The collected samples were analyzed using a validated method and found to contain alprazolam, α-OH-alprazolam, nordiazepam, oxazepam and temazepam. None of the samples contained chlordiazepoxide, flurazepam, 2-hydroxyethyl-flurazepam, 7-NH2-flunitrazepam and α-OH-triazolam. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  7. LC-MS/MS Identification of a Bromelain Peptide Biomarker from Ananas comosus Merr

    PubMed Central

    Secor, Eric R.; Szczepanek, Steven M.; Singh, Anurag; Guernsey, Linda; Natarajan, Prabitha; Rezaul, Karim; Han, David K.; Thrall, Roger S.; Silbart, Lawrence K.

    2012-01-01

    Bromelain (Br) is a cysteine peptidase (GenBank AEH26024.1) from pineapple, with over 40 years of clinical use. The constituents mediating its anti-inflammatory activity are not thoroughly characterized and no peptide biomarker exists. Our objective is to characterize Br raw material and identify peptides in the plasma of Br treated mice. After SDS-PAGE in-gel digestion, Br (VN#3507; Middletown, CT, USA) peptides were analyzed via LC/MS/MS using 95% protein probability, 95% peptide probability, and a minimum peptide number = 5. Br spiked mouse plasma (1 ug/ul) and plasma from i.p. treated mice (12 mg/kg) were assessed using SRM. In Br raw material, we identified seven proteins: four proteases, one jacalin-like lectin, and two protease inhibitors. In Br spiked mouse plasma, six proteins (ananain, bromelain inhibitor, cysteine proteinase AN11, FB1035 precursor, FBSB precursor, and jacalin-like lectin) were identified. Using LC/MS/MS, we identified the unique peptide, DYGAVNEVK, derived from FB1035, in the plasma of i.p. Br treated mice. The spectral count of this peptide peaked at 6 hrs and was undetectable by 24 hrs. In this study, a novel Br peptide was identified in the plasma of treated mice for the first time. This Br peptide could serve as a biomarker to standardize the therapeutic dose and maximize clinical utility. PMID:23082082

  8. Determination of trace levels of aquaculture chemotherapeutants in seawater samples by SPME-GC-MS/MS.

    PubMed

    García-Rodríguez, Diego; Carro, Antonia M; Lorenzo, Rosa A; Fernández, Fátima; Cela, Rafael

    2008-08-01

    A sensitive and efficient solid-phase microextraction (SPME) method for the determination of organophosphorous (OPPs) and pyrethroid pesticides (Pyrs) in aquaculture-seawater samples by using GC with MS/MS (GC-MS/MS) was developed. Dichlorvos and chlorpyrifos (OPPs); permethrin, alpha-cypermethrin and deltamethrin (Pyrs) were selected according to their use as chemotherapeutants in the aquaculture industry. Different parameters affecting extraction efficiency such as fibre coating, agitation, pH and extraction time profiles were investigated. An experimental central composite design (alpha = 1) and desirability functions were used for the simultaneous optimization of extraction temperature and sample volume. Finally, a method based on direct SPME in 40 min at 75 degrees C using 100-microm-thick poly(dimethyl)siloxane (PDMS) fibre and 20 mL of sample volume is proposed. The method was validated, exhibiting good linearity, precision and accuracy parameters with picogram per millilitre LODs. The proposed methodology was applied to determine the ultratrace levels of OPPs and Pyrs in aquaculture-seawater samples by the standard addition approach, which proved to be reliable and sensitive, in addition to requiring only small amounts of sample.

  9. Determination and confirmation of nitrofuran residues in honey using LC-MS/MS.

    PubMed

    Lopez, Mayda I; Feldlaufer, Mark F; Williams, Anthony D; Chu, Pak-Sin

    2007-02-21

    A method was developed for the determination and confirmation of furazolidone, nitrofurazone, furaltadone, and nitrofurantoin as their side-chain residues in honey using liquid chromatography-tandem mass spectrometry (LC-MS/MS). An initial solid-phase extraction cleanup of the honey samples was followed by overnight hydrolysis and derivatization of the nitrofuran side-chain residues with 2-nitrobenzaldehyde. After pH adjustment and liquid-liquid extraction, the extracts were assayed by LC-MS/MS using electrospray ionization in the positive ion mode. The method was validated at concentrations ranging from 0.5 to 2.0 ppb with accuracies of 92-103% and coefficients of variation of < or =10%. The lowest calibration standard used (0.25 ppb) was defined as the limit of quantitation for all four nitrofuran side-chain residues. The extracts and standards were also used for confirmatory purposes. Honey from dosed beehives was assayed to study the stability of the nitrofuran residues and to demonstrate the effectiveness of the method.

  10. Application of LC-MS/MS MRM to Determine Staphylococcal Enterotoxins (SEB and SEA) in Milk.

    PubMed

    Andjelkovic, Mirjana; Tsilia, Varvara; Rajkovic, Andreja; De Cremer, Koen; Van Loco, Joris

    2016-04-20

    Staphylococcus aureus is one of the important aetiological agents of food intoxications in Europe and can cause gastro-enteritis through the production of various staphylococcal enterotoxins (SEs) in foods. Due to their stability and ease of production and dissemination, some SEs have also been studied as potential agents for bioterrorism. Therefore, specific and accurate analytical tools are required to detect and quantify SEs. Online solid-phase extraction liquid chromatography electrospray ionization tandem mass spectrometry (online SPE-LC-ESI-MS/MS) based on multiple reaction monitoring (MRM) was used to detect and quantify two types of SE (A and B) spiked in milk and buffer solution. SE extraction and concentration was performed according to the European Screening Method developed by the European Reference Laboratory for Coagulase Positive Staphylococci. Trypsin digests were screened for the presence of SEs using selected proteotypic heavy-labeled peptides as internal standards. SEA and SEB were successfully detected in milk samples using LC-MS/MS in MRM mode. The selected SE peptides were proteotypic for each toxin, allowing the discrimination of SEA and SEB in a single run. The detection limit of SEA and SEB was approximately 8 and 4 ng/g, respectively.

  11. Automated saliva processing for LC-MS/MS: Improving laboratory efficiency in cortisol and cortisone testing.

    PubMed

    Antonelli, Giorgia; Padoan, Andrea; Artusi, Carlo; Marinova, Mariela; Zaninotto, Martina; Plebani, Mario

    2016-04-01

    The aim of this study was to implement in our routine practice an automated saliva preparation protocol for quantification of cortisol (F) and cortisone (E) by LC-MS/MS using a liquid handling platform, maintaining the previously defined reference intervals with the manual preparation. Addition of internal standard solution to saliva samples and calibrators and SPE on μ-elution 96-well plate were performed by liquid handling platform. After extraction, the eluates were submitted to LC-MS/MS analysis. The manual steps within the entire process were to transfer saliva samples in suitable tubes, to put the cap mat and transfer of the collection plate to the LC auto sampler. Transference of the reference intervals from the manual to the automated procedure was established by Passing Bablok regression on 120 saliva samples analyzed simultaneously with the two procedures. Calibration curves were linear throughout the selected ranges. The imprecision ranged from 2 to 10%, with recoveries from 95 to 116%. Passing Bablok regression demonstrated no significant bias. The liquid handling platform translates the manual steps into automated operations allowing for saving hands-on time, while maintaining assay reproducibility and ensuring reliability of results, making it implementable in our routine with the previous established reference intervals. Copyright © 2015 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  12. [Simultaneous determination of adrenaline, noradrenaline, cortisone and cortisol in plasma with HPLC/MS/MS].

    PubMed

    Yong, Li; Wang, Yu; Zou, Xiao-Li; Zhu, Lan; Xie, Hui-Ru; Li, Long-Jiang

    2014-01-01

    To develop a method for simultaneous determination of adrenaline, noradrenaline, cortisone and cortisol in plasma using HPLC/MS/MS. Sample proteins were precipitated with acetonitrile and the sample solution was injected into HPLC/MS/MS after centrifugation at 15,000 r/min for 5 min. Electrospray ionization (ESI) and the positive ion detection were applied with a multiple reaction monitoring (MRM) mode for quantitative analyses. Under the optimal conditions, good linearity (r > 0.999) was observed in the range of 0.02-200.00 ng/mL of target compounds. The detection limit reached 4.13 pg/mL, 4.64 pg/mL, 4.29 pg/mL and 4.52 pg/mL for adrenaline, noradrenaline, cortisone and cortisol respectively. The inter-day and intra-day precisions ranged from 1.19%-5.42% and 2.16%-6.04% respectively. Satisfied results were achieved using human plasma samples, with a spiked recovery in the range of 80.0%-109.0% and a relative standard deviation of 3.93%-7.57%. The proposed method is quick, sensitive and suitable for batch analyses of plasma samples.

  13. Analysis of six relevant toxaphene congeners in biological samples using ion trap MS/MS.

    PubMed

    Gouteux, Bruno; Lebeuf, Michel; Trottier, Steve; Gagné, Jean-Pierre

    2002-10-01

    The quantification of six polychlorinated bornanes (CHBs) was studied using ion trap MS/MS. The significance of the selection of parent ions (Ip) and daughter ions (Id) on the detection of these toxaphene congeners was assessed in standard solution and biological samples. Our results indicate that different Ip and Id, selected at either low or high mass-to-charge (m/z) ratios, influence drastically the response factor of the CHBs and the chemical noise observed. For the octachlorinated toxaphene congeners (Parlar-26 (P-26), Parlar-40/41 (P-40/41), Parlar-44 (P-44)), the detection performance of the ion trap MS/MS is similar whether Ip and Id were chosen at low or high m/z ratios. However, the selection of Ip and Id at high m/z ratios clearly enhances the detection of the nonachlorinated toxaphene congeners (Parlar-50 (P-50), Parlar-62 (P-62)). The improved method, which selects Ip and Id at low m/z ratios for P-26, P-40/41 and P-44 and at high m/z ratios for P-50 and P-62, permitted to obtain low detection limits as well as repeatable and accurate results.

  14. Multimycotoxin UPLC-MS/MS for tea, herbal infusions and the derived drinkable products.

    PubMed

    Monbaliu, Sofie; Wu, Aibo; Zhang, Dabing; Van Peteghem, Carlos; De Saeger, Sarah

    2010-12-22

    In recent years the consumption of tea and herbal infusions has increased. These hot drinks are consumed as daily drinks as well as for medicinal purposes. All tea varieties (white, yellow, green, oolong, black and puerh) originate from the leaves of the tea plant, Camellia sinensis. All extracts made of plant or herbal materials which do not contain Camellia sinensis are referred as herbal infusions or tisanes. During processing and manufacturing fungal contamination of the plant materials is possible, enabling contamination of these products with mycotoxins. In this study a multimycotoxin UPLC-MS/MS method was developed and validated for the analysis of the raw tea and herbal infusion materials as well as for their drinkable products. The samples were analyzed by ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), with a mobile phase consisting of variable mixtures of water and methanol with 0.3% formic acid. The limits of detection for the different mycotoxins varied between 2.1 μg/kg and 121 μg/kg for raw materials and between 0.4 μg/L and 46 μg/L for drinkable products. Afterward 91 different tea and herbal infusion samples were analyzed. Only in one sample, Ceylon melange, 76 μg/kg fumonisin B(1) was detected. No mycotoxins were detected in the drinkable products.

  15. Method validation and analysis of nine dithiocarbamates in fruits and vegetables by LC-MS/MS.

    PubMed

    Schmidt, B; Christensen, H B; Petersen, A; Sloth, J J; Poulsen, M E

    2013-01-01

    An analytical method for separation and quantitative determination of nine dithiocarbamates (DTCs) in fruits and vegetables by using LC-MS/MS was developed, validated and applied to samples purchased in local supermarkets. The nine DTCs were ziram, ferbam, thiram, maneb, zineb, nabam, metiram, mancozeb and propineb. Validation parameters of mean recovery for two matrices at two concentration levels, relative repeatability (RSDr), relative within-laboratory reproducibility (RSDR) and LOD were obtained for the nine DTCs. The results from the analysis of fruits and vegetables served as the basis for an exposure assessment within the given commodities and a risk assessment by comparing the calculated exposure to the acceptable daily intake and acute reference dose for various exposure groups. The analysis indicated positive findings of DTCs in apples, pears, plums, table grapes, papaya and broccoli at concentrations ranging from 0.03 mg/kg to 2.69 mg/kg expressed as the equivalent amount of CS2. None of the values exceeded the Maximum residue level (MRL) set by the European Union, and furthermore, it was not possible to state whether illegal use had taken place or not, because a clear differentiation between the various DTCs in the LC-MS/MS analysis was lacking. The exposure and risk assessment showed that only for maneb in the case of apples and apple juice, the acute reference dose was exceeded for infants in the United Kingdom and for children in Germany, respectively.

  16. Rapid Analysis of Listeria monocytogenes Cell Wall Teichoic Acid Carbohydrates by ESI-MS/MS

    PubMed Central

    Eugster, Marcel R.; Loessner, Martin J.

    2011-01-01

    We report the application of electrospray ionization (ESI) mass spectrometry for compositional characterization of wall teichoic acids (WTA), a major component of Gram-positive bacterial cell walls. Tandem mass spectrometry (ESI-MS/MS) of purified and chemically hydrolyzed monomeric WTA components provided sufficient information to identify WTA monomers and their specific carbohydrate constituents. A lithium matrix was used for ionization of uncharged WTA monomers, and successfully applied to analyze the WTA molecules of four Listeria strains differing in carbohydrate substitution on a conserved polyribitol-phosphate backbone structure. Carbohydrate residues such as N-acetylglucosamine or rhamnose linked to the WTA could directly be identified by ESI-MS/MS, circumventing the need for quantitative analysis by gas chromatography. The presence of a terminal N-acetylglucosamine residue tethered to the ribitol was confirmed using fluorescently labeled wheat-germ agglutinin. In conclusion, the mass spectrometry method described here will greatly facilitate compositional analysis and characterization of teichoic acids and similar macromolecules from diverse bacterial species, and represents a significant advance in the identification of serovar-specific carbohydrates and sugar molecules on bacteria. PMID:21738682

  17. LC-MS/MS Validation Analysis of Trastuzumab Using dSIL Approach for Evaluating Pharmacokinetics.

    PubMed

    Budhraja, Rohit H; Shah, Milin A; Suthar, Mahendra; Yadav, Arun; Shah, Sahil P; Kale, Prashant; Asvadi, Parisa; Valan Arasu, Mariadhas; Al-Dhabi, Naif Abdullah; Park, Chun Geon; Kim, Young-Ock; Kim, Hak Jae; Agrawal, Y K; Krovidi, Ravi K

    2016-11-02

    Quantitative targeted proteomics based approaches deploy state-of-the-art Liquid chromatography tandem mass spectrometry LC-MS technologies and are evolving as a complementary technique to standard ligand-binding based assays. Advancements in MS technology, which have augmented the specificity, selectivity and sensitivity limits of detection and freedom from antibody generation, have made it amicable towards various clinical applications. In our current work, a surrogate peptide based quantitative proteomics assessment is performed by selecting specific signature peptides from the complementary determining region CDR region of trastuzumab (Herclon(®), Roche products in India). We developed a double Stable Isotope Label (dSIL) approach by using two different surrogate peptides to evaluate the proteolytic digestion efficiency and accurate quantification of the target analyte peptide of Herclon(®) in human serum. Method validation experiments were meticulously performed as per bioanalytical method validation guidelines. The dSIL approach, using an LC-MS/MS based quantification assay demonstrated good linearity over a range of 5-500 µg/mL of Herclon(®), and validation experimental data is in compliance with bioanalytical regulatory guidelines.

  18. [Simultaneous determination of gestodene, etonogestrel and ethinylestradiol in plasma by LC-MS/MS following derivatization].

    PubMed

    Liu, Xiao-Fen; Ding, Cun-Gang; Ge, Qing-Hua; Zhou, Zhen; Zhi, Xiao-Jin

    2010-01-01

    To establish a sensitive and specific method for simultaneous determination of gestodene, etonogestrel and ethinylestradiol in plasma by LC-MS/MS, plasma samples were extracted and derivatized before injection. An ESI ion source was used and operated in the positive ion mode with multiple reaction monitoring (MRM). Norgestrel was chosen as internal standard and performed on a C18 (100 mm x 2.1 mm, 5 microm) column. The concentrations of gestodene, etonogestrel and ethinylestradiol were measured, using step-gradient mobile phase and step-gradient flow rate. The method was validated over the concentration range of 0.1-20 ng x mL(-1) for gestodene and etonogestrel and 0.01-2 ng x mL(-1) for ethinylestradiol, and showed excellent linearity. The intra- and inter-assay accuracy and precision were below 10.0% and recovery was 93.6%-110.9% over the three concentration levels evaluated. The method was applied in pharmacokinetic study of the compound gestodene patch and the compound etonogestrel patch in rabbits. The LC-MS/MS method was selective, accurate and sensitive, especially the LOQ were 100 pg x mL(-1) for gestodene and etonogestrel and 10 pg x mL(-1) for ethinylestradiol. The method was successfully applied in pharmacokinetic study for contraceptives.

  19. Simultaneous determination of β-agonists and psychiatric drugs in feeds by LC-MS-MS.

    PubMed

    Suo, D C; Zhao, G L; Wang, P L; Su, X O

    2014-08-01

    A method was developed for the simultaneous determination of nine β-agonists (cimaterol, ractopamine, terbutaline, zilpaterol, salbutamol, clenbuterol, mabuterol, bambuterol and brombuterol) and six psychiatric drugs (diazepam, nitrazepam, oxazepam, chlorpromazine, promethazine and perphenazine) in animal feed by using solid-phase extraction (SPE) followed by liquid chromatography-tandem mass spectrometry (LC-MS-MS). Conditions were optimized for the extraction of the target analytes from animal feed and for clean-up with MCX SPE cartridges. The eluent was evaporated to dryness under nitrogen, and the residue was dissolved in a solution of acetonitrile and 1% formic acid (2:8, v/v) and analyzed by LC-MS-MS using an isotopic internal standard for quantification. Under the optimum conditions, the recovery values of the target analytes were between 70.1 and 110%, with coefficients of variation between 1.9 and 18.4%. The method was very reliable for the simultaneous determination of nine β-agonists and six psychiatric drugs in animal feed.

  20. Application of LC-MS/MS MRM to Determine Staphylococcal Enterotoxins (SEB and SEA) in Milk

    PubMed Central

    Andjelkovic, Mirjana; Tsilia, Varvara; Rajkovic, Andreja; De Cremer, Koen; Van Loco, Joris

    2016-01-01

    Staphylococcus aureus is one of the important aetiological agents of food intoxications in Europe and can cause gastro-enteritis through the production of various staphylococcal enterotoxins (SEs) in foods. Due to their stability and ease of production and dissemination, some SEs have also been studied as potential agents for bioterrorism. Therefore, specific and accurate analytical tools are required to detect and quantify SEs. Online solid-phase extraction liquid chromatography electrospray ionization tandem mass spectrometry (online SPE-LC-ESI-MS/MS) based on multiple reaction monitoring (MRM) was used to detect and quantify two types of SE (A and B) spiked in milk and buffer solution. SE extraction and concentration was performed according to the European Screening Method developed by the European Reference Laboratory for Coagulase Positive Staphylococci. Trypsin digests were screened for the presence of SEs using selected proteotypic heavy-labeled peptides as internal standards. SEA and SEB were successfully detected in milk samples using LC-MS/MS in MRM mode. The selected SE peptides were proteotypic for each toxin, allowing the discrimination of SEA and SEB in a single run. The detection limit of SEA and SEB was approximately 8 and 4 ng/g, respectively. PMID:27104569

  1. Simultaneous analysis of 35 specific antihypertensive adulterants in dietary supplements using LC/MS/MS.

    PubMed

    Heo, Seok; Choi, Ji Yeon; Yoo, Geum Joo; Park, Sung-Kwan; Baek, Sun Young

    2017-04-01

    A sensitive and specific LC/MS/MS method was developed for the simultaneous analysis of 35 compounds used for treating hypertension as adulterants in dietary supplements. The method was validated for specificity, linearity, accuracy, precision, limit of detection, limit of quantitation, stability and recovery. The limit of detection and limit of quantitation ranged from 0.20 to 20.0 and 0.50 to 60.0 ng/g, respectively. The linearity was good (r(2)  > 0.999), with intra- and interday precision levels of 0.43-7.87% and 0.65-9.95% and the intra- and interday accuracies of 84.36-115.82% and 83.78-118.69%, respectively. The stability (relative standard deviation) was <14.75%. The mean recovery was 80.81-117.86% (relative standard deviation <10.00%). Ninety-seven commercial dietary supplements available in South Korea were analyzed. While none contained detectable amounts of the 35 antihypertensive compounds, the developed LC/MS/MS procedure can be used for routine analysis to monitor illegal adulteration in various forms of dietary supplements. Copyright © 2016 John Wiley & Sons, Ltd.

  2. Novel LC/MS/MS and High-Throughput Mass Spectrometric Assays for Monoacylglycerol Acyltransferase Inhibitors.

    PubMed

    Qi, Jenson; Masucci, John A; Lang, Wensheng; Connelly, Margery A; Caldwell, Gary W; Petrounia, Ioanna; Kirkpatrick, Jennifer; Barnakov, Alexander N; Struble, Geoffrey; Miller, Robyn; Dzordzorine, Keli; Kuo, Gee-Hong; Gaul, Michael; Pocai, Alessandro; Lee, Seunghun

    2017-04-01

    Monoacylglycerol acyltransferase enzymes (MGAT1, MGAT2, and MGAT3) convert monoacylglycerol to diacylglycerol (DAG). MGAT1 and MGAT2 are both implicated in obesity-related metabolic diseases. Conventional MGAT enzyme assays use radioactive substrates, wherein the product of the MGAT-catalyzed reaction is usually resolved by time-consuming thin layer chromatography (TLC) analysis. Furthermore, microsomal membrane preparations typically contain endogenous diacylglycerol acyltransferase (DGAT) from the host cells, and these DGAT activities can further acylate DAG to form triglyceride (TG). Our mass spectrometry (liquid chromatography-tandem mass spectrometry, or LC/MS/MS) MGAT2 assay measures human recombinant MGAT2-catalyzed formation of didecanoyl-glycerol from 1-decanoyl-rac-glycerol and decanoyl-CoA, to produce predominantly 1,3-didecanoyl-glycerol. Unlike 1,2-DAG, 1,3-didecanoyl-glycerol is proved to be not susceptible to further acylation to TG. 1,3-Didecanoyl-glycerol product can be readily solubilized and directly subjected to high-throughput mass spectrometry (HTMS) without further extraction in a 384-well format. We also have established the LC/MS/MS MGAT activity assay in the intestinal microsomes from various species. Our assay is proved to be highly sensitive, and thus it allows measurement of endogenous MGAT activity in cell lysates and tissue preparations. The implementation of the HTMS MGAT activity assay has facilitated the robust screening and evaluation of MGAT inhibitors for the treatment of metabolic diseases.

  3. [LC-MS/MS analysis of determination of strychnine and brucine in formaldehyde fixed tissue].

    PubMed

    Zhan, Lan-fen; Liu, Ming-dong; Yan, You-yi; Ye, Yi; Wang, Wei; Wang, Zhi-hui; Zhao, Jun-hong; Liao, Lin-chuan

    2012-10-01

    To establish a method for determination of strychnine and brucine in formaldehyde fixed tissue by LC-MS/MS analysis. The samples were pretreated with solid phase extraction using SCX cartridges and separated on SB-C18 column with mobile phase 0.1% formic acid : 0.1% formic acid-acetonitrile (75:25). Electrospray ionization (ESI) source was utilized and operated in positive ion mode. Multiple reactions monitoring (MRM) mode was applied. External standard method was applied for quantitation. The chromatographic separation of strychnine and brucine in formaldehyde fixed nephritic and hepatic tissues resulted successfully. The standard curve was linear in the range of 0.002-2.0 microg/g for strychnine and brucine in formaldehyde fixed tissues, and the correlation coefficient was more than 0.996. The limits of detection (LOD) of strychnine and brucine in nephritic tissues were 0.06ng/g and 0.03 ng/g, respectively. The LOD of both chemicals were 0.3 ng/g in hepatic tissues. The extraction recovery rate was more than 74.5%. The precision of intra-day and inter-day were both less than 8.2%. Strychnine and brucine can be sensitive to be determined in formaldehyde fixed tissue by LC-MS/MS analysis. It can be applied in the forensic toxicological analysis.

  4. The determination of haloacetic acids in real world samples using IC-ESI-MS-MS.

    PubMed

    Slingsby, Rosanne; Saini, Charanjit; Pohl, Christopher

    2009-08-01

    This paper presents the determination of nine haloacetic acids (HAAs) in high ionic strength, treated effluent waters using an ion chromatography-electrospray ionization-tandem mass spectrometry (IC-ESI-MS-MS) method with internal standards and discussions of each of the method parameters. Data is also provided for these same samples using USEPA Method 552.2. The sample matrices contain up to 170 mg/L chloride and 243 mg/L sulfate. Matrix ions are separated from the analytes using a high capacity anion exchange analytical column and diverted to a waste stream during each analysis to avoid signal suppression and contamination of the detector. No derivatization, offline matrix elimination, or preconcentration is used. Four isotopically-labeled HAAs are used for quantification, and detection limits are in the range of 400-1000 microg/L with R(2) of at least 0.997 over two orders of magnitude for all analytes in matrix. A trichloroacetic acid (TCAA) internal standard with the label on the alpha carbon is found to be more stable than the TCAA-1-(13)C. Amounts found using IC-MS-MS are 65-130% of amounts found using Method 552.2 for all analytes in the real world treated effluent waters. Detection limits for all nine analytes in matrix are in the range of 100-700 ng/L.

  5. Photocatalytic degradation of hexazinone and its determination in water via UPLC-MS/MS.

    PubMed

    Mei, Mei; Du, Zhenxia; Xu, Ruifen; Chen, Yun; Zhang, Haojie; Qu, Shuping

    2012-06-30

    Degradation of hexazinone has been investigated by means of photocatalysis of mixed-phase crystal nano-TiO(2). Influences of adsorption, amount of nano-TiO(2), pH and irradiation time on the photocatalytic process are studied. Results show that hexazinone is totally degraded within 40min of irradiation under pH neutral conditions. This compares favorably with Degussa P25 TiO(2) when conducted under the same experimental conditions. Preliminary photocatalytic kinetic information for hexazinone degradation is proposed. First order kinetics is obtained for the adsorption and photocatalytic degradation reactions, which fit the Langmuir-Hinshelwood model. A rapid, sensitive and accurate UPLC-MS/MS technique is developed and utilized to determine the level of hexazinone in water in support of the degradation kinetics study. The results indicate a limit of detection (LOD) at 0.05μg/l and the recoveries between 90.2 and 98.5% with relative standard deviations (RSD) lower than 12%. A LC-MS/MS technique is used to trace the degradation process. Complete degradation is achieved into final products including nontoxic water, carbon dioxide and urea. A probable pathway for the total photocatalytic degradation of hexazinone is proposed.

  6. Detection of β-methylphenethylamine, a novel doping substance, by means of UPLC/MS/MS.

    PubMed

    Chołbiński, Piotr; Wicka, Mariola; Kowalczyk, Katarzyna; Jarek, Anna; Kaliszewski, Paweł; Pokrywka, Andrzej; Bulska, Ewa; Kwiatkowska, Dorota

    2014-06-01

    Novel substances of expected doping activity are constantly introduced to the market. β-Methylphenethylamine (BMPEA) is classified as a doping agent by the World Anti-Doping Agency as it is a positional isomer of amphetamine. In this work, the development and application of a simple and rapid analytical procedure that enables discrimination between both isomers is described. The analytes of interest were extracted from urine by a two-step liquid-liquid extraction and then analyzed by UPLC/MS/MS under isocratic conditions. The entire analytical procedure was validated by evaluating its selectivity, discrimination capabilities, carry-over, sensitivity, and influence of matrix effects on its performance. Application of the method resulted in detection of BMPEA in eight anti-doping samples, including the first report of adverse analytical finding regarding its use. Further analysis showed that BMPEA may be eliminated unchanged along with its phase II conjugates, the hydrolysis of which may considerably improve detection capabilities of the method. Omission of the hydrolysis step may therefore, produce false-negative results. Testing laboratories should also carefully examine their LC/MS/MS-based amphetamine and BMPEA findings as both isomers fragment yielding comparable collision-induced dissociation spectra and their insufficient chromatographic separation may result in misidentification. This is of great importance in case of forensic analyses as BMPEA is not controlled by the public law, and its manufacturing, distribution, and use are legal.

  7. Quantitation of amphetamine-type stimulants by LC-MS/MS.

    PubMed

    Middleberg, Robert A; Homan, Joseph

    2012-01-01

    Amphetamines or amphetamine-type stimulants (ATSs) refer to a group of pharmacological and -toxicological agents that have a common phenethylamine structural backbone and typically impart effects that include, but are not limited to, vasoconstriction, anorexia, central nervous system stimulation, and/or hallucinations. While differences in side chain chemistry can impart different pharmacological or toxicological effects, for some compounds, e.g., MDMA (Ecstasy), alterations of the phenyl part of the molecule impart other significant effects. ATSs are used both therapeutically and recreationally, with significant abuse and addiction potential. Therapeutically, these agents are mainly used to treat hyperactivity disorders or aid in weight loss. Toxicological effects include hypertension, arrhythmia, excitability, aggressiveness, psychoses, coma, and death.Traditional analytical methods to analyze amphetamines include gas chromatography-mass spectrometry where derivatization is often required to facilitate analysis. Besides sample preparation issues, it has been demonstrated that injection port chemistry in the GC can lead to misleading results with some members of the amphetamine class. To circumvent these issues, liquid chromatography-mass spectrometry (LC-MS/MS) offers the promise of a simpler sample preparation procedure and fewer analytical concerns. This chapter describes an LC-MS/MS technique for the analysis of 14 ATSs in blood, serum/plasma, and urine. The method is quantitative and has reporting limits in the low ng/mL range. Electrospray ionization is used in the positive ion mode. Two transitions for each compound are monitored along with ion ratios.

  8. LC-MS/MS Identification of a Bromelain Peptide Biomarker from Ananas comosus Merr.

    PubMed

    Secor, Eric R; Szczepanek, Steven M; Singh, Anurag; Guernsey, Linda; Natarajan, Prabitha; Rezaul, Karim; Han, David K; Thrall, Roger S; Silbart, Lawrence K

    2012-01-01

    Bromelain (Br) is a cysteine peptidase (GenBank AEH26024.1) from pineapple, with over 40 years of clinical use. The constituents mediating its anti-inflammatory activity are not thoroughly characterized and no peptide biomarker exists. Our objective is to characterize Br raw material and identify peptides in the plasma of Br treated mice. After SDS-PAGE in-gel digestion, Br (VN#3507; Middletown, CT, USA) peptides were analyzed via LC/MS/MS using 95% protein probability, 95% peptide probability, and a minimum peptide number = 5. Br spiked mouse plasma (1 ug/ul) and plasma from i.p. treated mice (12 mg/kg) were assessed using SRM. In Br raw material, we identified seven proteins: four proteases, one jacalin-like lectin, and two protease inhibitors. In Br spiked mouse plasma, six proteins (ananain, bromelain inhibitor, cysteine proteinase AN11, FB1035 precursor, FBSB precursor, and jacalin-like lectin) were identified. Using LC/MS/MS, we identified the unique peptide, DYGAVNEVK, derived from FB1035, in the plasma of i.p. Br treated mice. The spectral count of this peptide peaked at 6 hrs and was undetectable by 24 hrs. In this study, a novel Br peptide was identified in the plasma of treated mice for the first time. This Br peptide could serve as a biomarker to standardize the therapeutic dose and maximize clinical utility.

  9. Rapid analysis of Listeria monocytogenes cell wall teichoic acid carbohydrates by ESI-MS/MS.

    PubMed

    Eugster, Marcel R; Loessner, Martin J

    2011-01-01

    We report the application of electrospray ionization (ESI) mass spectrometry for compositional characterization of wall teichoic acids (WTA), a major component of gram-positive bacterial cell walls. Tandem mass spectrometry (ESI-MS/MS) of purified and chemically hydrolyzed monomeric WTA components provided sufficient information to identify WTA monomers and their specific carbohydrate constituents. A lithium matrix was used for ionization of uncharged WTA monomers, and successfully applied to analyze the WTA molecules of four Listeria strains differing in carbohydrate substitution on a conserved polyribitol-phosphate backbone structure. Carbohydrate residues such as N-acetylglucosamine or rhamnose linked to the WTA could directly be identified by ESI-MS/MS, circumventing the need for quantitative analysis by gas chromatography. The presence of a terminal N-acetylglucosamine residue tethered to the ribitol was confirmed using fluorescently labeled wheat-germ agglutinin. In conclusion, the mass spectrometry method described here will greatly facilitate compositional analysis and characterization of teichoic acids and similar macromolecules from diverse bacterial species, and represents a significant advance in the identification of serovar-specific carbohydrates and sugar molecules on bacteria.

  10. Annotation of Different Dehydrocatechin Oligomers by MS/MS and Their Occurrence in Black Tea.

    PubMed

    Verloop, Annewieke J W; Gruppen, Harry; Vincken, Jean-Paul

    2016-08-03

    Dehydrocatechins (DhC's), oligomeric oxidation products of (epi)catechins, were formed in model incubations of epicatechin with mushroom tyrosinase. DhC oligomers up to tetramers were detected by reversed-phase ultrahigh-performance liquid chromatography mass spectrometry (RP-UHPLC-MS) analysis. Measurements with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) showed formation of oligomers up to at least 15 catechin subunits. Isomeric DhC's were obtained, and a method based on MS(2) fragment ratios was set up to distinguish between the different interflavanic configurations of the isomers. In the model incubation, 8 dehydrodicatechins (DhC2's) and 22 dehydrotricatechins (DhC3's) were tentatively annotated by their MS(2) signature fragments. Three different interflavanic configuration types were determined for the DhC2's. DhC2's and DhC3's were shown to occur in a black tea extract for the first time. For the DhC2's, at least two isomeric types, i.e., DhC β and DhC ε, could be annotated in black tea.

  11. Detection and validated quantification of toxic alkaloids in human blood plasma--comparison of LC-APCI-MS with LC-ESI-MS/MS.

    PubMed

    Beyer, Jochen; Peters, Frank T; Kraemer, Thomas; Maurer, Hans H

    2007-05-01

    Poisonings with toxic plants may occur after abuse, intentional or accidental ingestion of plants. For diagnosis of such poisonings, multianalyte procedures were developed for detection and validated quantification of the toxic alkaloids aconitine, atropine, colchicine, coniine, cytisine, nicotine and its metabolite cotinine, physostigmine, and scopolamine in plasma using LC-APCI-MS and LC-ESI-MS/MS. After mixed-mode solid-phase extraction of 1 ml of plasma, the analytes were separated using a C8 base select separation column and gradient elution (acetonitrile/ammonium formate, pH 3.5). Calibration curves were used for quantification with cotinine-d(3), benzoylecgonine-d(3), and trimipramine-d(3) as internal standards. The method was validated according to international guidelines. Both assays were selective for the tested compounds. No instability was observed after repeated freezing and thawing or in processed samples. The assays were linear for coniine, cytisine, nicotine and its metabolite cotinine, from 50 to 1000 ng/ml using LC-APCI-MS and 1 to 1000 ng/ml using LC-ESI-MS/MS, respectively, and for aconitine, atropine, colchicine, physostigmine, and scopolamine from 5 to 100 ng/ml for LC-APCI-MS and 0.1 to 100 ng/ml for LC-ESI-MS/MS, respectively. Accuracy ranged from -38.6 to 14.0%, repeatability from 2.5 to 13.5%, and intermediate precision from 4.8 to 13.5% using LC-APCI-MS and from -38.3 to 8.3% for accuracy, from 3.5 to 13.8%, for repeatability, and from 4.3 to 14.7% for intermediate precision using LC-ESI-MS/MS. The lower limit of quantification was fixed at the lowest calibrator in the linearity experiments. With the exception of the greater sensitivity and higher identification power, LC-ESI-MS/MS had no major advantages over LC-APCI-MS. Both presented assays were applicable for sensitive detection of all studied analytes and for accurate and precise quantification, with the exception of the rather volatile nicotine. The applicability of the assays was

  12. Applications of LC/ESI-MS/MS and UHPLC QqTOF MS for the determination of 148 pesticides in fruits and vegetables.

    PubMed

    Wang, Jian; Chow, Willis; Leung, Daniel

    2010-02-01

    This paper presented the applications of liquid chromatography electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) and ultra-high-pressure liquid chromatography electrospray ionization quadrupole time-of-flight mass spectrometry (UHPLC QqTOF MS) for the determination of 148 pesticides in fruits and vegetables. Pesticides were extracted from fruits and vegetables using a buffered QuEChERS method. Quantification was achieved using matrix-matched standard calibration curves with isotopically labeled standards or a chemical analog as internal standards in an analytical range from 5 to 500 microg/kg. The method performance parameters including overall recovery, intermediate precision, and measurement uncertainty were evaluated according to a statistically designed experiment, i.e., a nested design. For LC/ESI-MS/MS, 95% of the pesticides had recoveries between 81% and 110%; 97% had an intermediate precision < or = 20%; and 95% (in fruits) or 93% (in vegetables) showed measurement uncertainty < or = 40%. Compared to LC/ESI-MS/MS, UHPLC QqTOF MS showed a relatively poor repeatability and large measurement uncertainty. About 93% (in fruits) or 94% (in vegetables) of the pesticides had recoveries between 81% and 110%; 86% (in fruits) or 90% (in vegetables) had an intermediate precision < or = 20%; and 79% (in fruits) or 88% (in vegetables) showed measurement uncertainty < or = 40%. LC/ESI-MS/MS proved to be the first choice for quantification or pre-target analysis due to its superior sensitivity and good repeatability. UHPLC QqTOF MS provided accurate mass measurement and isotopic patterns, and was an ideal tool for post-target screening and confirmation.

  13. Identified EM Earthquake Precursors

    NASA Astrophysics Data System (ADS)

    Jones, Kenneth, II; Saxton, Patrick

    2014-05-01

    Many attempts have been made to determine a sound forecasting method regarding earthquakes and warn the public in turn. Presently, the animal kingdom leads the precursor list alluding to a transmission related source. By applying the animal-based model to an electromagnetic (EM) wave model, various hypotheses were formed, but the most interesting one required the use of a magnetometer with a differing design and geometry. To date, numerous, high-end magnetometers have been in use in close proximity to fault zones for potential earthquake forecasting; however, something is still amiss. The problem still resides with what exactly is forecastable and the investigating direction of EM. After a number of custom rock experiments, two hypotheses were formed which could answer the EM wave model. The first hypothesis concerned a sufficient and continuous electron movement either by surface or penetrative flow, and the second regarded a novel approach to radio transmission. Electron flow along fracture surfaces was determined to be inadequate in creating strong EM fields, because rock has a very high electrical resistance making it a high quality insulator. Penetrative flow could not be corroborated as well, because it was discovered that rock was absorbing and confining electrons to a very thin skin depth. Radio wave transmission and detection worked with every single test administered. This hypothesis was reviewed for propagating, long-wave generation with sufficient amplitude, and the capability of penetrating solid rock. Additionally, fracture spaces, either air or ion-filled, can facilitate this concept from great depths and allow for surficial detection. A few propagating precursor signals have been detected in the field occurring with associated phases using custom-built loop antennae. Field testing was conducted in Southern California from 2006-2011, and outside the NE Texas town of Timpson in February, 2013. The antennae have mobility and observations were noted for

  14. Proteomic analysis of infiltrating ductal carcinoma tissues by coupled 2-D DIGE/MS/MS analysis.

    PubMed

    Davalieva, K; Kiprijanovska, S; Broussard, C; Petrusevska, G; Efremov, G D

    2012-01-01

    There is a growing interest in protein expression profiling aiming to identify novel diagnostic markers in breast cancer. Proteomic approaches such as two-dimensional differential gel electrophoresis coupled with tandem mass spectrometry analysis (2-D DIGE/MS/MS) have been used successfully for the identification of candidate biomarkers for screening, diagnosis, prognosis and monitoring of treatment response in various types of cancer. Identifying previously unknown proteins of potential clinical relevance will ultimately help in reaching effective ways to manage the disease. We analyzed breast cancer tissues from five tumor and five normal tissue samples from ten breast cancer subjects with infiltrating ductal carcinoma (IDC) by 2-D DIGE using two types of immobilized pH gradient (IPG) strips: pH 3-10 and pH 4-7. From all the spots detected, differentially expressed (p < 0.05 and ratio > 2) were 50 spots. Of these, 39 proteins were successfully identified by MS, representing 29 different proteins. Ten proteins were overexpressed in the tumor samples. The 2-D DIGE/MS/MS analysis revealed an increase in the expression levels in tumor samples of several proteins not previously associated with breast cancer, such as: macrophage-capping protein (CAPG), phosphomannomutase 2 (PMM2), ATPase ASN1, methylthioribose-1-phosphate isomerase (MRI1), peptidyl-prolyl cis-trans isomerase FKBP4, cellular retinoic acid-binding protein 2 (CRABP2), lamin B1 and keratin, type II cytoskeletal 8 (KRT8). Ingenuity Pathway Analysis (IPA) revealed highly significant (p = 10(-26)) interactions between the identified proteins and their association with cancer. These proteins are involved in many diverse pathways and have established roles in cellular metabolism. It remains the goal of future work to test the suitability of the identified proteins in samples of larger and independent patient groups.

  15. Sensitive determination of oxybutynin and desethyloxybutynin in dog plasma by LC-ESI/MS/MS.

    PubMed

    Kim, Hohyun; Han, Sang Beom

    2003-02-26

    A sensitive and selective liquid chromatographic method coupled with tandem mass spectrometry (LC-MS/MS) was developed for the quantification of oxybutynin and desethyloxybutynin in dog plasma. Diazepam was used as internal standard, with plasma sample extracted using n-hexane and back-extracted using hydrochloric acid. A centrifuged lower layer (aqueous layer) was injected into a C(18) XTerra MS column (2.1 x 30 mm(2)) with 3.5 microm particle size. The analytical column lasted for at least 500 injections. The mobile phase was composed of 90% methanol, with flow rate at 200 microl/min. The mass spectrometer was operated in positive ion mode using electrospray ionization. Nitrogen was used as the nebulizer gas and argon was used as the collision gas. Using MS/MS with multiple reaction monitoring (MRM) mode, oxybutynin and desethyloxybutynin were detected without severe interferences from plasma matrix. Oxybutynin produced a protonated precursor ion ([M+H](+)) at m/z 358 and a corresponding product ion at m/z 142. Desethyloxybutynin produced a protonated precursor ion ([M+H](+)) at m/z 330 and a corresponding product ion at m/z 96. And internal standard (diazepam) produced a protonated precursor ion ([M+H](+)) at m/z 285 and a corresponding product ion at m/z 193. Detection of oxybutynin and desethyloxybutynin in dog plasma were accurate and precise, with detection limit at 0.1 ng/ml. This method has been successfully applied to a study of oxybutynin and desethyloxybutynin in dog plasma.

  16. Outdoor and indoor benzene evaluation by GC-FID and GC-MS/MS.

    PubMed

    Sousa, José A; Domingues, Valentina F; Rosas, Mónica S; Ribeiro, Susana O; Alvim-Ferraz, Conceiçao M; Delerue-Matos, Cristina F

    2011-01-01

    The evaluation of benzene in different environments such as indoor (with and without tobacco smoke), a city area, countryside, gas stations and near exhaust pipes from cars running on different types of fuels was performed. The samples were analyzed using gas chromatography (GC) with flame ionization detection (FID) and tandem mass spectrometric detection (MS/MS) (to confirm the identification of benzene in the air samples). Operating conditions for the GC-MS analysis were optimized as well as the sampling and sample preparation. The results obtained in this work indicate that i) the type of fuel directly influences the benzene concentration in the air. Gasoline with additives provided the highest amount of benzene followed by unleaded gasoline and diesel; ii) the benzene concentration in the gas station was always higher than the advisable limit established by law (5 μg m⁻³) and during the unloading of gasoline the achieved concentration was 8371 μg m⁻³; iii) the data from the countryside (Taliscas) and the urban city (Matosinhos) were below 5 μg m⁻³ except 5 days after a fire on a petroleum refinery plant located near the city; iv) it was proven that in coffee shops where smoking is allowed the benzene concentration is higher (6 μg m⁻³) than in coffee shops where this is forbidden (4 μg m⁻³). This method may also be helpful for environmental analytical chemists who use GC-MS/MS for the confirmation or/and quantification of benzene.

  17. Aqueous Organometal Speciation by GC-ICP-MS and HPLC-ICP-MS

    NASA Astrophysics Data System (ADS)

    Hannigan, R.

    2005-12-01

    Organometals, specifically organomercury, organotin and organolead, may only account for a small fraction of the total metal load in aquatic systems. Despite their lower relative abundance, organometal species may have a larger impact on the environment. Although biogeochemical studies of mercury, tin, and to a lesser degree lead, have been done, little is known about the transport and transformation of these organometals in the water column and, more specifically, at the sediment-water interface. Our knowledge is limited, in part, by the lack of instrumental techniques that provide simultaneous highly precise data about the metal species and binding ligand. We have developed a series of hyphenated techniques that allow for precise quantification of the elemental and organic forms of these metals. Most importantly these methods remove sample pre-treatment from the methods though headspace trap desorption, split injection and sequential chromatography with split detection providing detailed information about the metals and organics in stream water samples. Our data show that using headspace trap GC-ICP-MS it is possible to by-pass chromatographic separation of the species and detect elemental, dimethyl and methyl mercury in a single sample from a single injection. Additional research shows that GC-ICP-MS and HPLC-ICP-MS speciation of organotins provide differential speciation data with GC-ICP-MS detecting, at very low concentrations, butylins and HPLC-ICP-MS detecting, at very low concentrations, ethyltins. Integration of these techniques into a single system will eventually lead to a system which provides simultaneous detection of metals and organic binding ligands in a single sample.

  18. Segmental analysis of amphetamines in hair using a sensitive UHPLC-MS/MS method.

    PubMed

    Jakobsson, Gerd; Kronstrand, Robert

    2014-06-01

    A sensitive and robust ultra high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed and validated for quantification of amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine and 3,4-methylenedioxy methamphetamine in hair samples. Segmented hair (10 mg) was incubated in 2M sodium hydroxide (80°C, 10 min) before liquid-liquid extraction with isooctane followed by centrifugation and evaporation of the organic phase to dryness. The residue was reconstituted in methanol:formate buffer pH 3 (20:80). The total run time was 4 min and after optimization of UHPLC-MS/MS-parameters validation included selectivity, matrix effects, recovery, process efficiency, calibration model and range, lower limit of quantification, precision and bias. The calibration curve ranged from 0.02 to 12.5 ng/mg, and the recovery was between 62 and 83%. During validation the bias was less than ±7% and the imprecision was less than 5% for all analytes. In routine analysis, fortified control samples demonstrated an imprecision <13% and control samples made from authentic hair demonstrated an imprecision <26%. The method was applied to samples from a controlled study of amphetamine intake as well as forensic hair samples previously analyzed with an ultra high performance liquid chromatography time of flight mass spectrometry (UHPLC-TOF-MS) screening method. The proposed method was suitable for quantification of these drugs in forensic cases including violent crimes, autopsy cases, drug testing and re-granting of driving licences. This study also demonstrated that if hair samples are divided into several short segments, the time point for intake of a small dose of amphetamine can be estimated, which might be useful when drug facilitated crimes are investigated.

  19. Characterization of wine with PTR-MS

    NASA Astrophysics Data System (ADS)

    Boscaini, Elena; Mikoviny, Tomas; Wisthaler, Armin; Hartungen, Eugen Von; Märk, Tilmann D.

    2004-12-01

    A new method for measuring volatile profiles of alcoholic beverages (or other ethanol-containing analytes such as perfumes or herbs) has been developed. The method is based on proton transfer reaction mass spectrometry (PTR-MS). However, instead of hydronium ions (H3O+) protonated ethanol clusters (C2H5OH2+(C2H5OH)n = 1,2) are used as chemical ionization reagent ions. A stable reagent ion distribution is obtained by a 10-fold dilution of analyte headspace into ethanol-saturated nitrogen. Samples with different ethanol content can thus be directly compared. Characteristic mass spectral fingerprints have been obtained for four wine varieties. Principal component analysis discriminates between different wine varieties and shows specific correlations between wine variety and selected ions.

  20. ICP-MS Data Analysis Software

    SciTech Connect

    Kinard, W. Frank

    1999-01-14

    VG2Xl - this program reads binary data files generated by VG instrumentals inductively coupled plasma-mass spectrometers using PlasmaQuad Software Version 4.2.1 and 4.2.2 running under IBM OS/2. ICPCalc - this module is a macro for Microsoft Excel written in VBA (Virtual Basic for Applications) that performs data analysis for ICP-MS data required for nuclear materials that cannot readily be done with the vendor''s software. VG2GRAMS - This program reads binary data files generated by VG instruments inductively coupled plasma mass spectrometers using PlasmaQuad software versions 4.2.1 and 4.2.2 running under IBM OS/2.

  1. ICPCALC. ICP-MS Data Analysis Software

    SciTech Connect

    Kinard, F.

    1997-08-08

    VG2Xl - this program reads binary data files generated by VG instrumentals inductively coupled plasma-mass spectrometers using PlasmaQuad Software Version 4.2.1 and 4.2.2 running under IBM OS/2. ICPCalc - this module is a macro for Microsoft Excel written in VBA (Virtual Basic for Applications) that performs data analysis for ICP-MS data required for nuclear materials that cannot readily be done with the vendor`s software. VG2GRAMS - This program reads binary data files generated by VG instruments inductively coupled plasma mass spectrometers using PlasmaQuad software versions 4.2.1 and 4.2.2 running under IBM OS/2.

  2. Computer-aided tracking of MS lesions

    NASA Astrophysics Data System (ADS)

    Sturm, Deborah; Gurwitz Kletenik, Devorah; Koshy, Philip

    2011-03-01

    Multiple Sclerosis (MS) lesions are known to change over time. The location, size and shape characteristics of lesions are often used to diagnose and to track disease progression. We have improved our lesion-browsing tool that allows users to automatically locate successive significant lesions in a MRI stack. In addition, an automatic alignment feature was implemented to facilitate comparisons across stacks. A lesion stack is formed that can be browsed independently or in tandem with the image windows. Lesions of interest can then be measured, rendered and rotated. Multiple windows allow the viewer to compare the size and shape of lesions from the MRI images of the same patient taken at different time intervals.

  3. Semi-automated tandem mass spectrometric (MS/MS) triple quadrupole operating parameter optimization for high-throughput MS/MS detection workflows.

    PubMed

    Geddes, Kristin; Adamson, Gary; Dube, Neal; Crathern, Susan; King, Richard C

    2009-05-01

    This paper describes an automated workflow for the determination of selected reaction monitoring (SRM) transitions and optimum mass spectrometric (MS) instrument parameters. The approach uses a Nanomate from Advion Biosciences for automated infusion of small amounts of sample in combination with Automaton optimization software from Sciex. The results are stored in the Analyst software Compound Database for automated acquisition method building. Comparisons are presented between the more traditional optimization methods of manual flow injection optimization, Autotune infusion optimization, Automaton flow injection optimization and the Nanomate-Automaton optimization approach. Data is also presented to show that acquisition methods developed on the Sciex model API3000 instrument can be effectively transferred to the Sceix API4000 and API5000 model instruments. Copyright (c) 2009 John Wiley & Sons, Ltd.

  4. Direct sampling MS for environmental screening

    SciTech Connect

    Wise, M.B.; Guerin, M.R.

    1997-01-01

    Decades of improper storage and disposal of hazardous materials by government and industry have resulted in =40,000 contaminated sites that will require cleanup by state and federal agencies. Almost 1,300 of these sites are classified as especially serious threats and are listed on the Superfund National Priorities List (NPL) for accelerated remediation; by 2020, it is estimated that the number of NPL sites will exceed 3,000. Given that an average of 10 years is required to clean up a superfund site, remediation of known hazardous sites will continue well into the next century. Cost projections for environmental restoration range from nearly $200 billion to more than $2 trillion. DSMS is a simple technique that provides real-time response, high sample throughput, and ppb detection limits at low cost. This paper discusses screening methods and direct sampling MS (DSMS) for more cost-effective and efficient environmental characterization. 18 refs., 2 figs., 1 tab.

  5. Yield of 6,000 proteins by 1D nLC-MS/MS without pre-fractionation.

    PubMed

    Anagnostopoulos, Athanasios K; Stravopodis, Dimitrios J; Tsangaris, George Th

    2017-03-15

    Mass spectrometry (MS) has dominated over other protein analysis methods that aspire to deliver rapid and sensitive protein annotation, due to its ability to acquire high-content biological information from samples of great complexity. Routinely, in-depth analysis of complex biological samples, such as total cell lysates, relies on the high separation power of two-dimensional liquid chromatography-tandem MS (2D LC-MS/MS), often combined with protein pre-fractionation. However, on the basis of recent advances in chromatographic and MS instrumentation, one-dimensional (1D) LC-MS/MS approaches have become the method-of-choice for high-volume/high-throughput protein experiments. Thousands of proteins can be identified in single-run LC-MS/MS experiments. In the present study a 1D LC-MS/MS approach was applied on whole-cell lysates of WM-266-4 human cells leading to identification of more than 5,300 protein groups, 6,000 proteins and 22,00 peptides, in a single run. Using no pre-fractionation steps, method optimization was achieved through experimentation on lysis and protein extraction solutions, as well as nLC gradient parameters.

  6. Application of GC/Time-of-Flight-MS for halocarbon trace gas analysis and comparison with GC/Quadrupole-MS

    NASA Astrophysics Data System (ADS)

    Hoker, J.; Obersteiner, F.; Bönisch, H.; Engel, A.

    2014-12-01

    We present the application of Time-of-Flight Mass Spectrometry (TOF MS) for the analysis of halocarbons in the atmosphere, after cryogenic sample preconcentration and gas chromatographic separation. For the described field of application, the Quadrupole Mass Spectrometer (QP MS) is the state-of-the-art detector. This work aims at comparing two commercially available instruments, a QP MS and a TOF MS with respect to mass resolution, mass accuracy, sensitivity, measurement precision and detector linearity. Both mass spectrometers are operated on the same gas chromatographic system by splitting the column effluent to both detectors. The QP MS had to be operated in optimised Single Ion Monitoring (SIM) mode to achieve a sensitivity which could compete with the TOF MS. The TOF MS provided full mass range information in any acquired mass spectrum without losing sensitivity. Whilst the QP MS showed the performance already achieved in earlier tests, the sensitivity of the TOF MS was on average higher than that of the QP MS in the "operational" SIM mode by a factor of up to 3 reaching detection limits of less than 0.2 pg. Measurement precision determined for the whole analytical system was up to 0.2% depending on substance and sampled volume. The TOF MS instrument used for this study displayed significant non-linearities of up to 10% for two third of all analysed substances.

  7. Comparison of GC/time-of-flight MS with GC/quadrupole MS for halocarbon trace gas analysis

    NASA Astrophysics Data System (ADS)

    Hoker, J.; Obersteiner, F.; Bonisch, H.; Engel, A.

    2015-05-01

    We present the application of time-of-flight mass spectrometry (TOF MS) for the analysis of halocarbons in the atmosphere after cryogenic sample preconcentration and gas chromatographic separation. For the described field of application, the quadrupole mass spectrometer (QP MS) is a state-of-the-art detector. This work aims at comparing two commercially available instruments, a QP MS and a TOF MS, with respect to mass resolution, mass accuracy, stability of the mass axis and instrument sensitivity, detector sensitivity, measurement precision and detector linearity. Both mass spectrometers are operated on the same gas chromatographic system by splitting the column effluent to both detectors. The QP MS had to be operated in optimised single ion monitoring (SIM) mode to achieve a sensitivity which could compete with the TOF MS. The TOF MS provided full mass range information in any acquired mass spectrum without losing sensitivity. Whilst the QP MS showed the performance already achieved in earlier tests, the sensitivity of the TOF MS was on average higher than that of the QP MS in the "operational" SIM mode by a factor of up to 3, reaching detection limits of less than 0.2 pg. Measurement precision determined for the whole analytical system was up to 0.2% depending on substance and sampled volume. The TOF MS instrument used for this study displayed significant non-linearities of up to 10% for two-thirds of all analysed substances.

  8. Quantitation of Melatonin and N-acetylserotonin in Human Plasma by Nanoflow LC-MS/MS and Electrospray LC-MS/MS

    PubMed Central

    Carter, Melissa D.; Calcutt, M. Wade; Malow, Beth A.; Rose, Kristie L.; Hachey, David L.

    2012-01-01

    Melatonin (MEL) and its chemical precursor N-acetylserotonin (NAS) are believed to be potential biomarkers for sleep-related disorders. Measurement of these compounds, however, has proven to be difficult due to their low circulating levels, especially that of NAS. Few methods offer the sensitivity, specificity and dynamic range needed to monitor MEL and its precursors and metabolites in small blood samples, such as those obtained from pediatric patients. In support of our ongoing study to determine the safety, tolerability, and PK dosing strategies for MEL in treating insomnia in children with autism spectrum disorder, two highly sensitive LC-MS/MS assays were developed for the quantitation of MEL and precursor NAS at pg/mL levels in small volumes of human plasma. A validated electrospray ionization (ESI) method was used to quantitate high levels of MEL in PK studies and a validated nanospray (nESI) method was developed for quantitation of MEL and NAS at endogenous levels. In both assays plasma samples were processed by centrifugal membrane dialysis after addition of stable isotopic internal standards, and the components were separated by either conventional LC using a Waters SymmetryShield RP18 column (2.1×100 mm, 3.5 μm) or on a polyimide-coated, fused-silica capillary self-packed with 17 cm AquaC18 (3 μm, 125 Å). Quantitation was done using the SRM transitions m/z 233→174 and m/z 219→160 for MEL and NAS, respectively. The analytical response ratio vs. concentration curves were linear for MEL (nanoflow LC: 11.7–1165 pg/mL, LC: 1165–116500 pg/mL) and for NAS (nanoflow LC: 11.0–1095 pg/mL). PMID:22431453

  9. Segmental hair analysis for differentiation of tilidine intake from external contamination using LC-ESI-MS/MS and MALDI-MS/MS imaging.

    PubMed

    Poetzsch, Michael; Baumgartner, Markus R; Steuer, Andrea E; Kraemer, Thomas

    2015-02-01

    Segmental hair analysis has been used for monitoring changes of consumption habit of drugs. Contamination from the environment or sweat might cause interpretative problems. For this reason, hair analysis results were compared in hair samples taken 24 h and 30 days after a single tilidine dose. The 24-h hair samples already showed high concentrations of tilidine and nortilidine. Analysis of wash water from sample preparation confirmed external contamination by sweat as reason. The 30-day hair samples were still positive for tilidine in all segments. Negative wash-water analysis proved incorporation from sweat into the hair matrix. Interpretation of a forensic case was requested where two children had been administered tilidine by their nanny and tilidine/nortilidine had been detected in all hair segments, possibly indicating multiple applications. Taking into consideration the results of the present study and of MALDI-MS imaging, a single application as cause for analytical results could no longer be excluded. Interpretation of consumption behaviour of tilidine based on segmental hair analysis has to be done with caution, even after typical wash procedures during sample preparation. External sweat contamination followed by incorporation into the hair matrix can mimic chronic intake. For assessment of external contamination, hair samples should not only be collected several weeks but also one to a few days after intake. MALDI-MS imaging of single hair can be a complementary tool for interpretation. Limitations for interpretation of segmental hair analysis shown here might also be applicable to drugs with comparable physicochemical and pharmacokinetic properties.

  10. Aflatoxins contamination in Pakistani brown rice: a comparison of TLC, HPLC, LC-MS/MS and ELISA techniques.

    PubMed

    Iqbal, Javed; Asghar, Muhammad Asif; Ahmed, Aftab; Khan, Mobeen Ahmed; Jamil, Khalid

    2014-12-01

    Advancement in the field of analytical food-chemistry has explored various experimental techniques for aflatoxins (AFs) quantification. The present study was aimed to compare four different techniques; thin-layer chromatography (TLC), high-performance liquid chromatography (HPLC), liquid chromatography-tandem mass spectrometry (LC-MS/MS) and enzyme-linked immunosorbent assay (ELISA) for the analysis of aflatoxin B₁ (AFB₁), B₂ (AFB₂), G₁ (AFG₁) and G₂ (AFG₂) in brown rice (n = 120) being collected from Karachi, Pakistan. All the four assays provide precised, accurate and comparable results. However, some differences were observed. For instance, TLC, HPLC and LC-MS/MS methodologies offered the advantage of the quantification of individual toxins in contrast to ELISA technique. The contamination ranges of AFB₁/AFB₂ as determined by TLC, HPLC and LC-MS/MS were 1.18-9.97/0.59-1.52, 0.16-10.54/0.26-1.35 and 0.11-10.88/0.38-1.48 µg/kg, respectively. However, AFG₁ and AFG₂ were not detected in any tested samples. Furthermore, owing to low-detection limit and sensitivity, HPLC and LC-MS/MS methodologies have identified greater number of contaminated samples in comparison to TLC and ELISA techniques. The overall average results of total AFs as provided by HPLC (3.79 µg/kg) and LC-MS/MS (3.89 µg/kg) were found higher in comparison to TLC (3.68 µg/kg) and ELISA (3.70 µg/kg). On the basis of achieved results, it was concluded that TLC, HPLC, LC-MS/MS and ELISA techniques are valuable tool for the quantification of AFs in cereals and grains. Furthermore, HPLC and LC-MS/MS techniques offer an added advantage for the detection of AFs in diminutive levels.

  11. Title: The validation of Cryogenic Laser Ablation ICP-MS (CLA-ICP-MS) methods by comparison to laser ablation (LA)-ICP-MS and solution based ICP-MS methods, for the analysis of metals in biological tissues

    NASA Astrophysics Data System (ADS)

    Hannigan, R.; Darrah, T. H.; Horton, M.

    2009-12-01

    ICP-MS and laser ablation ICP-MS (LA-ICP-MS) are well established techniques for the analysis of metals in geological and environmental samples. LA-ICP-MS is commonly used in geological applications to determine the spatial distribution of metal concentrations at small sampling intervals (as low as 10 microns). However, measurement of metals in water-rich, soft biological tissues typically requires samples to be digested into solutions, obfuscating spatial variations in metal concentrations. The cryogenic cell solidifies (by freezing) soft tissue, allowing these tissues to be analyzed by laser ablation for spatial variations in metal concentration. The cell is temperature programmable and capable of maintaining a sample at any temperature between -35C and 25C throughout prolonged analysis. We validate the cryogenic laser ablation ICP-MS (CLA-ICP-MS) method using NIST Glass SRM 612. We also compare metal concentration data analyzed by cryogenic laser ablation ICP-MS (CLA-ICP-MS), LA-ICP-MS, and solution based ICP-MS, for human and rodent brain samples. The cryogenic laser ablation cell will expand analytical capabilities for measuring spatial distribution and concentration of metals incorporated into biological tissues.

  12. Multisteroid LC–MS/MS assay for glucocorticoids and androgens and its application in Addison's disease

    PubMed Central

    Methlie, Paal; Hustad, Steinar; Kellman, Ralf; Almås, Bjørg; Erichsen, Martina M; Husebye, Eystein S; Løvås, Kristian

    2013-01-01

    Objective Liquid chromatography–tandem mass spectrometry (LC–MS/MS) offers superior analytical specificity compared with immunoassays, but it is not available in many regions and hospitals due to expensive instrumentation and tedious sample preparation. Thus, we developed an automated, high-throughput LC–MS/MS assay for simultaneous quantification of ten endogenous and synthetic steroids targeting diseases of the hypothalamic–pituitary–adrenal axis and gonads. Methods Deuterated internal standards were added to 85 μl serum and processed by liquid–liquid extraction. Cortisol, cortisone, prednisolone, prednisone, 11-deoxycortisol, dexamethasone, testosterone, androstenedione and progesterone were resolved by ultra-high-pressure chromatography on a reversed-phase column in 6.1 min and detected by triple-quadrupole mass spectrometry. The method was used to assess steroid profiles in women with Addison's disease (AD, n=156) and blood donors (BDs, n=102). Results Precisions ranged from 4.5 to 10.1% relative standard deviations (RSD), accuracies from 95 to 108% and extraction recoveries from 60 to 84%. The method was practically free of matrix effects and robust to individual differences in serum composition. Most postmenopausal AD women had extremely low androstenedione concentrations, below 0.14 nmol/l, and median testosterone concentrations of 0.15 nmol/l (interquartile range 0.00–0.41), considerably lower than those of postmenopausal BDs (1.28 nmol/l (0.96–1.64) and 0.65 nmol/l (0.56–1.10) respectively). AD women in fertile years had androstenedione concentrations of 1.18 nmol/l (0.71–1.76) and testosterone concentrations of 0.44 nmol/l (0.22–0.63), approximately half of those found in BDs of corresponding age. Conclusion This LC–MS/MS assay provides highly sensitive and specific assessments of glucocorticoids and androgens with low sample volumes and is suitable for endocrine laboratories and research. Its utility has been

  13. Substitution pattern elucidation of hydroxypropyl Pinus pinaster (Ait.) bark polyflavonoid derivatives by ESI(-)-MS/MS.

    PubMed

    García Marrero, Danny E; Glasser, Wolfgang G; Pizzi, Antonio; Paczkowski, Sebastian; Laborie, Marie-Pierre G

    2014-10-01

    The structure of condensed tannins (CTs) from Pinus pinaster bark extract and their hydroxypropylated derivatives with four degrees of substitution (DS 1, 2, 3 and 4) has been characterized for the first time using negative-ion mode electrospray ionization tandem mass spectrometry (ESI(-)-MS/MS). The results showed that P. pinaster bark CTs possess structural homogeneity in terms of monomeric units (C(15), catechin). The oligomer sizes were detected to be dimers to heptamers. The derivatives showed typical phenyl-propyl ether mass fragmentation by substituent elimination (58 amu) and inherent C(15) flavonoid fissions. The relative abundance of the product ions revealed a preferential triple, tetra-/penta- and octa- hydroxypropylation substitution pattern in the monomer, dimer and trimer derivatives, respectively. A defined order of -OH reactivity towards propylene oxide was established by means of multistage experiments (A-ring ≥ B-ring > C-ring). A high structural heterogeneity of the modified oligomers was detected.

  14. Identification and Chemical Standardization of Licorice Raw Materials and Dietary Supplements Using UHPLC-MS/MS.

    PubMed

    Li, Guannan; Nikolic, Dejan; van Breemen, Richard B

    2016-10-04

    Defined as the roots and underground stems of principally three Glycyrrhiza species, G. glabra L., G.uralensis Fish. ex DC. and G. inflata Batalin, licorice has been used as a medicinal herb for millennia and is marketed as root sticks, powders and extracts. Identity tests described in most pharmacopeial monographs enabled the distinction of Glycyrrhiza species. Accordingly, an ultrahigh-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) assay using the method of standard addition was developed to quantify 14 licorice components (liquiritin, isoliquiritin, liquiritin apioside, isoliquiritin apioside, licuraside, liquiritigenin, isoliquiritigenin, glycyrrhizin, glycyrrhetinic acid, glabridin, glycycoumarin, licoricidin, licochalcone A, and p-hydroxybenzylmalonic acid), representing several natural product classes including chalcones, flavanones, saponins, and isoflavonoids. Using this approach, G. glabra, G. uralensis and G. inflata in a variety of forms including root powders and extracts as well as complex dietary supplements could be differentiated and chemically standardized without concerns due to matrix effects.

  15. [Analysis of tetracyclines in honey and royal jelly by LC/MS/MS].

    PubMed

    Ishii, Rie; Horie, Masakazu; Murayama, Mitsunori; Maitani, Tamio

    2006-12-01

    A simple and accurate method using liquid chromatography coupled with tandem mass spectrometry (LC/MS/MS) was developed for the determination of tetracyclines (TCs), i.e., oxytetracycline (OTC), chlortetracycline (CTC) and tetracycline (TC), in honey and royal jelly. Mass spectral acquisition was performed in the positive mode. In LC separation, L-column ODS and 0.01% formic acid-acetonitrile were used as the column and mobile phase, respectively. TCs in a honey sample were diluted with water, while TCs in royal jelly were extracted with 2% metaphosphoric acid-methanol (6:4). They were cleaned up with Oasis HLB and Sep Pak C18 cartridges, respectively. The quantification limits of TC, OTC, and CTC were 5, 5, and 10 ng/g, respectively, while those in royal jelly were 25, 25, and 50 ng/g, respectively. The recoveries of TCs from both honey and royal jelly were 75-120%.

  16. Lipid Discovery by Combinatorial Screening and Untargeted LC-MS/MS

    PubMed Central

    Bilgin, Mesut; Born, Petra; Fezza, Filomena; Heimes, Michael; Mastrangelo, Nicolina; Wagner, Nicolai; Schultz, Carsten; Maccarrone, Mauro; Eaton, Suzanne; Nadler, André; Wilm, Matthias; Shevchenko, Andrej

    2016-01-01

    We present a method for the systematic identification of picogram quantities of new lipids in total extracts of tissues and fluids. It relies on the modularity of lipid structures and applies all-ions fragmentation LC-MS/MS and Arcadiate software to recognize individual modules originating from the same lipid precursor of known or assumed structure. In this way it alleviates the need to recognize and fragment very low abundant precursors of novel molecules in complex lipid extracts. In a single analysis of rat kidney extract the method identified 58 known and discovered 74 novel endogenous endocannabinoids and endocannabinoid-related molecules, including a novel class of N-acylaspartates that inhibit Hedgehog signaling while having no impact on endocannabinoid receptors. PMID:27312775

  17. Contribution to the characterization of Opuntia spp. juices by LC-DAD-ESI-MS/MS.

    PubMed

    Mata, A; Ferreira, J P; Semedo, C; Serra, T; Duarte, C M M; Bronze, M R

    2016-11-01

    Opuntia spp. fruits are considered as health promoting foods due to the diversity of bioactive molecules found in these fruits. The composition in organic acids, flavonols and betalains in the Opuntia ficus-indica juice from a region of Portugal was accomplished for the first time by liquid chromatography and tandem mass spectrometry using an electrospray ionization source operating in negative and positive mode. The methodology used allowed the detection of 44 compounds, from which 32 were identified. Isorhamnetin derivatives were the dominant flavonol glycosides. A total of 9 betalains including 6 betaxanthins and 3 betacyanin were also detected in the fruit juice samples and indicaxanthin, betanin and isobetanin were the major pigments. Phenolic acid and phenylpyruvic acid derivatives were also identified. To our knowledge, it is the first time derivative compounds from piscidic acid, phenolic compounds and betalains are characterized in cactus pear juice using a single LC-DAD-ESI-MS/MS method.

  18. LC-MS/MS screen for penitrem A and roquefortine C in serum and urine samples.

    PubMed

    Tor, Elizabeth R; Puschner, Birgit; Filigenzi, Michael S; Tiwary, Asheesh K; Poppenga, Robert H

    2006-07-01

    A rapid LC-MS/MS method, using a triple quadrupole/linear ion trap mass spectrometer, was developed for determination of penitrem A and roquefortine C in serum and urine samples. Penitrem A and roquefortine C were extracted from samples with methylene chloride. The extracts were injected onto a liquid chromatograph coupled with a hybrid triple quadrupole/linear ion trap mass spectrometer. Seven replicate fortifications of serum at 0.001 microg/g (1 ppb) each of penitrem A and roquefortine C gave average recoveries of 90% with 10% CV (relative standard deviation) and 97% with 3% CV, respectively. Seven replicate fortifications of urine at 0.001 microg/g (1 ppb) each of penitrem A and roquefortine C gave average recoveries of 98% with 12% CV and 100% with 6% CV, respectively. This is the first report of a positive mass spectrometric identification and quantitation of both compounds in urine and serum samples from dog intoxication cases.

  19. HPLC-DAD-ESI-MS/MS screening of bioactive components from Rhus coriaria L. (Sumac) fruits.

    PubMed

    Abu-Reidah, Ibrahim M; Ali-Shtayeh, Mohammed S; Jamous, Rana M; Arráez-Román, David; Segura-Carretero, Antonio

    2015-01-01

    Rhus coriaria L. (sumac) is an important crop widely used in the Mediterranean basin as a food spice, and also in folk medicine, due to its health-promoting properties. Phytochemicals present in plant foods are in part responsible for these consequent health benefits. Nevertheless, detailed information on these bioactive compounds is still scarce. Therefore, the present work was aimed at investigating the phytochemical components of sumac fruit epicarp using HPLC-DAD-ESI-MS/MS in two different ionisation modes. The proposed method provided tentative identification of 211 phenolic and other phyto-constituents, most of which have not been described so far in R. coriaria fruits. More than 180 phytochemicals (tannins, (iso)flavonoids, terpenoids, etc.) are reported herein in sumac fruits for the first time. The obtained results highlight the importance of R. coriaria as a promising source of functional ingredients, and boost its potential use in the food and nutraceutical industries.

  20. Cetirizine Quantification by High-Performance Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS).

    PubMed

    Munar, Ada; Frazee, Clint; Jones, Bridgette; Garg, Uttam

    2016-01-01

    A multiple reaction monitoring (MRM), positive ion electrospray ionization, LC/MS/MS method is described for the quantification of cetirizine. The compound was isolated from human plasma by protein precipitation using acetonitrile. Cetirizine d4 was used as an internal standard. Chromatographic conditions were achieved using a C18 column and a combination of ammonium acetate, water, and methanol as the mobile phase. MRMs were: cetirizine, 389.26 → 165.16, 201.09; cetirizine d4, 393.09 → 165.15, 201.10. Calibration curves were constructed by plotting the peak area ratios of the calibrators' target MRM transition area to labeled internal standard target MRM transition area versus concentration.

  1. Evaluation of Acrylamide in Food from China by a LC/MS/MS Method

    PubMed Central

    Chen, Yong-Hong; Xia, En-Qin; Xu, Xiang-Rong; Ling, Wen-Hua; Li, Sha; Wu, Shan; Deng, Gui-Fang; Zou, Zhi-Fei; Zhou, Jing; Li, Hua-Bin

    2012-01-01

    Acrylamide is potential carcinogenic compound that possesses neurotoxicity activity. In this study, the levels of acrylamide in 123 selected food samples from China was evaluated using a LC/MS/MS method. One hundred and fifteen (115) out of 123 samples showed positive levels of acrylamide in the range of 0.41 to 4,126.26 µg/kg. Generally, the highest acrylamide levels were found in fried products, such as potato, prawn strips and rice crust, with average values of 604.27, 341.40, and 201.51 µg/kg, respectively. Heated protein-rich food also showed some acrylamide content (ranging from 2.31 to 78.57 µg/kg). The results revealed that a potential acrylamide public health risk occurred in processed snacks, as well as the food consumed daily. This study supplied new information on acrylamide content of a variety of heat-treated foods from China. PMID:23202837

  2. Current advances and strategies towards fully automated sample preparation for regulated LC-MS/MS bioanalysis.

    PubMed

    Zheng, Naiyu; Jiang, Hao; Zeng, Jianing

    2014-09-01

    Robotic liquid handlers (RLHs) have been widely used in automated sample preparation for liquid chromatography-tandem mass spectrometry (LC-MS/MS) bioanalysis. Automated sample preparation for regulated bioanalysis offers significantly higher assay efficiency, better data quality and potential bioanalytical cost-savings. For RLHs that are used for regulated bioanalysis, there are additional requirements, including 21 CFR Part 11 compliance, software validation, system qualification, calibration verification and proper maintenance. This article reviews recent advances in automated sample preparation for regulated bioanalysis in the last 5 years. Specifically, it covers the following aspects: regulated bioanalysis requirements, recent advances in automation hardware and software development, sample extraction workflow simplification, strategies towards fully automated sample extraction, and best practices in automated sample preparation for regulated bioanalysis.

  3. Determination of phenolic compounds in Yucca gloriosa bark and root by LC-MS/MS.

    PubMed

    Montoro, Paola; Skhirtladze, Alexandre; Bassarello, Carla; Perrone, Angela; Kemertelidze, Ether; Pizza, Cosimo; Piacente, Sonia

    2008-08-05

    On the basis of the biological activities shown by yuccaols and gloriosaols from Yucca schidigera and Yucca gloriosa, the content of yuccaols and gloriosaols in two different parts of Y. gloriosa (roots and bark), was determined for each single compound, and compared with phenolic determination in Y. schidigera bark, concluding that Y. gloriosa bark and roots are rich sources of phenolic derivatives structurally related to resveratrol. LC/ESIMS (liquid chromatography coupled to electrospray mass spectrometry) qualitative and an LC/ESIMS/MS (liquid chromatography coupled to tandem electrospray mass spectrometry) quantitative studies of the phenolic fraction of Y. gloriosa were performed. LC/ESIMS/MS multiple reaction monitoring (MRM) method previously described for yuccaols in Y. schidigera was applied and optimised for separation and determination of gloriosaols and yuccaols in Y. gloriosa. Due to the sensitivity and the repeatability of the assay, we suggest this method as suitable for industrial quality control of raw materials and final products.

  4. Streamlining the analytical workflow for multiplex MS/MS allergen detection in processed foods.

    PubMed

    Pilolli, Rosa; De Angelis, Elisabetta; Monaci, Linda

    2017-04-15

    Allergenic ingredients in pre-packaged foods are regulated by EU legislation mandating their inclusion on labels. In order to protect allergic consumers, sensitive analytical methods are required for detect allergen traces in different food products. As a follow-up to our previous investigations, an optimized, sensitive, label-free LC-MS/MS method for multiplex detection of five allergenic ingredients in a processed food matrix is proposed. A cookie base was chosen as a complex food matrix and home-made cookies incurred with whole egg, skimmed milk, soy flour, ground hazelnut and ground peanut were prepared at laboratory scale. In order to improve the analytical workflow both protein extraction and purification protocols were optimized and finally a sensitive streamlined SRM based analytical method for allergens detection in incurred cookies was devised. The effect of baking on the detection of selected markers was also investigated. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Identification of Penicillin G Metabolites under Various Environmental Conditions Using UHPLC-MS/MS.

    PubMed

    Aldeek, Fadi; Canzani, Daniele; Standland, Matthew; Crosswhite, Mark R; Hammack, Walter; Gerard, Ghislain; Cook, Jo-Marie

    2016-08-10

    In this work, we investigate the stability of penicillin G in various conditions including acidic, alkaline, natural acidic matrices and after treatment of citrus trees that are infected with citrus greening disease. The identification, confirmation, and quantitation of penicillin G and its various metabolites were evaluated using two UHPLC-MS/MS systems with variable capabilities (i.e., Thermo Q Exactive Orbitrap and Sciex 6500 QTrap). Our data show that under acidic and alkaline conditions, penicillin G at 100 ng/mL degrades quickly, with a determined half-life time of approximately 2 h. Penillic acid, penicilloic acid, and penilloic acid are found to be the most abundant metabolites of penicillin G. These major metabolites, along with isopenillic acid, are found when penicillin G is used for treatment of citrus greening infected trees. The findings of this study will provide insight regarding penicillin G residues in agricultural and biological applications.

  6. Alternative matrices for therapeutic drug monitoring of immunosuppressive agents using LC–MS/MS

    PubMed Central

    Ghareeb, Mwlod; Akhlaghi, Fatemeh

    2015-01-01

    Immunosuppressive drugs used in solid organ transplants typically have narrow therapeutic windows and high intra- and intersubject variability. To ensure satisfactory exposure, therapeutic drug monitoring (TDM) plays a pivotal role in any successful posttransplant maintenance therapy. Currently, recommendations for optimum immunosuppressant concentrations are based on blood/plasma measurements. However, they introduce many disadvantages, including poor prediction of allograft survival and toxicity, a weak correlation with drug concentrations at the site of action and the invasive nature of the sample collection. Thus, alternative matrices have been investigated. This paper reviews tandem-mass spectrometry (LC–MS/MS) methods used for the quantification of immunosuppressant drugs utilizing nonconventional matrices, namely oral fluids, fingerprick blood and intracellular and intratissue sampling. The advantages, disadvantages and clinical application of such alternative mediums are discussed. Additionally, sample extraction techniques and basic chromatography information regarding these methods are presented in tabulated form. PMID:25966013

  7. Alternative matrices for therapeutic drug monitoring of immunosuppressive agents using LC-MS/MS.

    PubMed

    Ghareeb, Mwlod; Akhlaghi, Fatemeh

    2015-01-01

    Immunosuppressive drugs used in solid organ transplants typically have narrow therapeutic windows and high intra- and intersubject variability. To ensure satisfactory exposure, therapeutic drug monitoring (TDM) plays a pivotal role in any successful posttransplant maintenance therapy. Currently, recommendations for optimum immunosuppressant concentrations are based on blood/plasma measurements. However, they introduce many disadvantages, including poor prediction of allograft survival and toxicity, a weak correlation with drug concentrations at the site of action and the invasive nature of the sample collection. Thus, alternative matrices have been investigated. This paper reviews tandem-mass spectrometry (LC-MS/MS) methods used for the quantification of immunosuppressant drugs utilizing nonconventional matrices, namely oral fluids, fingerprick blood and intracellular and intratissue sampling. The advantages, disadvantages and clinical application of such alternative mediums are discussed. Additionally, sample extraction techniques and basic chromatography information regarding these methods are presented in tabulated form.

  8. Human hepatic metabolism of the anxiolytic agent, RWJ-51521--API-MS/MS identification of metabolites.

    PubMed

    Wu, W N; McKown, L A; Reitz, A B

    2004-01-01

    The In vitro metabolism of the anxiolytic agent, RWJ-51521 was conducted after incubation with human hepatic S9 fraction in the presence of an NADPH-generating system. Unchanged RWJ-51521 (30% of the sample) and a total of 11 metabolites were profiled, quantified, and tentatively identified on the basis of API (ionspray)-MS/MS data. The 4 proposed metabolic pathways for RWJ-51521 are: (1) N/O-dealkylation, (2) phenylhydroxylation, (3) pyrido-oxidation, and (4) dehydration. Pathway 1 formed 2 major and 3 minor N/O-desalkyl metabolites (M1 & M3, 50%) and in conjunction with pathway 4, formed 2 moderate dehydrated metabolites (M4 & M5, 14%). Pathways 2 and 3 alone, and in conjunction with pathway 4, produced 4 minor metabolites (each < or =2%). RWJ-51521 is extensively metabolized in human hepatic S9 fraction.

  9. Determination of N-nitrosodimethylamine in drinking water by UPLC-MS/MS.

    PubMed

    Wang, Wanfeng; Hu, Jianying; Yu, Jianwei; Yang, Min

    2010-01-01

    The method for detecting N-nitrosodimethylamine (NDMA) in drinking water using ultra performance liquid chromatography (UPLC) coupled with tandem mass spectrometry (MS/MS) was improved by optimizing the clean-up procedure to remove the matrix interference in pretreatment process, and was then applied to a survey of NDMA in both raw and finished water samples from five water treatment plants in South China. The NDMA concentrations ranged from 4.7 to 15.1 ng/L in raw water samples, and from 4.68 to 46.9 ng/L in finished water. The NDMA concentration in raw water was found to be related with nitrite concentration, and during the treatment, the NDMA concentration increased following ozonation but decreased after subsequent activated carbon treatment.

  10. Free amino acid profiling in the giant puffball mushroom (Calvatia gigantea) using UPLC-MS/MS.

    PubMed

    Kıvrak, İbrahim; Kıvrak, Şeyda; Harmandar, Mansur

    2014-09-01

    Wild edible and medicinal mushroom, Calvatia gigantea, was quantitatively analyzed for the determination of its free amino acids using ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The concentrations of total free amino acids, essential and non-essential amino acids were 199.65 mg/100 g, 113.69 mg/100 g, and 85.96 mg/100 g in C. gigantea, respectively. This study showed that C. gigantea, so called a giant puffball mushroom, has free amino acids content. The essential amino acids: tryptophan, isoleucine, valine, phenylalanine, leucine, threonine, lysine, histidine, methionine, and the non-essential amino acids: tyrosine, 4-hyrdroxy proline, arginine, proline, glycine, serine, alanine, glutamine, glutamic acid, aspargine, aspartic acid were detected.

  11. Multiresidue determination of triarylmethane and phenothiazine dyes in fish tissues by LC-MS/MS.

    PubMed

    Tarbin, Jonathan A; Chan, Danny; Stubbings, George; Sharman, Matthew

    2008-09-12

    The occurrence of residues of malachite green and its leuco-metabolite in tissues of farmed fish for human consumption have long been of concern and there is extensive literature on methods of analysis and surveillance for these compounds. Recently, concern has been expressed that the use of other related compounds in place of malachite green may go undetected. This paper describes a new method for extending the range of triarylmethane and related phenothiazine dyes that can be detected in fish. In this procedure 13 parent compounds are monitored, with any potential leuco-forms being oxidized back to the parent prior to determination. The method utilizes a buffer-acetonitrile extraction followed by liquid-liquid extraction. Oxidant is added and the extracts further purified by cation exchange chromatography. Final determination is carried out using LC-MS/MS. The method has been validated to the standards of Commission Decision 2002/657/EC.

  12. Rapid and reproducible determination of active gibberellins in citrus tissues by UPLC/ESI-MS/MS.

    PubMed

    Manzi, Matías; Gómez-Cadenas, Aurelio; Arbona, Vicent

    2015-09-01

    Phytohormone determination is crucial to explain the physiological mechanisms during growth and development. Therefore, rapid and precise methods are needed to achieve reproducible determination of phytohormones. Among many others, gibberellins (GAs) constitute a family of complex analytes as most of them share similar structure and chemical properties although only a few hold biological activity (namely GA1; GA3; GA4 and GA7). A method has been developed to extract GAs from plant tissues by mechanical disruption using ultrapure water as solvent and, in this way, ion suppression was reduced whereas sensitivity increased. Using this methodology, the four active GAs were separated and quantified by UPLC coupled to MS/MS using the isotope-labeled internal standards [(2)H2]-GA1 and [(2)H2]-GA4. To sum up, the new method provides a fast and reproducible protocol to determine bioactive GAs at low concentrations, using minimal amounts of sample and reducing the use of organic solvents.

  13. STS-31 MS McCandless and MS Sullivan during JSC WETF underwater simulation

    NASA Technical Reports Server (NTRS)

    1990-01-01

    This overall view shows STS-31 Mission Specialist (MS) Bruce McCandless II (left) and MS Kathryn D. Sullivan making a practice space walk in JSC's Weightless Environment Training Facility (WETF) Bldg 29 pool. McCandless works with a mockup of the remote manipulator system (RMS) end effector which is attached to a grapple fixture on the Hubble Space Telescope (HST) mockup. Sullivan manipulates HST hardware on the Support System Module (SSM) forward shell. SCUBA-equipped divers monitor the extravehicular mobility unit (EMU) suited crewmembers during this simulated extravehicular activity (EVA). No EVA is planned for the Hubble Space Telescope (HST) deployment, but the duo has trained for contingencies which might arise during the STS-31 mission aboard Discovery, Orbiter Vehicle (OV) 103. Photo taken by NASA JSC photographer Sheri Dunnette.

  14. Building and searching tandem mass (MS/MS) spectral libraries for peptide identification in proteomics.

    PubMed

    Lam, Henry; Aebersold, Ruedi

    2011-08-01

    Spectral library searching is an emerging approach in peptide identifications from tandem mass spectra, a critical step in proteomic data analysis. In spectral library searching, a spectral library is first meticulously compiled from a large collection of previously observed peptide MS/MS spectra that are conclusively assigned to their corresponding amino acid sequence. An unknown spectrum is then identified by comparing it to all the candidates in the spectral library for the most similar match. This review discusses the basic principles of spectral library building and searching, describes its advantages and limitations, and provides a primer for researchers interested in adopting this new approach in their data analysis. It will also discuss the future outlook on the evolution and utility of spectral libraries in the field of proteomics.

  15. Direct analysis of underivatized amino acids in plant extracts by LC-MS-MS.

    PubMed

    Thiele, Björn; Stein, Nadine; Oldiges, Marco; Hofmann, Diana

    2012-01-01

    In this chapter, we describe a method for quantification of 20 proteinogenic amino acids as well as 13 (15)N-labeled amino acids by liquid chromatography-mass spectrometry without the need for derivatization and use of organic solvents. Analysis of the underivatized amino acids is performed by liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS-MS) in the positive ESI mode. Separation is achieved on a strong cation exchange (SCX) column (Luna 5 μm SCX 100 Å) with 30 mM ammonium acetate in water (A) and 5% acetic acid in water (B). Quantification is accomplished by use of d(5)-phenylalanine as internal standard achieving limits of detection of 0.1-3.0 μM. The method was successfully applied for the determination of proteinogenic and (15)N-labeled amino acids in plant extracts.

  16. Quantitation of sweet steviol glycosides by means of a HILIC-MS/MS-SIDA approach.

    PubMed

    Well, Caroline; Frank, Oliver; Hofmann, Thomas

    2013-11-27

    Meeting the rising consumer demand for natural food ingredients, steviol glycosides, the sweet principle of Stevia rebaudiana Bertoni (Bertoni), have recently been approved as food additives in the European Union. As regulatory constraints require sensitive methods to analyze the sweet-tasting steviol glycosides in foods and beverages, a HILIC-MS/MS method was developed enabling the accurate and reliable quantitation of the major steviol glycosides stevioside, rebaudiosides A-F, steviolbioside, rubusoside, and dulcoside A by using the corresponding deuterated 16,17-dihydrosteviol glycosides as suitable internal standards. This quantitation not only enables the analysis of the individual steviol glycosides in foods and beverages but also can support the optimization of breeding and postharvest downstream processing of Stevia plants to produce preferentially sweet and least bitter tasting Stevia extracts.

  17. Comparison of MS/MS Methods for Characterization of DNA/cisplatin Adducts

    PubMed Central

    Xu, Zhe; Shaw, Jared B.; Brodbelt, Jennifer S.

    2012-01-01

    The development of activation/dissociation techniques such as ultraviolet photodissociation (UVPD), infrared multiphoton dissociation (IRMPD) and electron transfer dissociation (ETD) as alternatives to collision induced dissociation (CID) has extended the range of strategies for characterizing biologically relevant molecules. Here, we describe a comprehensive comparison of CID, IRMPD, UVPD, ETD and hybrid processes termed ETcaD and ET-IRMPD (and analogous hybrid methods in the negative mode NETcaD and NET-IRMPD) for generating sequence specific-fragment ions and allowing adduction sites to be pinpointed for DNA/cisplatin adducts. Among the six MS/MS methods, the numerous products generated by the IRMPD and UVPD techniques resulted in the most specific and extensive backbone cleavages. We conclude that IRMPD and UVPD methods generally offer the best characteristics for pinpointing the cisplatin adduction sites in the fragment-rich spectra. PMID:23264150

  18. Screening assay of residual antibiotics in livestock samples by LC-MS/MS.

    PubMed

    Nakajima, Takayuki; Sasamoto, Takeo; Hayashi, Hiroshi; Kanda, Maki; Takeba, Kazue; Kanai, Setsuko; Kusano, Tomoko; Matsushima, Yoko; Takano, Ichiro

    2012-01-01

    A LC-MS/MS screening assay of multi-class antibiotics was developed for 19 residual antibiotics in livestock samples. Sample preparation employed the QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) approach using 0.5% formic acid in acetonitrile-methanol (8 : 2), with salting-out using magnesium sulfate, trisodium citrate and sodium chloride. Recovery values from 5 different livestock samples ranged from 45.5 to 121.6%, and the RSDs were under 18% at two concentration levels. The limit of quantification values of 19 analytes were under 10 µg/kg in all livestock samples, and the procedure can detect almost all analytes under the MRL. Screening capability was confirmed by employing spiked samples. This new screening assay for residual antibiotics in livestock samples is expected to be useful for routine laboratory tests.

  19. Determination of testosterone esters and nortestosterone esters in animal blood serum by LC-MS/MS.

    PubMed

    Rejtharová, Martina; Rejthar, Libor; Čačková, Katarína

    2017-10-05

    A sensitive and robust confirmatory method for determination of steroid esters in blood serum is essential for reliable monitoring of possible illegal use of steroid hormones as growth promoters in meat production. A previously used sample preparation methodology was improved. The procedure consists of protein precipitation and removal of phospholipids by dispersive SPE Supel(TM) QuE Z-Sep (Sigma-Aldrich) followed by clean-up on alumina column and LC-MS/MS measurement. The modified method has been validated according to Commission Decision 2002/657/EC. Validation parameters for determination of six testosterone esters and five nortestosterone esters in bovine and porcine blood serum are presented in this manuscript. Decision limits for all analytes were observed in the range 10 - 20 pg mL(-1). The method described in this manuscript is considerably robust for bovine and porcine serum analyses and can be applied both for screening and confirmatory determination in routine residue monitoring.

  20. A widely applicable plasma renin activity assay by LC-MS/MS with offline solid phase extraction.

    PubMed

    Owen, Laura J; Adaway, Joanne; Morris, Karen; Lockhart, Stephen; Keevil, Brian G

    2014-05-01

    The measurement of plasma renin activity using LC-MS/MS is an attractive alternative to radioimmunoassay techniques. A published method for renin activity by LC-MS/MS uses equipment that is not available in all LC-MS/MS laboratories. Here, we present an offline modification to allow users of LC-MS/MS to perform this analysis without specialist equipment. Samples were prepared in duplicate and incubated for 6.5 h and 24 h. Solid phase extraction was performed offline using Waters Oasis MAX ion-exchange 96-well plate. A method comparison was performed between this assay and a previously published assay using on-line solid phase extraction. The offline method for plasma rennin activity gave similar results to the on-line method across the concentration range. Analytical performance was also found to be comparable and the use of a 24 h incubation for low samples was also deemed unnecessary. The method described is an acceptable alternative to a previously published assay which does not require the use of highly specialist equipment and will be applicable to the majority of LC-MS/MS users.

  1. Identification and Quantification of Loline-Type Alkaloids in Endophyte-Infected Grasses by LC-MS/MS.

    PubMed

    Adhikari, Khem B; Boelt, Birte; Fomsgaard, Inge S

    2016-08-10

    Lolines, fungal metabolites of the grass-endophyte association, were identified and quantified using newly developed LC-MS/MS methods in endophyte-infected grasses belonging to the Lolium and Festuca genera after extraction with three different solvents using two extraction methods. The shaking extraction method with isopropanol/water was superior to the other methods due to its high sensitivity, high accuracy (recovery within or close to the range of 80-120%), and high precision (coefficient of variation of <10%). Seven loline alkaloids were identified and quantified using our newly established LC-MS/MS methods, and N-formylloline was the most abundant (5 mg/g dry matter), followed by N-acetylloline. These LC-MS/MS methods used the shortest sample handling time and the fewest sample preparation steps and proved to be good alternatives to existing GC and GC-MS analytical methods without compromising analytical efficiency. In conclusion, we developed for the first time a highly sensitive quantitative LC-MS/MS analytical method for the accurate and reproducible quantification and a LightSight-assisted LC-QTRAP/MS qualitative method for the tentative identification of loline-type alkaloids in endophyte-infected grasses.

  2. Development and validation of an LC-MS/MS sulfonylurea assay for hypoglycemia cases in the emergency department.

    PubMed

    Yang, He S; Wu, Alan H B; Johnson-Davis, Kamisha L; Lynch, Kara L

    2016-02-15

    Sulfonylureas are antidiabetic agents widely prescribed for the treatment of type-II diabetes. Detection of the presence of sulfonylureas in cases of unexplained hypoglycemia rules out other underlying pathophysiological conditions. The goal of this study was to develop and validate a qualitative liquid chromatography tandem mass spectrometry (LC-MS/MS) assay for the rapid identification of sulfonylureas in serum. An LC-MS/MS assay was developed using an Agilent HPLC with an AB Sciex 3200 LC-MS/MS operating in ESI positive mode. Linearity, LOD, precision, matrix effect, recovery, carry-over and stability of the final method were evaluated for method validation. Concordance with another clinically validated LC-MS/MS method was evaluated using remnant samples from patients prescribed a sulfonylurea. The assay performed well with all validation data meeting pre-determined criteria. The method comparison study showed a correlation coefficient of 0.99 for glipizide, the most common sulfonylurea, despite both methods being validated as qualitative methods. To date the validated assay has been utilized in 19 cases of unexplained hypoglycemia presenting to the emergency department, in which 5 were sulfonylurea positive. We have developed a rapid and sensitive LC-MS/MS sulfonylurea assay, and utilized this assay to assist in the differential diagnosis of unexplained hypoglycemia. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. LC-MS/MS Peptide Mapping with Automated Data Processing for Routine Profiling of N-Glycans in Immunoglobulins

    NASA Astrophysics Data System (ADS)

    Shah, Bhavana; Jiang, Xinzhao Grace; Chen, Louise; Zhang, Zhongqi

    2014-06-01

    Protein N-Glycan analysis is traditionally performed by high pH anion exchange chromatography (HPAEC), reversed phase liquid chromatography (RPLC), or hydrophilic interaction liquid chromatography (HILIC) on fluorescence-labeled glycans enzymatically released from the glycoprotein. These methods require time-consuming sample preparations and do not provide site-specific glycosylation information. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) peptide mapping is frequently used for protein structural characterization and, as a bonus, can potentially provide glycan profile on each individual glycosylation site. In this work, a recently developed glycopeptide fragmentation model was used for automated identification, based on their MS/MS, of N-glycopeptides from proteolytic digestion of monoclonal antibodies (mAbs). Experimental conditions were optimized to achieve accurate profiling of glycoforms. Glycan profiles obtained from LC-MS/MS peptide mapping were compared with those obtained from HPAEC, RPLC, and HILIC analyses of released glycans for several mAb molecules. Accuracy, reproducibility, and linearity of the LC-MS/MS peptide mapping method for glycan profiling were evaluated. The LC-MS/MS peptide mapping method with fully automated data analysis requires less sample preparation, provides site-specific information, and may serve as an alternative method for routine profiling of N-glycans on immunoglobulins as well as other glycoproteins with simple N-glycans.

  4. Quantitative lipopolysaccharide analysis using HPLC/MS/MS and its combination with the limulus amebocyte lysate assay[S

    PubMed Central

    Pais de Barros, Jean-Paul; Gautier, Thomas; Sali, Wahib; Adrie, Christophe; Choubley, Hélène; Charron, Emilie; Lalande, Caroline; Le Guern, Naig; Deckert, Valérie; Monchi, Mehran; Quenot, Jean-Pierre; Lagrost, Laurent

    2015-01-01

    Quantitation of plasma lipopolysaccharides (LPSs) might be used to document Gram-negative bacterial infection. In the present work, LPS-derived 3-hydroxymyristate was extracted from plasma samples with an organic solvent, separated by reversed phase HPLC, and quantitated by MS/MS. This mass assay was combined with the limulus amebocyte lysate (LAL) bioassay to monitor neutralization of LPS activity in biological samples. The described HPLC/MS/MS method is a reliable, practical, accurate, and sensitive tool to quantitate LPS. The combination of the LAL and HPLC/MS/MS analyses provided new evidence for the intrinsic capacity of plasma lipoproteins and phospholipid transfer protein to neutralize the activity of LPS. In a subset of patients with systemic inflammatory response syndrome, with documented infection but with a negative plasma LAL test, significant amounts of LPS were measured by the HPLC/MS/MS method. Patients with the highest plasma LPS concentration were more severely ill. HPLC/MS/MS is a relevant method to quantitate endotoxin in a sample, to assess the efficacy of LPS neutralization, and to evaluate the proinflammatory potential of LPS in vivo. PMID:26023073

  5. Analysis of biofluids by paper spray MS: advances and challenges.

    PubMed

    Manicke, Nicholas E; Bills, Brandon J; Zhang, Chengsen

    2016-03-01

    Paper spray MS is part of a cohort of ambient ionization or direct analysis methods that seek to analyze complex samples without prior sample preparation. Extraction and electrospray ionization occur directly from the paper substrate upon which a dried matrix spot is stored. Paper spray MS is capable of detecting drugs directly from dried blood, plasma and urine spots at the low ng/ml to pg/ml levels without sample preparation. No front end separation is performed, so MS/MS or high-resolution MS is required. Here, we discuss paper spray methodology, give a comprehensive literature review of the use of paper spray MS for bioanalysis, discuss technological advancements and variations on this technique and discuss some of its limitations.

  6. Use of Tricaine Methanesulfonate (MS222) for Euthanasia of Reptiles

    PubMed Central

    Conroy, CJ; Papenfuss, T; Parker, J; Hahn, NE

    2009-01-01

    Tricaine methanesulfonate (MS222) injected into the intracoelomic cavity of reptiles was evaluated as a chemical euthanasia method. Three western fence lizards, 2 desert iguanas, 4 garter snakes, and 6 geckos were euthanized by intracoelomic injection of 250 to 500 mg/kg of 0.7% to 1% sodium-bicarbonate–buffered MS222 solution followed by intracoelomic injection of 0.1 to 1.0 ml unbuffered 50% (v/v) MS222 solution. A simple 2-stage protocol for euthanasia of reptiles by using MS222 is outlined. In addition, the conditions for safe use of MS222 are discussed. MS222 offers an alternative to sodium pentobarbital for euthanasia of reptiles. PMID:19245747

  7. Comparison of GC/MS and LC/MS methods for the analysis of propofol and its metabolites in urine.

    PubMed

    Lee, Sun Young; Park, Na-Hyun; Jeong, Eun-Kyung; Wi, Jae-Woo; Kim, Chang-Ju; Kim, Jin Young; In, Moon Kyo; Hong, Jongki

    2012-07-01

    Gas chromatography-mass spectrometry (GC/MS) and liquid chromatography-mass spectrometry (LC/MS) were compared for their capacity to metabolite identification, sensitivity, and speed of analysis for propofol and its metabolites in urine samples. Acidic hydrolysis, liquid-liquid extraction (LLE), and trimethylsilyl (TMS) derivatization procedures were applied for GC/MS analysis. The LC/MS analysis used a simple sample pretreatment based on centrifugation and dilution. Propofol and four metabolites were successfully analyzed by GC/MS following TMS derivatization. One compound, di-isopropanolphenol was tentatively characterized as a new metabolite observed for the first time in human urine. The TMS derivatization greatly improved the chromatographic properties and detection sensitivity, especially for hydroxylated metabolites. The lower limits of quantitation (LLOQ) of propofol were about 325 and 0.51 ng/mL for the GC/MS scan mode and selected ion monitoring (SIM) mode, respectively. In addition, five conjugated propofol metabolites were successfully analyzed by LC-MS/MS in negative ion mode. The detection sensitivity for these conjugated metabolites could be greatly enhanced by the addition of triethylamine to the mobile phase without any loss of LC resolution capacity. The LLOQs of propofol-glucuronide (PG) were about 1.17 and 2.01 ng/mL for the LC-MS-selected ion monitoring (SIM) and multiple reaction monitoring (MRM) mode, respectively. Both GC/MS and LC/MS methods sensitively detected nine metabolites of propofol and could be used to provide complementary data for the reasonable propofol metabolism study. Urinary excretion profiles for propofol and its metabolites following administration to human were suggested based on the total ion chromatograms obtained by GC/MS and LC/MS methods, respectively. Copyright © 2012 Elsevier B.V. All rights reserved.

  8. LC-MS/MS Analysis Unravels Deep Oxidation of Manganese Superoxide Dismutase in Kidney Cancer

    PubMed Central

    Zhao, Zuohui; Azadzoi, Kazem M.; Choi, Han-Pil; Jing, Ruirui; Lu, Xin; Li, Cuiling; Wang, Fengqin; Lu, Jiaju; Yang, Jing-Hua

    2017-01-01

    Manganese superoxide dismutase (MNSOD) is one of the major scavengers of reactive oxygen species (ROS) in mitochondria with pivotal regulatory role in ischemic disorders, inflammation and cancer. Here we report oxidative modification of MNSOD in human renal cell carcinoma (RCC) by the shotgun method using data-dependent liquid chromatography tandem mass spectrometry (LC-MS/MS). While 5816 and 5571 proteins were identified in cancer and adjacent tissues, respectively, 208 proteins were found to be up- or down-regulated (p < 0.05). Ontological category, interaction network and Western blotting suggested a close correlation between RCC-mediated proteins and oxidoreductases such as MNSOD. Markedly, oxidative modifications of MNSOD were identified at histidine (H54 and H55), tyrosine (Y58), tryptophan (W147, W149, W205 and W210) and asparagine (N206 and N209) residues additional to methionine. These oxidative insults were located at three hotspots near the hydrophobic pocket of the manganese binding site, of which the oxidation of Y58, W147 and W149 was up-regulated around three folds and the oxidation of H54 and H55 was detected in the cancer tissues only (p < 0.05). When normalized to MNSOD expression levels, relative MNSOD enzymatic activity was decreased in cancer tissues, suggesting impairment of MNSOD enzymatic activity in kidney cancer due to modifications. Thus, LC-MS/MS analysis revealed multiple oxidative modifications of MNSOD at different amino acid residues that might mediate the regulation of the superoxide radicals, mitochondrial ROS scavenging and MNSOD activity in kidney cancer. PMID:28165386

  9. Determination of cannabinoids in whole blood by UPLC-MS-MS.

    PubMed

    Jamey, Carole; Szwarc, Esther; Tracqui, Antoine; Ludes, Bertrand

    2008-06-01

    An ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS-MS) method was developed and validated for the simultaneous determination of Delta(9)-tetrahydrocannabinol (THC), 11-hydroxy-Delta(9)-tetrahydrocannabinol (11-OH-THC), and 11-nor-9-carboxy-Delta(9)-tetrahydrocannabinol (THC-COOH) in whole blood. Samples were prepared by protein precipitation followed by solid-phase extraction. Data were acquired using positive electrospray ionization and multiple reaction monitoring. Two transitions were selected for THC (m/z 315.0 > 193.0 and m/z 315.0 > 122.7) and THC-COOH (m/z 345.0 > 299.0 and m/z 345.0 > 327.0), and one transition was chosen for 11-OH-THC (m/z 331.0 > 313.0). Deuterated analogues of each analyte were used as internal standards for quantification. Run time was 10 min. Limits of quantification (LOQ) were 0.05 ng/mL for THC, 0.1 ng/mL for 11-OH-THC, and 0.2 ng/mL for THC-COOH. Linearity was established from LOQ to 50 ng/mL for each substance (r(2) always > 0.999). Accuracy ranged from 96 to 106%, and imprecision was less than 10% for all analytes. The UPLC-MS-MS method was found to be sensitive, specific, and rapid because it requires no derivatization step. It can be an alternative to gas chromatography-mass spectrometry for the determination of cannabinoids in whole blood.

  10. Stars of type MS with evidence of white dwarf companions. [IUE, Main Sequence (MS)

    NASA Technical Reports Server (NTRS)

    Peery, Benjamin F., Jr.

    1986-01-01

    A search for white dwarf companions of MS-type stars was conducted, using IUE. The overendowments of these stars in typical S-process nuclides suggest that they, like the Ba II stars, may owe their peculiar compositions to earlier mass transfer. Short-wavelength IUE spectra show striking emission line variability in HD35155, HD61913, and 4 Ori; HD35155 and 4 Ori show evidence of white dwarf companions.

  11. Methylmalonic acid quantification in low serum volumes by UPLC-MS/MS.

    PubMed

    Pedersen, Theresa L; Keyes, William R; Shahab-Ferdows, Setareh; Allen, Lindsay H; Newman, John W

    2011-06-01

    Methylmalonic acid (MMA) is a metabolic intermediate transformed to succinic acid (SA) by a vitamin B(12)-dependent catalytic step, and is broadly used as a clinical biomarker of functional vitamin B12 status. However, reported methods use between 100 and 1000 μL of serum or plasma making them sub-optimal for sample-limited studies, including those with neonates and infants. LC-MS/MS based protocols to measure MMA as n-butyl esters in the presence of tri-deuterated MMA (MMA-d(3)) were modified for use with 25 μL of human serum by scaling down sample processing volumes and analysis by UPLC-MS/MS. Plasma-based calibration solutions were found to be unnecessary, and chromatographic resolution and peak shape of SA and MMA was optimized in <4 min with isocratic 53:47 methanol/1.67 mM (pH 6.5) ammonium formate. Additionally, 1-cyclohexyl-urido-3-dodecanoic acid (CUDA) was included as internal standard allowing direct assessment of MMA recovery. Sample concentrations in the low normal range produced a signal:noise of >100:1. MMA intra- and inter-assay variability was under 10%. MMA-d(3) surrogate recovery averaged 93±14%. MMA stability exceeded three years in frozen samples and was unaffected by up to five freeze/thaw cycles. In conclusion, we report that methylmalonic acid can be measured with 25 μL of serum using water based standards. The assay signal:noise per concentration indicates that the method could perform as implemented with as little as 5 μL of serum. The reported method is applicable for studies of functional B12 status in sample limited experiments including investigations of nutritional status in neonates and in studies where low normal MMA levels are expected.

  12. LC-MS/MS screening method for designer amphetamines, tryptamines, and piperazines in serum.

    PubMed

    Wohlfarth, Ariane; Weinmann, Wolfgang; Dresen, Sebastian

    2010-04-01

    Since the late 1990s and early 2000s, derivatives of well-known designer drugs as well as new psychoactive compounds have been sold on the illicit drug market and have led to intoxications and fatalities. The LC-MS/MS screening method presented covers 31 new designer drugs as well as cathinone, methcathinone, phencyclidine, and ketamine which were included to complete the screening spectrum. All but the last two are modified molecular structures of amphetamine, tryptamine, or piperazine. Among the amphetamine derivatives are cathinone, methcathinone, 3,4-DMA, 2,5-DMA, DOB, DOET, DOM, ethylamphetamine, MDDMA, 4-MTA, PMA, PMMA, 3,4,5-TMA, TMA-6 and members of the 2C group: 2C-B, 2C-D, 2C-H, 2C-I, 2C-P, 2C-T-2, 2C-T-4, and 2C-T-7. AMT, DPT, DiPT, MiPT, DMT, and 5MeO-DMT are contained in the tryptamine group, BZP, MDBP, TFMPP, mCPP, and MeOPP in the piperazine group. Using an Applied Biosystems LC-MS/MS API 365 TurboIonSpray it is possible to identify all 35 substances. After addition of internal standards and mixed-mode solid-phase extraction the analytes are separated using a Synergi Polar RP column and gradient elution with 1 mM ammonium formate and methanol/0.1% formic acid as mobile phases A and B. Data acquisition is performed in MRM mode with positive electro spray ionization. The assay is selective for all tested substances. Limits of detection were determined by analyzing S/N-ratios and are between 1.0 and 5.0 ng/mL. Matrix effects lie between 65% and 118%, extraction efficiencies range from 72% to 90%.

  13. Highly sensitive simultaneous quantification of estrogenic tamoxifen metabolites and steroid hormones by LC-MS/MS.

    PubMed

    Johänning, Janina; Heinkele, Georg; Precht, Jana C; Brauch, Hiltrud; Eichelbaum, Michel; Schwab, Matthias; Schroth, Werner; Mürdter, Thomas E

    2015-09-01

    Tamoxifen is a mainstay in the treatment of estrogen receptor-positive breast cancer and is metabolized to more than 30 different compounds. Little is known about in vivo concentrations of estrogenic metabolites E-metabolite E, Z-metabolite E, and bisphenol and their relevance for tamoxifen efficacy. Therefore, we developed a highly sensitive HPLC-ESI-MS/MS quantification method for tamoxifen metabolites bisphenol, E-metabolite E, and Z-metabolite E as well as for the sex steroid hormones estradiol, estrone, testosterone, androstenedione, and progesterone. Plasma samples were subjected to protein precipitation followed by solid phase extraction. Upon derivatization with 3-[(N-succinimide-1-yl)oxycarbonyl]-1-methylpyridinium iodide, all analytes were separated on a sub-2-μm column with a gradient of acetonitrile in water with 0.1 % of formic acid. Analytes were detected on a triple-quadrupole mass spectrometer with positive electrospray ionization in the multiple reaction monitoring mode. Our method demonstrated high sensitivity, accuracy, and precision. The lower limits of quantification were 12, 8, and 25 pM for bisphenol, E-metabolite E, and Z-metabolite E, respectively, and 4 pM for estradiol and estrogen, 50 pM for testosterone and androstenedione, and 25 pM for progesterone. The method was applied to plasma samples of postmenopausal patients taken at baseline and under tamoxifen therapy. Graphical Abstract Sample preparation and derivatization for highly sensitive quantification of estrogenic tamoxifen metabolites and steroid hormones by HPLC-MS/MS.

  14. Analysis and Exposure Assessment of Perchlorate in Korean Dairy Products with LC-MS/MS

    PubMed Central

    Oh, Sung-Hee; Lee, Ji-Woo; Mandy, Pawlas

    2011-01-01

    Objectives Perchlorate is an emerging contaminant that is found everywhere, including various foods. Perchlorate is known to disturb the production of thyroid hormones and leads to mental disorders in fetuses and infants, as well as metabolic problems in adults. In this study, we attempted to establish an LC-MS/MS method for measuring perchlorate in dairy products and used this developed method to investigate perchlorate levels in Korean milk and yogurt samples. Methods The developed method of perchlorate analysis requires a shaker and 1% acetic acid/acetonitrile as the extracting solvent. Briefly, the samples were extracted and then centrifuged (4000 rpm, 1hour), and the supernatant was then passed through a Envi™ Carb SPE cartridge that had been prewashed sequentially with 6 mL of acetonitrile and 6 mL of 1% acetic acid in water. The final volume of the sample extract was adjusted to 40 mL with reagent water and the final sample was filtered through a 0.20-µm pore size PTFE (Polytetrafluoroethylene) syringe filter prior to LC-MS/MS. Results The average levels of perchlorate in milk and yogurt samples were 5.63 ± 3.49 µg/L and 3.65 ± 2.42 µg/L, respectively. The perchlorate levels observed in milk samples in this study were similar to those reported from China, Japan, and the United States. Conclusions The exposure of Koreans to perchlorate through the consumption of dairy products was calculated based on the results of this study. For all age groups, the calculated exposure to perchlorate was below the reference of dose (0.7 µg/kg-day) proposed by the National Academy of Science, USA, but the perchlorate exposure of children was higher than that of adults. Therefore, further investigation of perchlorate in other food samples is needed to enable a more exact assessment of exposure of children to perchlorate. PMID:22125772

  15. STS-47 MS Davis and MS/PLC Lee inspect SLJ Rack 5 during KSC training

    NASA Technical Reports Server (NTRS)

    1992-01-01

    STS-47 Endeavour, Orbiter Vehicle (OV) 105, Mission Specialist N. Jan Davis and MS and Payload Commander (PLC) Mark C. Lee, wearing clean suits, check latches on the Spacelab Japan (SLJ) Rack 5 Adult Frog Compartment during an inspection of the SLJ module which is currently undergoing preflight processing in a high bay of the Kennedy Space Center's (KSC's) Orbiter Processing Facility (OPF). View provided by KSC with alternate KSC number KSC-92PC-1643.

  16. STS-47 MS Davis and MS/PLC Lee examine SLJ Rack 10 during KSC inspection

    NASA Technical Reports Server (NTRS)

    1992-01-01

    STS-47 Endeavour, Orbiter Vehicle (OV) 105, Mission Specialist N. Jan Davis and MS and Payload Commander (PLC) Mark C. Lee, wearing clean suits, examine NASDA Material Sciences control panel on Spacelab Japan (SLJ) Rack 10 during an inspection of the SLJ module. The module is currently undergoing preflight processing in a high bay of the Kennedy Space Center's (KSC's) Orbiter Processing Facility (OPF). View provided by KSC with alternate KSC number KSC-92PC-1644.

  17. Quantitative determination of vitamin D metabolites in plasma using UHPLC-MS/MS.

    PubMed

    Ding, Shujing; Schoenmakers, Inez; Jones, Kerry; Koulman, Albert; Prentice, Ann; Volmer, Dietrich A

    2010-09-01

    Vitamin D is an important determinant of bone health at all ages. The plasma concentrations of 25-hydroxy vitamin D (25-OH D) and other metabolites are used as biomarkers for vitamin sufficiency and function. To allow for the simultaneous determination of five vitamin D metabolites, 25-OH D(3), 25-OH D(2), 24,25-(OH)(2) D(3), 1,25-(OH)(2) D(3), and 1,25-(OH)(2) D(2), in low volumes of human plasma, an assay using ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) was established. Plasma samples were spiked with isotope-labeled internal standards and pretreated using protein precipitation, solid-phase extraction (SPE) and a Diels-Alder derivatization step with 4-phenyl-1,2,4-triazoline-3,5-dione. The SPE recovery rates ranged from 55% to 85%, depending on the vitamin D metabolite; the total sample run time was <5 min. Mass spectrometry was conducted using positive ion electrospray ionization in the multiple reaction monitoring mode on a quadrupole-quadrupole-linear ion trap instrument after pre-column addition of methylamine to increase the ionization efficiency. The intra- and inter-day relative standard deviations were 1.6-4.1% and 3.7-6.8%, respectively. The limit of quantitation for these compounds was determined to be between 10 and 20 pg/mL. The 25-OH D results were compared with values obtained for reference materials (DEQAS). In addition, plasma samples were analyzed with two additional Diasorin antibody assays. All comparisons with conventional methods showed excellent correlations (r(2) = 0.9738) for DEQAS samples, demonstrating the high degree of comparability of the new UHPLC-MS/MS technique to existing methods.

  18. [LC-MS/MS assay of methylphenidate: stability and pharmacokinetics in human].

    PubMed

    Luo, Xue-Mei; Ding, Li; Gu, Xin; Jiang, Li-Yuan; Dong, Xin

    2014-01-01

    The study aims to solve the instability problem of methylphenidate (MPH) in plasma, and establish a LC-MS/MS method for simultaneous determining of MPH in human plasma. The stabilities of MPH in different media were studied, and the degradation characteristics of MPH in these media were also investigated by HPLC and LC-MS/MS. To a 200 microL aliquot of freshly collected plasma sample, 10 microL 2% formic acid was added immediately to prevent the hydrolysis of MPH in human plasma samples. Chromatographic separation was performed on a Sapphire C18 column using the mobile phase of methanol - 5 mmol.L-1 ammonium acetate buffer solution containing 0.1% formic acid (46 : 54). MPH was quantified by tandem mass spectrometry operating in positive electrospray ionization mode with multiple reaction monitoring. The detection used the transitions of protonated molecules at m/z 234.2-->84.1 for MPH and m/z 260.3-->183.1 for propranolol (IS), separately. The intra- and inter-assay precisions were all below 5.0%. The accuracies were all in standard ranges. The linear calibration curve was obtained in the concentration range of 0.035-40 ng.mL-1. The methods fulfilled the demand. The method was used to determine the concentration of MPH in human plasma after a single dose of 36 mg MPH tablet to 6 healthy Chinese volunteers. The method is suitable for the precisely determination of MPH and for pharmacokinetic study of MPH in human plasma.

  19. LC-MS/MS detection of unaltered glucuronoconjugated metabolites of metandienone.

    PubMed

    Esquivel, Argitxu; Pozo, Oscar J; Garrostas, Lorena; Balcells, Georgina; Gómez, Cristina; Kotronoulas, Aristotelis; Joglar, Jesús; Ventura, Rosa

    2016-05-30

    The aim of this study was to evaluate the direct detection of glucuronoconjugated metabolites of metandienone (MTD) and their detection times. Metabolites resistant to enzymatic hydrolysis were also evaluated. Based on the common mass spectrometric behaviour of steroid glucuronides, three liquid chromatography-tandem mass spectrometry (LC-MS/MS) strategies were applied for the detection of unpredicted and predicted metabolites: precursor ion scan (PI), neutral loss scan (NL), and theoretical selected reaction monitoring (SRM) methods. Samples from four excretion studies of MTD were analyzed for both the detection of metabolites and the establishment of their detection times. Using PI and NL methods, seven metabolites were observed in post-administration samples. SRM methods allowed for the detection of 13 glucuronide metabolites. The detection times, measured by analysis with an SRM method, were between 1 and 22 days. The metabolite detected for the longest time was 18-nor-17β-hydroxymethyl-17α-methyl-5β-androsta-1,4,13-triene-3-one-17-glucuronide. One metabolite was resistant to hydrolysis with β-glucuronidase; however it was only detected in urine up to four days after administration. The three glucuronide metabolites with the highest retrospectivity were identified by chemical synthesis or mass spectrometric data, and although they were previously reported, this is the first time that analytical data of the intact phase II metabolites are presented for some of them. The LC-MS/MS strategies applied have demonstrated to be useful for detecting glucuronoconjugated metabolites of MTD, including glucuronides resistant to enzymatic hydrolysis which cannot be detected by conventional approaches. Copyright © 2016 John Wiley & Sons, Ltd.

  20. LC-MS/MS Based Proteomic Analysis and Functional Inference of Hypothetical Proteins in Desulfovibrio Vulgaris

    SciTech Connect

    Zhang, Weiwen; Culley, David E.; Gritsenko, Marina A.; Moore, Ronald J.; Nie, Lei; Scholten, Johannes C.; Petritis, Konstantinos; Strittmatter, Eric F.; Camp, David G.; Smith, Richard D.; Brockman, Fred J.

    2006-11-03

    Direct liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to examine the proteins extracted from Desulfovibrio vulgaris cells. While our previous study provided a proteomic overview of the cellular metabolism based on proteins with known functions (Zhang et al., 2006a, Proteomics, 6: 4286-4299), this study describes the global detection and functional inference for hypothetical D. vulgaris proteins. Across six growth conditions, 15,841 tryptic peptides were identified with high confidence. Using a criterion of peptide identification from at least two out of three independent LC-MS/MS analyses per protein, 176 open reading frames (ORFs) originally annotated as hypothetical proteins were found to encode expressed proteins. These proteins ranged from 6.0 to 153 kDa, and had calculated pI values ranging from 3.7 to 11.5. Based on homology search results (with E value <= 0.01 as a cutoff), 159 proteins were defined as conserved hypothetical proteins, and 17 proteins were unique to the D. vulgaris genome. Functional inference of the conserved hypothetical proteins was performed by a combination of several non-homology based methods: genomic context analysis, phylogenomic profiling, and analysis of a combination of experimental information including peptide detection in cells grown under specific culture conditions and cellular location of the proteins. Using this approach we were able to assign possible functions to 27 conserved hypothetical proteins. This study demonstrated that a combination of proteomics and bioinformatics methodologies can provide verification for the authenticity of hypothetical proteins and improve annotation for the D. vulgaris genome.

  1. Determination of Dextromethorphan in Oral Fluid by LC-MS-MS.

    PubMed

    Amaratunga, Piyadarsha; Clothier, Morgan; Lorenz Lemberg, Bridget; Lemberg, Dave

    2016-06-01

    Dextromethorphan (DXM) is an antitussive drug found in commonly used nonprescription cold and cough medications. At low doses, DXM is a safe drug that does not produce adverse reactions. However, abuse of DXM has been reported among adolescents and young adults using the drug at higher doses. DXM is not a scheduled drug in the USA, and the primary reason for its abuse is the ease of availability. DXM is available to purchase in the form of over-the-counter cough medications, such as Robitussin(®) and Coricidin(®), or it can be purchased over the Internet in the form of a powder. In this research work, we developed an LC-MS-MS method that can quantify DXM and dextrorphan (DXO) in oral fluid in a high-throughput toxicology laboratory setting. The developed method was validated according to the Scientific Working Group for Forensic Toxicology guidelines. The linear dynamic range was 5-100 ng/mL with a lowest limit of quantitation (LLOQ) of 5.0 ng/mL for DXM and DXO. Overall, the results of the accuracy and the precision values were within the acceptance criteria for both drugs. In addition, selectivity, matrix effect and recovery were calculated for the LC-MS-MS method. Authentic samples (n = 59) were tested to evaluate the applicability of the method. Thirty samples were found to be positive for DXM and DXO and two samples were found to be positive for DXM only. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  2. Rapid Multi-Residue Analysis of Pesticides in Pulses by LC-MS/MS.

    PubMed

    Iwakoshi, Keiko; Otsuka, Kenji; Tamura, Yasuhiro; Tomizawa, Sanae; Masubuchi, Tamako; Yamaki, Yumiko; Nakagawa, Yukiko; Masuda, Ryoko; Suto, Shota; Kokaji, Yoshie; Shindo, Tetsuya; Takano, Ichiro

    2016-01-01

    Rapid multi-residue analysis of pesticides in pulses was developed using LC-MS/MS. Pesticide residues in 5 g of homogenized pulses were extracted with 30 mL of acetonitrile and salted out with 4 g of anhydrous magnesium sulfate and 2 g of sodium chloride in the presence of citrate buffer in a disposable tube. The resulting residues were extracted with 30 mL of acetonitrile, and co-extractives were removed on a handmade four-layer column, consisting of a layer of Z-Sep/C18 (20 mg/50 mg) dry particles on top of a three-layer, custom-made (pre-packed) column (lower bed: 60 mg of PSA, middle bed: 30 mg of GC, and top bed: 60 mg of C18) packed in a 10 mm internal diameter polypropylene column (3 mL). The developed method showed good recoveries of pesticides in soybean, lentil, white kidney bean and garbanzo. According to the method validation guideline of the Ministry of Health, Labour and Welfare of Japan, recovery tests were conducted in soybeans fortified with 107 kinds of pesticides at the levels of 0.01 and 0.1 μg/g, respectively. At each concentration 2 samples were extracted on 5 separate days. Pesticides in the test solution were determined by LC-MS/MS using scheduled MRM. As regards the trueness of this method for 107 pesticides in soybeans, 97 pesticides were in the range of 70-120% with satisfactory repeatability and within-run reproducibility. This new method is expected to be applicable for routine examination of pesticide residues in soybeans.

  3. Therapeutic monitoring of amphotericin B in Saudi ICU patients using UPLC MS/MS assay.

    PubMed

    Al-Quadeib, Bushra T; Radwan, Mahasen A; Siller, Lidija; Mutch, Elaine; Horrocks, Ben; Wright, Matthew; Alshaer, Abdulaziz

    2014-12-01

    Amphotericin B (AmB) is the first-line agent for the treatment of life-threatening invasive fungal infections. The aim of this study was to monitor AmB in critically ill Saudi patients in ICU after i.v. administration of 0.68 ± 0.1 mg/kg/day Fungizone®. A selective, sensitive and precise UPLC MS/MS method was developed to measure AmB concentrations in these patients. Seven ICU patients with creatinine clearance (ClCr) >40 mL/min were included. AmB levels were analyzed using a Waters Aquity UPLC MS/MS system, a BEH Shield RP18 column and detection via electrospray ionization source with positive ionization mode. The precision and accuracy of the developed UPLC method in the concentration range of 200-4000 ng/mL show no significant difference among inter- and-intra-day analysis (p > 0.05). Linearity was observed over the investigated range with correlation coefficient, r > 0.995 (n = 6/day). The pharmacokinetics of AmB in these patients, at steady state, showed a high terminal half-life of 124.6 ± 73.4 h, with a highest concentration of 513.9 ± 281.1 ng/mL, a lowest concentration 316.4 ± 129.0 ng/mL and a mean clearance 91.1 ± 39.2 mL/h/kg. The pharmacokinetics of AmB in critically ill Saudi patients in ICU was studied using a fully validated assay. A weak correlation (r = -0.22) of AmB Cl with ClCr was obtained, which suggests the need for further investigation in a larger population.

  4. HPLC-MS/MS method for bioavailability study of bruceines D & E in rat plasma.

    PubMed

    Man, Farahdina; Choo, Chee-Yan

    2017-09-15

    Bruceines D and E are quassinoids from seeds of Brucea javanica (L.) Merr. exhibiting hypoglycemia effect. The crude drug is used as a traditional medicine by diabetes patients. The aim of this study is to understand the bioavailability and pharmacokinetics of both the bruceines D & E. A rapid and sensitive HPLC-MS/MS method was developed and validated for the quantification of both quassinoids, bruceines D & E in rat plasma. Both the bruceines D & E were separated with the Zorbax SBC-18 column with gradient elution and mobile phase system of acetonitrile and deionized water with 0.1% formic acid at a flow rate of 0.5mL/min. Analytes were detected in multiple reaction monitoring (MRM) mode with electrospray positive ionization. The quassinoids, namely bruceines D & E were detected with transitions of m/z 411.2→393.2 and m/z 395.2→377.2, respectively. Another quassinoid, eurycomanone was used as the internal standard with transition of m/z 409.2→391.2. The method was validated and conformed to the regulatory requirements. The validated method was applied to pharmacokinetic and bioavailability studies in rats. The pharmacokinetic study indicated both bruceine D and E were rapidly absorbed into the circulation system and reached its peak concentration at 0.54±0.34h and 0.66±0.30h, respectively. Bruceine E was eliminated slower than Bruceine D with t1/2 value almost increased two-fold compared to Bruceine D. In conclusion, a rapid, selective and sensitive HPLC-MS/MS method was developed for the simultaneous determination of both the bruceines D and E in rat plasma. Both bruceines D and E displayed poor oral bioavailability. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. STS-47 MS Davis and MS/PLC Lee examine SLJ Rack 10 during KSC inspection

    NASA Technical Reports Server (NTRS)

    1992-01-01

    STS-47 Endeavour, Orbiter Vehicle (OV) 105, Mission Specialist N. Jan Davis and MS and Payload Commander (PLC) Mark C. Lee, wearing clean suits, examine NASDA Material Sciences control panel on Spacelab Japan (SLJ) Rack 10 during an inspection of the SLJ module. The module is currently undergoing preflight processing in a high bay of the Kennedy Space Center's (KSC's) Orbiter Processing Facility (OPF). View provided by KSC with alternate KSC number KSC-92PC-1644.

  6. Robust HPLC-MS/MS method for levofloxacin and ciprofloxacin determination in human prostate tissue.

    PubMed

    Szerkus, O; Jacyna, J; Gibas, A; Sieczkowski, M; Siluk, D; Matuszewski, M; Kaliszan, R; Markuszewski, M J

    2017-01-05

    Fluoroquinolones are the drugs of choice in the prevention of bacterial infections after transrectal ultrasound guided prostate biopsy. In order to improve assessment of antibacterial efficacy in the target tissue a simple, selective, rapid and robust HPLC-ESI-MS/MS method for the determination of levofloxacin and ciprofloxacin concentrations in human prostate bioptates was developed and validated. Preparation procedure for prostate samples (10mg) was carried out using homogenization and filtration steps. Analyses were performed within 3.5min using RP C18 column in the isocratic elution mode with mobile phase composed of a mixture of 0.1% formic acid aqueous solution and 0.1% formic acid methanol solution (v/v; 79:21). The method was linear between 0.3μg/g and 15μg/g for levofloxacin and ciprofloxacin with coefficient of correlation (r) ≥0.999. The limit of detection and the limit of quantification for levofloxacin were 0.06μg/g and 0.2μg/g and for ciprofloxacin were 0.04μg/g and 0.13μg/g, respectively. Average concentrations (±SD) of levofloxacin and ciprofloxacin obtained from patients tissue were 5.4±2.2μg/g and 3.9±1.5μg/g, respectively. Additionally, during validation procedure a novel, experimental design approach was applied for the robustness study. For evaluation of analytical method robustness, Plackett-Burman design was employed and for sample preparation method robustness Fractional Factorial design was used. The developed and validated method was successfully applied to examine prostate tissue samples obtained from patients enrolled into a clinical study. Up to now, there has been no other HPLC-ESI-MS/MS method reported for the simultaneous determination of levofloxacin and ciprofloxacin in human prostatic tissue. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Analysis of free, mono- and diacetylated polyamines from human urine by LC-MS/MS.

    PubMed

    Häkkinen, Merja R; Roine, Antti; Auriola, Seppo; Tuokko, Antti; Veskimäe, Erik; Keinänen, Tuomo A; Lehtimäki, Terho; Oksala, Niku; Vepsäläinen, Jouko

    2013-12-15

    Polyamines are promising biochemical markers of cancer and many other pathophysiological conditions, and thus their concentrations in biological fluids are a matter of interest. However, since the concentrations of these compounds are low, their quantitation is typically based on methods requiring laborious sample preparation. Here we developed and validated an LC-MS/MS method to analyze simultaneously free (DAP, PUT, CAD, SPD, SPM) monoacetylated (AcPUT, AcCAD, N(1)AcSPD, N(8)AcSPD, N(1)AcSPM) and diacetylated (DiAcPUT, DiAcCAD, DiAcSPD, DiAcSPM) polyamines from human urine without the need for derivatization. Deuterium labeled polyamines were the internal standards for each analyte. Diluted urine samples spiked with internal standards were filtered through a strong anion exchange resin prior to LC-MS/MS analysis. The chromatographic separation of 14 polyamines was achieved in 12min on C18 column with 0.1% HFBA (v/v) as the ion-pairing agent and a water-acetonitrile gradient. Ionization was performed with positive electrospray ionization (ESI) and detection was with a triple quadrupole mass spectrometer with selected reaction monitoring. Calibration curves ranged from up to 5 to 10,000nM. The accuracy and precision of the method were determined using urine based quality control samples, and matrix effects were examined by using standard addition methods. This novel method is suitable for elucidating differences in urinary polyamine excretion in cancer patients and healthy humans.

  8. LC-MS/MS Method for the Simultaneous Determination of Free Urinary Steroids.

    PubMed

    Allende, Fidel; Solari, Sandra; Campino, Carmen; Carvajal, Cristian A; Lagos, Carlos F; Vecchiola, Andrea; Valdivia, Carolina; Baudrand, René; Owen, Gareth I; Fardella, Carlos E

    2014-01-01

    Cortisol homeostasis is implicated in hypertension and metabolic syndrome. Two enzymes modulate cortisol availability; 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) preferentially converts inactive cortisone to cortisol, whereas 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2) converts cortisol to cortisone. In contrast, 5α and 5β reductases inactivate cortisol by conversion to its tetrahydrometabolites: tetrahydrocortisol, allo-tetrahydrocortisol and tetrahydrocortisone. A subtle local increase in cortisol can be detected by measuring 24-h urine metabolites, LC-MS/MS being the reference method. The 11β-HSD2 activity is assessed based on the cortisol/cortisone ratio, and the 11β-HSD1 activity on the (tetrahydrocortisol + allo-tetrahydrocortisol)/tetrahydrocortisone ratio. To better understand hypertension and/or metabolic syndrome pathogenesis a method for simultaneous determination of cortisol, cortisone, tetrahydrocortisol, allo-tetrahydrocortisol and tetrahydrocortisone was developed and validated in an LC coupled with the new detector AB Sciex QTrap(®) 4500 tandem mass spectrometer. The steroids were extracted from 1 mL urine, using cortisol-D4 as internal standard. The quantification range was 0.1-120 ng/mL for cortisol and cortisone, and 1-120 ng/mL for tetrahydrometabolites, with >89 % recovery for all analytes. The coefficient of variation and accuracy was <10 %, and 85-105 %, respectively. Our LC-MS/MS method is accurate and reproducible in accordance with Food and Drug Administration guidelines, showing good sensitivity and recovery. This method allows the assessment of 11β-HSD2 and 11β-HSD1 activities in a single analytical run providing an innovative tool to explain etiology of misclassified essential hypertension and/or metabolic syndrome.

  9. QC Metrics from CPTAC Raw LC-MS/MS Data Interpreted through Multivariate Statistics

    PubMed Central

    2015-01-01

    Shotgun proteomics experiments integrate a complex sequence of processes, any of which can introduce variability. Quality metrics computed from LC-MS/MS data have relied upon identifying MS/MS scans, but a new mode for the QuaMeter software produces metrics that are independent of identifications. Rather than evaluating each metric independently, we have created a robust multivariate statistical toolkit that accommodates the correlation structure of these metrics and allows for hierarchical relationships among data sets. The framework enables visualization and structural assessment of variability. Study 1 for the Clinical Proteomics Technology Assessment for Cancer (CPTAC), which analyzed three replicates of two common samples at each of two time points among 23 mass spectrometers in nine laboratories, provided the data to demonstrate this framework, and CPTAC Study 5 provided data from complex lysates under Standard Operating Procedures (SOPs) to complement these findings. Identification-independent quality metrics enabled the differentiation of sites and run-times through robust principal components analysis and subsequent factor analysis. Dissimilarity metrics revealed outliers in performance, and a nested ANOVA model revealed the extent to which all metrics or individual metrics were impacted by mass spectrometer and run time. Study 5 data revealed that even when SOPs have been applied, instrument-dependent variability remains prominent, although it may be reduced, while within-site variability is reduced significantly. Finally, identification-independent quality metrics were shown to be predictive of identification sensitivity in these data sets. QuaMeter and the associated multivariate framework are available from http://fenchurch.mc.vanderbilt.edu and http://homepages.uc.edu/~wang2x7/, respectively. PMID:24494671

  10. Simultaneous Determination of 11 Illicit Phenethylamines in Hair by LC-MS-MS: In Vivo Application.

    PubMed

    Nieddu, Maria; Burrai, Lucia; Demontis, Maria Piera; Varoni, Maria Vittoria; Baralla, Elena; Trignano, Claudia; Boatto, Gianpiero

    2015-09-01

    Existing phenethylamines are a class of synthetic compounds that differ from each other only in small changes to a largely conserved chemical structure. The recreational and illicit use of phenethylamines is a widespread problem. A simple procedure for the simultaneous quantitative determination in hair of 11 phenethylamines that are officially recognized as illicit by Italian legislation (p-methoxyamphetamine; p-methoxymethamphetamine; 3,4,5-trimethoxyamphetamine; 2,5-dimethoxyamphetamine; 2,5-dimethoxy-4-methylamphetamine; 2,5-dimethoxy-4-ethylamphetamine; 2,5-dimethoxy-4-bromoamphetamine; 2,5-dimethoxy-4-bromophenethylamine; 2,5-dimethoxy-4-iodophenethylamine; 2,5-dimethoxy-4-ethylthiophenethylamine and 2,5-dimethoxy-4-n-propylthiophenethylamine) has been developed and validated. Extraction from the matrix was performed after incubation in methanolic HCl and filtered reconstituted extracts were injected into a liquid chromatography/tandem mass spectrometry system (LC-MS-MS) without any further purification steps. This validated LC-MS-MS method has been used to determine the in vivo accumulation/retention of the above target analytes in hair after repeat oral administration to rats. This experiment further permitted investigation of the effect of pigmentation on the uptake of these phenethylamines by hair and the effect of hair pigmentation. The developed method could potentially be used for forensic and toxicological purposes, in the detection and quantitation of these illicit substances in human hair in workplace drug testing; drug-facilitated crime investigation; driver re-licensing; determining drug abuse history and postmortem toxicology. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  11. Liquid- and gas-phase nitration of bovine serum albumin studied by LC-MS and LC-MS/MS using monolithic columns.

    PubMed

    Walcher, Wolfgang; Franze, Thomas; Weller, Michael G; Pöschl, Ulrich; Huber, Christian G

    2003-01-01

    Post-translational nitration of proteins was analyzed by capillary reversed-phase high-performance liquid chromatography (RP-HPLC) on-line interfaced to electrospray ionization mass spectrometry (ESI--MS) or tandem mass spectrometry (ESI--MS/MS). Both methods were compared using a tryptic digest of bovine serum albumin (BSA) and yielded sequence coverages of 95% and 33% with RP-HPLC--ESI--MS and RP-HPLC--ESI--MS/MS, respectively. At least 95% of the tyrosines were covered by the former method, whereas the latter method only detected less than 50% of the tyrosine-containing peptides. Upon liquid-phase nitration of BSA in aqueous solution using an excess of tetranitromethane, at least 16 of the 20 tyrosine residues were found to be nitrated. After exposure of solid BSA samples to gaseous nitrogen dioxide and ozone at atmospherically relevant concentration levels, only 3 nitrated peptides were detected. By use of such a model system, RP-HPLC--ESI--MS proved to be a rapid and highly efficient method for the comprehensive and quantitative detection of protein nitration.

  12. Characterization of a mixture of lobster digestive cysteine proteinases by ionspray mass spectrometry and tryptic mapping with LC--MS and LC--MS--MS

    NASA Astrophysics Data System (ADS)

    Thibault, P.; Pleasance, S.; Laycock, M. V.; Mackay, R. M.; Boyd, R. K.

    1991-12-01

    An inseparable mixture of two cysteine proteinases, isolated from the digestive tract of the American lobster, was investigated by ionspray mass spectrometry (ISP-MS), using a combination of infusion of intact proteins with on-line liquid chromatography--mass spectrometry (LC--MS) and LC--MS--MS analyses of tryptic digests. These data were interpreted by comparisons with predictions from results of molecular cloning of cysteine-proteinase-encoding messenger RNA sequences previously isolated from the lobster hepatopancreas. Investigations of the numbers of free thiol groups and of disulfide bonds were made by measuring the molecular weights of the alkylated proteins with and without prior reduction of disulfide bonds, and comparison with the corresponding data for the native proteins. Identification of tyrptic fragment peptides containing cysteine residues was facilitated by comparing LC--MS analyses of tryptic digests of denatured and of denatured and alkylated proteins, since such tryptic peptides are subject to shifts in both mass and retention time upon reduction and alkylation. Confirmation of amino acid sequences was obtained from fragment ion spectra of each tryptic peptide (alkylated or not) as it eluted from the column. Acquisition of such on-line LC--MS data was possible through use of the entire effluent from a standard 1 mm high performance liquid chromatography (HPLC) column by an IonsSpray® LC--MS interface (pneumatically assisted electrospray).

  13. DESI-MS/MS of Chemical Warfare Agents and Related Compounds

    NASA Astrophysics Data System (ADS)

    D'Agostino, Paul A.

    Solid phase microextraction (SPME) fibers were used to headspace ­sample chemical warfare agents and their hydrolysis products from glass vials and glass vials containing spiked media, including Dacron swabs, office carpet, paper and fabric. The interface of the Z-spray source was modified to permit safe introduction of the SPME fibers for desorption electrospray ionization mass spectrometric (DESI-MS) analysis. A "dip and shoot" method was also developed for the rapid sampling and DESI-MS analysis of chemical warfare agents and their hydrolysis products in liquid samples. Sampling was performed by simply dipping fused silica, stainless steel or SPME tips into the organic or aqueous samples. Replicate analyses were completed within several minutes under ambient conditions with no sample pre-treatment, resulting in a significant increase in sample throughput. The developed sample handling and analysis method was applied to the determination of chemical warfare agent content in samples containing unknown chemical and/or biological warfare agents. Ottawa sand was spiked with sulfur mustard, extracted with water and autoclaved to ensure sterility. Sulfur mustard was completely hydrolysed during the extraction/autoclave step and thiodiglycol was identified by DESI-MS, with analyses generally being completed within 1 min using the "dip and shoot" method.

  14. Identification and quantitation of new glutamic acid derivatives in soy sauce by UPLC/MS/MS.

    PubMed

    Frerot, Eric; Chen, Ting

    2013-10-01

    Glutamic acid is an abundant amino acid that lends a characteristic umami taste to foods. In fermented foods, glutamic acid can be found as a free amino acid formed by proteolysis or as a non-proteolytic derivative formed by microorganisms. The aim of the present study was to identify different structures of glutamic acid derivatives in a typical fermented protein-based food product, soy sauce. An acidic fraction was prepared with anion-exchange solid-phase extraction (SPE) and analyzed by UPLC/MS/MS and UPLC/TOF-MS. α-Glutamyl, γ-glutamyl, and pyroglutamyl dipeptides, as well as lactoyl amino acids, were identified in the acidic fraction of soy sauce. They were chemically synthesized for confirmation of their occurrence and quantified in the selected reaction monitoring (SRM) mode. Pyroglutamyl dipeptides accounted for 770 mg/kg of soy sauce, followed by lactoyl amino acids (135 mg/kg) and γ-glutamyl dipeptides (70 mg/kg). In addition, N-succinoylglutamic acid was identified for the first time in food as a minor compound in soy sauce (5 mg/kg). Copyright © 2013 Verlag Helvetica Chimica Acta AG, Zürich.

  15. OpenMS and TOPP: open source software for LC-MS data analysis.

    PubMed

    Bertsch, Andreas; Gröpl, Clemens; Reinert, Knut; Kohlbacher, Oliver

    2011-01-01

    Proteomics experiments based on state-of-the-art mass spectrometry produce vast amounts of data, which cannot be analyzed manually. Hence, software is needed which is able to analyze the data in an automated fashion. The need for robust and reusable software tools triggered the development of libraries implementing different algorithms for the various analysis steps. OpenMS is such a software library and provides a wealth of data structures and algorithms for the analysis of mass spectrometric data. For users unfamiliar with programming, TOPP ("The OpenMS Proteomics Pipeline") offers a wide range of already implemented tools sharing the same interface and designed for a specific analysis task each. TOPP thus makes the sophisticated algorithms of OpenMS accessible to nonprogrammers. The individual TOPP tools can be strung together into pipelines for analyzing mass spectrometry-based experiments starting from the raw output of the mass spectrometer. These analysis pipelines can be constructed using a graphical editor. Even complex analytical workflows can thus be analyzed with ease.

  16. LC-MS/MS determination of etravirine in rat plasma and its application in pharmacokinetic studies.

    PubMed

    Abobo, Cyril V; Wu, Lei; John, Jyothy; Joseph, Mathew K; Bates, Theodore R; Liang, Dong

    2010-11-15

    Etravirine is a non-nucleoside reverse transcriptase inhibitor (NNRTI) that is active against NNRT-resistant HIV-1. A simple, sensitive, and specific LC-MS/MS method was developed and validated for the analysis of etravirine in rat plasma using itraconazole as the internal standard. The analytes were extracted with ethyl acetate and chromatographed on a reverse-phase XTerra MS C₁₈ column. Elution was achieved with a mobile phase gradient varying the proportion of a 2 mM ammonium acetate aqueous solution containing 0.1% formic acid (solvent A) and a 0.1% formic acid in methanol solution (solvent B) at a flow rate of 300 μL/min. The analytes were monitored by tandem-mass spectrometry with positive electrospray ionization. The precursor/product transitions (m/z) in the positive ion mode were 435.9→163.6 and 706.7→392.6 for etravirine and the internal standard, respectively. Calibration curves were linear over the etravirine rat plasma concentration range of 1-100 ng/mL. The inter- and intra-day accuracy and precision were within ±10%. The assay has been successfully used for pharmacokinetic evaluation of etravirine using the rat as an animal model.

  17. LC-MS/MS determination of etravirine in rat plasma and its application in pharmacokinetic studies

    PubMed Central

    Abobo, Cyril; Wu, Lei; John, Jyothy; Joseph, Mathew K.; Bates, Theodore R.; Liang, Dong

    2010-01-01

    Etravirine is a non-nucleoside reverse transcriptase inhibitor (NNRTI) that is active against NNRT-resistant HIV-1. A simple, sensitive, and specific LC-MS/MS method was developed and validated for the analysis of etravirine in rat plasma using itraconazole as the internal standard. The analytes were extracted with ethyl acetate and chromatographed on a reverse-phase XTerra MS C18 column. Elution was achieved with a mobile phase gradient varying the proportion of a 2 mM ammonium acetate aqueous solution containing 0.1% formic acid (solvent A) and a 0.1% formic acid in methanol solution (solvent B) at a flow rate of 300 μL/min. The analytes were monitored by tandem-mass spectrometry with positive electrospray ionization. The precursor/product transitions (m/z) in the positive ion mode were 435.9→163.6 and 706.7→392.6 for etravirine and the internal standard, respectively. Calibration curves were linear over the etravirine rat plasma concentration range of 1 ng/mL to 100 ng/mL. The inter- and intra-day accuracy and precision were within ±10%. The assay has been successfully used for pharmacokinetic evaluation of etravirine using the rat as an animal model. PMID:20965798

  18. NEW APPLICATIONS OF LC-MS AND LC-MS2 TOWARD ...

    EPA Pesticide Factsheets

    Over the last 40 years, many organometallic compounds have been synthesized and used in a variety of consumer, agricultural, and industrial products. Including wastewater effluents, leaching, and direct land and water applications, there are many pathways that can disperse organometallics to the environment. Many of these compounds reach environmental compartments unchanged while others are transformed into chemical entities having different availability or toxicity to living organisms. Differences in the toxicological, biochemical, and environmental behavior of the various chemical forms of a trace-element often make the determination of the total element concentration inadequate. Considerable analytical progress in organometallic speciation has been made over the past decade, where hyphenated techniques involving highly efficient separation and sensitive detection have become the techniques of choice. Methods based on liquid chromatographic separation with mass spectrometric detection have revealed new organometallic compounds in environmental and biological matrices, contributing to a better understanding of biological effects and environmental fate of organometallics. This article surveys recent applications of liquid chromatography-mass spectrometry (LC-MS) and liquid chromatography-mass spectrometry-mass spectrometry (LC- MS-MS) for the determination of organometallic compounds in environmental matrices. The research focused on in the subtasks is the devel

  19. Quantification of flavonol glycosides in Camellia sinensis by MRM mode of UPLC-QQQ-MS/MS.

    PubMed

    Wu, Yahui; Jiang, Xiaolan; Zhang, Shuxiang; Dai, Xinlong; Liu, Yajun; Tan, Huarong; Gao, Liping; Xia, Tao

    2016-04-01

    Phenolic compounds are major components of tea flavour, in which catechins and flavonol glycosides play important roles in the astringent taste of tea infusion. However, the flavonol glycosides are difficult to quantify because of the large variety, as well as the inefficient seperation on chromatography. In this paper, a total of 15 flavonol glycosides in the tea plant (Camellia sinensis) were identified by the high performance liquid chromatography (HPLC) coupled to a time-of-flight mass spectrometer (TOF-MS), and a quantitative method was established based on multiple reaction monitoring (MRM) mode of ultra-high performance liquid chromatography (UPLC) coupled to a triple quadrupole mass spectrometer (QQQ-MS/MS). It provided the limit of detection and quantification to the order of picogram, which was more sensitive than the HPLC detection of the order of nanogram. The relative standard deviations of the intra- and inter-day variations in retention time and signal intensity (peak area) of six analytes were less than 0.26% and 4%, respectively. The flavonol glycosides of four tea cultivars were relatively quantified using the signal intensity (peak area) of product ion, in which six flavonol glycosides were quantified by the authentic standards. The results showed that the flavonol mono-, di- and tri-glycoside mostly accumulated in young leaves of the four tea cultivars. Notably, the myricetin 3-O-galactoside was the major component among the six flavonol glycosides detected.

  20. Simultaneous determination of 10 nucleosides and nucleobases in Antrodia camphorata using QTRAP LC-MS/MS.

    PubMed

    Chen, Fei; Zhang, Fengsu; Yang, Nianyun; Liu, Xunhong

    2014-09-01

    A liquid chromatography-triple-quadrupole linear ion trap mass spectrometry (LC-QTrap-MS) analysis has been developed for the identification and quantification of 10 nucleosides and nucleobases in extracts of Antrodia camphorata. The method was successfully used to qualitatively identify for six nucleosides namely, cytidine, uridine, inosine, guanosine, thymidine, adenosine and four nucleobases namely, uracil, guanine, xanthine, adenine in A. camphorata. Under optimized chromatographic conditions, good separation for 10 target compounds were obtained on an Agilent HC-C18(2) column (4.6 × 250 mm, 5 μm) eluted by a mobile phase of 5 mM ammonium acetate solution-methanol at a flow rate of 0.5 mL/min. Data acquisition was carried out in multiple reaction monitoring transition mode. Additional identification and confirmation of target compounds were performed using the enhanced product ion modus of the linear ion trap. It was the first report about simultaneous analysis of nucleosides and nucleobases in A. camphorata using this method. These results demonstrated that the QTRAP LC-MS/MS was a useful tool for quality evaluation of some medicinal plant products by using nucleosides and nucleobases as chemical markers. This method might also be utilized for the investigation of edible plant materials and agricultural products containing nucleosides and nucleobases. © The Author [2013]. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  1. The Navy’s M&S Standards Development Activities

    DTIC Science & Technology

    2010-01-01

    identify supporting protocols, techniques and processes. The purpose of this paper is to provide an overview of the Navy’s M&S standards development ...process and to identify new opportunities to develop and promote M&S Standards across the DoD and industry M&S communities. We will specifically...on the premise that no simulation can satisfy all uses and users. An individual simulation, or set of simulations, developed for one purpose can be

  2. 58. MISSISSIPPI, NOXUBEE CO. MACON MAHORNER'S BRIDGE, 1884, Ms. 14, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    58. MISSISSIPPI, NOXUBEE CO. MACON MAHORNER'S BRIDGE, 1884, Ms. 14, E 6.5 mi. to McLeod, 4.5 miles S on McLeod-Shuqualak road. Mahorner's bridge (1884). Lower panel point, west span. View is at right-angles to the bridge and from below deck level. show pin connection, floor beams, and stringers. Sarcone Photography, Columbus, Ms. Sep 1978. - Bridges of the Upper Tombigbee River Valley, Columbus, Lowndes County, MS

  3. A novel study of screening and confirmation of modafinil, adrafinil and their metabolite modafinilic acid under EI-GC-MS and ESI-LC-MS-MS ionization

    PubMed Central

    Dubey, S.; Ahi, S.; Reddy, I. M.; Kaur, T.; Beotra, A.; Jain, S.

    2009-01-01

    Objective: Adrafinil and modafinil have received wide publicity and have become controversial in the sporting world when several athletes were discovered allegedly using these drugs as doping agents. By acknowledging the facts, the World Anti-Doping Agency (WADA) banned these drugs in sports since 2004. The present study explores the possibility of differentiating adrafinil and modafinil and their major metabolites under electron impact ionization in gas chromatograph–mass spectrometer (GC-MSD) and electrospray ionization in liquid chromatograph–mass spectrometer (LC-MS/MS) by studying the fragmentation pattern of these drugs. Materials and Methods: Adrafinil, modafinil and their major metabolite, modafinilic acid were analyzed on EI-GC-MSD and ESI-LC-MS/MS using various individual parameters on both the instruments. The analytical technique and equipment used in the analysis were an Agilent 6890N GC with 5973 mass selective detector for the GC-MSD analysis and an Agilent 1100 HPLC with API-3200 Triple quadrupole mass spectrometer for the LC-MS/MS analysis. Validation of both methods was performed using six replicates at different concentrations. Result and Discussion: The results show that adrafinil, modafinil and their major metabolite modafinilic acid could be detected as a single artifact without differentiation under EI-GC-MSD analysis. However, all drugs could be detected and differentiated under ESI-LCMS/MS analysis without any artifaction. The GC-MSD analysis gives a single artifact for both the drugs without differentiation and thus can be used as a marker for screening purposes. Further, the Multiple Reaction Monitoring (MRM) method developed under LC-MS/MS is fit for the purpose for confirmation of suspicious samples in routine sports testing and in forensic and clinical analysis. PMID:20407560

  4. A novel study of screening and confirmation of modafinil, adrafinil and their metabolite modafinilic acid under EI-GC-MS and ESI-LC-MS-MS ionization.

    PubMed

    Dubey, S; Ahi, S; Reddy, I M; Kaur, T; Beotra, A; Jain, S

    2009-12-01

    Adrafinil and modafinil have received wide publicity and have become controversial in the sporting world when several athletes were discovered allegedly using these drugs as doping agents. By acknowledging the facts, the World Anti-Doping Agency (WADA) banned these drugs in sports since 2004. The present study explores the possibility of differentiating adrafinil and modafinil and their major metabolites under electron impact ionization in gas chromatograph-mass spectrometer (GC-MSD) and electrospray ionization in liquid chromatograph-mass spectrometer (LC-MS/MS) by studying the fragmentation pattern of these drugs. Adrafinil, modafinil and their major metabolite, modafinilic acid were analyzed on EI-GC-MSD and ESI-LC-MS/MS using various individual parameters on both the instruments. The analytical technique and equipment used in the analysis were an Agilent 6890N GC with 5973 mass selective detector for the GC-MSD analysis and an Agilent 1100 HPLC with API-3200 Triple quadrupole mass spectrometer for the LC-MS/MS analysis. Validation of both methods was performed using six replicates at different concentrations. The results show that adrafinil, modafinil and their major metabolite modafinilic acid could be detected as a single artifact without differentiation under EI-GC-MSD analysis. However, all drugs could be detected and differentiated under ESI-LCMS/MS analysis without any artifaction. The GC-MSD analysis gives a single artifact for both the drugs without differentiation and thus can be used as a marker for screening purposes. Further, the Multiple Reaction Monitoring (MRM) method developed under LC-MS/MS is fit for the purpose for confirmation of suspicious samples in routine sports testing and in forensic and clinical analysis.

  5. Diagnosing Depression in MS in the Face of Overlapping Symptoms.

    PubMed

    Patten, Sb

    2010-01-01

    Depression is an important problem in multiple sclerosis (MS), but the diagnosis is challenging since symptoms of depression overlap with those of MS. In the past, the main strategy has been to remove physical symptoms from scales assessing depressive symptoms in MS, but these attempts have not been successful. Depression and overlapping MS symptoms may actually share pathophysiological mechanisms, so the strategy of attempting to exclude such symptoms may be fundamentally flawed. Current diagnostic criteria provide a pragmatic solution, but it may be possible to develop improved definitions.

  6. International Pediatric MS Study Group Global Members Symposium report.

    PubMed

    Wassmer, Evangeline; Chitnis, Tanuja; Pohl, Daniela; Amato, Maria Pia; Banwell, Brenda; Ghezzi, Angelo; Hintzen, Rogier Q; Krupp, Lauren B; Makhani, Naila; Rostásy, Kevin; Tardieu, Marc; Tenembaum, Silvia; Waldman, Amy; Waubant, Emmanuelle; Kornberg, Andrew J

    2016-08-30

    The International Pediatric Multiple Sclerosis Study Group held its inaugural educational program, "The World of Pediatric MS: A Global Update," in September 2014 to discuss advances and challenges in the diagnosis and management of pediatric multiple sclerosis (MS) and other neuroinflammatory CNS disorders. Highlights included a discussion on the revised diagnostic criteria, which enable the differentiation of MS, acute disseminated encephalomyelitis, neuromyelitis optica, and other neuroinflammatory disorders. While these criteria currently identify clinical and MRI features for a particular diagnosis, advances in biomarkers may prove to be useful in the future. An update was also provided on environmental factors associated with pediatric MS risk and possibly outcomes, notably vitamin D deficiency. However, optimal vitamin D intake and its role in altering MS course in children have yet to be established. Regarding MS outcomes, our understanding of the cognitive consequences of early-onset MS has grown. However, further work is needed to define the course of cognitive function and its long-term outcome in diverse patient samples and to develop strategies for effective cognitive rehabilitation specifically tailored to children and adolescents. Finally, treatment strategies were discussed, including a need to consider additional drug treatment options and paradigms (escalation vs induction), although treatment should be tailored to the individual child. Of critical importance, clinical trials of newer MS agents in children are required. Although our understanding of childhood MS has improved, further research is needed to have a positive impact for children and their families.

  7. Preprocessing and Analysis of LC-MS-Based Proteomic Data

    PubMed Central

    Tsai, Tsung-Heng; Wang, Minkun; Ressom, Habtom W.

    2016-01-01

    Liquid chromatography coupled with mass spectrometry (LC-MS) has been widely used for profiling protein expression levels. This chapter is focused on LC-MS data preprocessing, which is a crucial step in the analysis of LC-MS based proteomics. We provide a high-level overview, highlight associated challenges, and present a step-by-step example for analysis of data from LC-MS based untargeted proteomic study. Furthermore, key procedures and relevant issues with the subsequent analysis by multiple reaction monitoring (MRM) are discussed. PMID:26519169

  8. Ethyl Esterification for MALDI-MS Analysis of Protein Glycosylation.

    PubMed

    Reiding, Karli R; Lonardi, Emanuela; Hipgrave Ederveen, Agnes L; Wuhrer, Manfred

    2016-01-01

    Ethyl esterification is a technique for the chemical modification of sialylated glycans, leading to enhanced stability when performing matrix-assisted laser desorption/ionization (MALDI)-mass spectrometry (MS), as well as allowing the efficient detection of both sialylated and non-sialylated glycans in positive ion mode. In addition, the method shows specific reaction products for α2,3- and α2,6-linked sialic acids, leading to an MS distinguishable mass difference. Here, we describe the ethyl esterification protocol for 96 glycan samples, including enzymatic N-glycan release, the aforementioned ethyl esterification, glycan enrichment, MALDI target preparation, and the MS(/MS) measurement.

  9. A new type of GC-MS with advanced capabilities

    NASA Astrophysics Data System (ADS)

    Fialkov, Alexander B.; Steiner, Urs; Jones, Larry; Amirav, Aviv

    2006-03-01

    We have combined the benefits of supersonic molecular beam interface and its related fly-through electron ionization (EI) ion source with the advanced features of the Varian 1200L gas chromatography-mass spectrometry (GC-MS) and mass spectrometry-mass spectrometry (MS-MS), resulting in a new and powerful GC-MS platform with record setting performance. Electron ionization of vibrationally cold molecules in the supersonic molecular beams (SMB) (cold EI) provided mass spectra with enhanced molecular ion, yet with good library search results and superior identification probabilities. We found that high GC column flow rates lower the elution temperature for any given compounds. This allows much larger molecules to elute at the maximum temperature of standard columns. We analyzed a mixture of heavy linear chain hydrocarbons all the way to C84H170 with a molecular weight of 1179.3 amu, using a 4 m 0.25 mm i.d. column and 32 ml/min He flow rate. Furthermore, we obtained a dominant molecular ion to all these compounds. The lower elution temperatures also greatly enhance the ability to analyze very thermally labile compounds such as carbamate pesticides. The experimental 1200 system is capable of triple quadrupole based MS-MS. We found that MS-MS on the molecular ion is much more effective than on fragment ions, and thus, the enhancement of the molecular ion directly improves the MS-MS sensitivity. Fast GC-MS analysis was also explored, based on very high column flow rate for fast splitless injections without affecting the sensitivity, and on the high system selectivity due to the combination of enhanced molecular ion and MS-MS. We demonstrate a few seconds long GC-MS-MS analysis of diazinon, spiked at 10 ng/g in a mixed fruit and vegetable extract. The feature of enhanced molecular ion provides significant enhancement in the detection sensitivity via SIM and RSIM on the molecular ion. While octafluoronaphthalene (OFN) detection limit of below 1 fg in SIM mode is shown, the

  10. Reproductive decision making after the diagnosis of multiple sclerosis (MS).

    PubMed

    Alwan, S; Yee, I M; Dybalski, M; Guimond, C; Dwosh, E; Greenwood, T M; Butler, R; Sadovnick, A D

    2013-03-01

    This study aimed to determine reproductive practices and attitudes of North Americans diagnosed with multiple sclerosis (MS) and the reasons for their reproductive decision making. A self-administered questionnaire on reproductive practices was mailed to 13,312 registrants of the North American Research Committee on Multiple Sclerosis (NARCOMS) database who met inclusion criteria for the study. Completed questionnaires were then returned to the authors in an anonymous format for analysis. Among 5949 participants, the majority of respondents (79.1%) did not become pregnant following diagnosis of MS. Of these, 34.5% cited MS-related reasons for this decision. The most common MS-related reasons were symptoms interfering with parenting (71.2%), followed by concerns of burdening partner (50.7%) and of children inheriting MS (34.7%). The most common reason unrelated to MS for not having children was that they already have a "completed family" (55.6%). Of the 20.9% of participants who decided to become pregnant (or father a pregnancy) following a diagnosis of MS, 49.5% had two or more pregnancies. This study indicates that an MS diagnosis does not completely deter the consideration of childbearing in MS patients of both genders.

  11. EPA LABORATORIES IMPLEMENT EMS PROGRAM

    EPA Science Inventory

    This paper highlights the breadth and magnitude of carrying out an effective Environmental Management System (EMS) program at the U.S. EPA's research and development laboratories. Federal research laboratories have unique operating challenges compared to more centralized industr...

  12. Quantitative analysis of lipids: a higher-throughput LC–MS/MS-based method and its comparison to ELISA

    PubMed Central

    Gandhi, Adarsh S; Budac, David; Khayrullina, Tanzilya; Staal, Roland; Chandrasena, Gamini

    2017-01-01

    Aim: Lipids such as prostaglandins, leukotrienes and thromboxanes are released as a result of an inflammatory episode in pain (central and peripheral). Methodology & results: To measure these lipids as potential mechanistic biomarkers in neuropathic pain models, we developed a higher-throughput LC–MS/MS-based method with simultaneous detection of PGE2, PGD2, PGF2α, LTB4, TXB2 and 2-arachidonoyl glycerol in brain and spinal cord tissues. We also demonstrate that the LC–MS/MS method was more sensitive and specific in differentiating PGE2 levels in CNS tissues compared with ELISA. Conclusion: The ability to modify the LC–MS/MS method to accommodate numerous other lipids in one analysis, demonstrates that the presented method offers a cost–effective and more sensitive alternative to ELISA method useful in drug discovery settings. PMID:28344822

  13. Evaluation of GC-ion trap-MS/MS methodology for monitoring PCDD/Fs in infant formulas.

    PubMed

    Lorán, Susana; Bayarri, Susana; Conchello, Pilar; Herrera, Antonio

    2007-03-01

    The application of high resolution gas chromatography in combination with low resolution mass spectrometry with electron ionization and MS/MS detection (HRGC-MS/MS) is tested for its use in the analysis of PCDD/Fs in infant formulas. Development of the analytical method was based upon EPA directrices and international recommendations. Calibration linearity was tested and average relative response for any native and labelled compound over the five-point calibration range below 14% was found. The precision and accuracy of the proposed analytical procedure are also presented. Results obtained are in agreement with EPA criteria. The method is applied to the analysis of a number of initial and follow-on milk based infant formulas. In general, HRGC-MS/MS constitutes an interesting method for the analysis of dioxins in such matrices.

  14. Quantification of Dehydroepiandrosterone, 11-Deoxycortisol, 17-Hydroxyprogesterone, and Testosterone by Liquid Chromatography-Tandem Mass Spectrometry (LC/MS/MS).

    PubMed

    Munar, Ada; Frazee, Clint; Garg, Uttam

    2016-01-01

    Congenital adrenal hyperplasia (CAH) is a group of autosomal recessive disorders due to enzymatic defects in the biosynthetic pathway of cortisol and/or aldosterone. The analysis of cortisol, 17-hydroxyprogesterone (OHPG), dehydroepiandrosterone (DHEA), 11-deoxycortisol, and testosterone is generally performed in the diagnosis and/or follow-up of CAH. Cortisol is generally analyzed by immunoassays whereas other hormones are preferably assayed by liquid chromatography-tandem mass spectrometry (LC/MS/MS). A multiple reaction monitoring, positive mode atmospheric pressure chemical ionization, LC/MS/MS method is described for the simultaneous quantification of 17-hydroxyprogesterone, DHEA, 11-deoxycortisol, and testosterone. Stable-isotope labeled internal standards are added to serum samples and steroids are extracted by liquid-liquid extraction using methyl tert-butyl ether. The extract is evaporated under stream of nitrogen and the residue is reconstituted in methanol and analyzed by LC/MS/MS.

  15. LC-ESI-MS/MS identification of polar lipids of two thermophilic Anoxybacillus bacteria containing a unique lipid pattern.

    PubMed

    Rezanka, Tomáš; Kambourova, Margarita; Derekova, Anna; Kolouchová, Irena; Sigler, Karel

    2012-07-01

    Phospholipids and glycolipids from two recently described species belonging to the thermophilic genus Anoxybacillus were analyzed by liquid chromatography-electrospray tandem mass spectrometry (LC/ESI-MS/MS). Analysis of total lipids from the facultatively anaerobic A. bogrovensis on a HILIC (Hydrophilic Interaction LIquid Chromatography) column succeeded in separating diacyl- and plasmalogen phospholipids. The LC/ESI-MS/MS analysis of the strict aerobe A. rupiensis revealed the presence of different unique polar lipids, predominantly alanyl-, lysyl-, and glucosyl-phosphatidylglycerols and cardiolipins. Each of the classes of polar lipids was then analyzed by means of the ESI-MS/MS and more than 140 molecular species of six lipid classes from A. bogrovensis and nearly 200 molecular species of nine classes of polar lipids from A. rupiensis were identified. Five classes of unidentified polar lipids were detected in both strains. Plasmalogens were thus determined for the first time in a facultatively anaerobic bacterium, i.e. A. bogrovensis.

  16. MS/MS-Assisted Design of Sequence-Controlled Synthetic Polymers for Improved Reading of Encoded Information

    NASA Astrophysics Data System (ADS)

    Charles, Laurence; Cavallo, Gianni; Monnier, Valérie; Oswald, Laurence; Szweda, Roza; Lutz, Jean-François

    2016-12-01

    In order to improve their MS/MS sequencing, structure of sequence-controlled synthetic polymers can be optimized based on considerations regarding their fragmentation behavior in collision-induced dissociation conditions, as demonstrated here for two digitally encoded polymer families. In poly(triazole amide)s, the main dissociation route proceeded via cleavage of the amide bond in each monomer, hence allowing the chains to be safely sequenced. However, a competitive cleavage of an ether bond in a tri(ethylene glycol) spacer placed between each coding moiety complicated MS/MS spectra while not bringing new structural information. Changing the tri(ethylene glycol) spacer to an alkyl group of the same size allowed this unwanted fragmentation pathway to be avoided, hence greatly simplifying the MS/MS reading step for such undecyl-based poly(triazole amide)s. In poly(alkoxyamine phosphodiester)s, a single dissociation pathway was achieved with repeating units containing an alkoxyamine linkage, which, by very low dissociation energy, made any other chemical bonds MS/MS-silent. Structure of these polymers was further tailored to enhance the stability of those precursor ions with a negatively charged phosphate group per monomer in order to improve their MS/MS readability. Increasing the size of both the alkyl coding moiety and the nitroxide spacer allowed sufficient distance between phosphate groups for all of them to be deprotonated simultaneously. Because the charge state of product ions increased with their polymerization degree, MS/MS spectra typically exhibited groups of fragments at one or the other side of the precursor ion depending on the original α or ω end-group they contain, allowing sequence reconstruction in a straightforward manner.

  17. MS/MS-Assisted Design of Sequence-Controlled Synthetic Polymers for Improved Reading of Encoded Information

    NASA Astrophysics Data System (ADS)

    Charles, Laurence; Cavallo, Gianni; Monnier, Valérie; Oswald, Laurence; Szweda, Roza; Lutz, Jean-François

    2017-06-01

    In order to improve their MS/MS sequencing, structure of sequence-controlled synthetic polymers can be optimized based on considerations regarding their fragmentation behavior in collision-induced dissociation conditions, as demonstrated here for two digitally encoded polymer families. In poly(triazole amide)s, the main dissociation route proceeded via cleavage of the amide bond in each monomer, hence allowing the chains to be safely sequenced. However, a competitive cleavage of an ether bond in a tri(ethylene glycol) spacer placed between each coding moiety complicated MS/MS spectra while not bringing new structural information. Changing the tri(ethylene glycol) spacer to an alkyl group of the same size allowed this unwanted fragmentation pathway to be avoided, hence greatly simplifying the MS/MS reading step for such undecyl-based poly(triazole amide)s. In poly(alkoxyamine phosphodiester)s, a single dissociation pathway was achieved with repeating units containing an alkoxyamine linkage, which, by very low dissociation energy, made any other chemical bonds MS/MS-silent. Structure of these polymers was further tailored to enhance the stability of those precursor ions with a negatively charged phosphate group per monomer in order to improve their MS/MS readability. Increasing the size of both the alkyl coding moiety and the nitroxide spacer allowed sufficient distance between phosphate groups for all of them to be deprotonated simultaneously. Because the charge state of product ions increased with their polymerization degree, MS/MS spectra typically exhibited groups of fragments at one or the other side of the precursor ion depending on the original α or ω end-group they contain, allowing sequence reconstruction in a straightforward manner. [Figure not available: see fulltext.

  18. Time correlation between mononucleosis and initial symptoms of MS

    PubMed Central

    Endriz, John; Ho, Peggy P.

    2017-01-01

    Objective: To determine the average age of MS onset vs the age at which Epstein-Barr infection has previously occurred and stratify this analysis by sex and the blood level of Epstein-Barr nuclear antigen 1 (EBNA1) antibody. Methods: Using infectious mononucleosis (IM) as a temporal marker in data from the Swedish epidemiologic investigation of MS, 259 adult IM/MS cases were identified and then augmented to account for “missing” childhood data so that the average age of MS onset could be determined for cases binned by age of IM (as stratified by sex and EBNA1 titer level). Results: Mean age of IM vs mean age of MS reveals a positive time correlation for all IM ages (from ∼5 to ∼30 years), with IM-to-MS delay decreasing with increased age. When bifurcated by sex or EBNA1 blood titer levels, males and high-titer subpopulations show even stronger positive time correlation, while females and low-titer populations show negative time correlation in early childhood (long IM/MS delay). The correlation becomes positive in females beyond puberty. Conclusions: IM/MS time correlation implies causality if IM is time random. Alternative confounding models seem implausible, in light of constraints imposed by time-invariant delay observed here. Childhood infection with Epstein-Barr virus (EBV) in females and/or those genetically prone to low EBNA1 blood titers will develop MS slowly. Males and/or high EBNA1-prone develop MS more rapidly following IM infection at all ages. For all, postpubescent EBV infection is critical for the initiation and rapid development of MS. PMID:28271078

  19. Biodegradation of the (aliphatic + aromatic) fraction of Oural crude oil. Biomarker identification using GC/MS SIM and GC/MS/MS.

    PubMed

    Jacquot, F; Doumenq, P; Guiliano, M; Munoz, D; Guichard, J R; Mille, G

    1996-03-01

    A simplified fraction of the Oural crude oil (aliphatic and aromatic hydrocarbons) was incubated in the presence of an hydrocarbonoclastic bacterial community isolated from a marine sediment highly contaminated by petroleum residue. The biodegradation has been carried out under aerobic conditions for 5 weeks and followed by FTIR, UV synchronous luminescence and GC/FID. Disappearance of the n-alkanes (2nd week), an important attack of the isoprenoïd compounds (5th week) and preferential alteration of monomethylated polyaromatics were observed. Concerning the biomarkers, the bicyclic alkanes and pentacyclic terpanes have been comparatively elucidated using GC/MS data. The identification of C(26) to C(29) steranes has required a most selective method, namely GC/MS/MS. Many molecular ratios based on GC/MS abundances were calculated, which showed good stability. Consequently, they can be used to determine the origin of a petroleum even one altered by biodegradation.

  20. mzDB: a file format using multiple indexing strategies for the efficient analysis of large LC-MS/MS and SWATH-MS data sets.

    PubMed

    Bouyssié, David; Dubois, Marc; Nasso, Sara; Gonzalez de Peredo, Anne; Burlet-Schiltz, Odile; Aebersold, Ruedi; Monsarrat, Bernard

    2015-03-01

    The analysis and management of MS data, especially those generated by data independent MS acquisition, exemplified by SWATH-MS, pose significant challenges for proteomics bioinformatics. The large size and vast amount of information inherent to these data sets need to be properly structured to enable an efficient and straightforward extraction of the signals used to identify specific target peptides. Standard XML based formats are not well suited to large MS data files, for example, those generated by SWATH-MS, and compromise high-throughput data processing and storing. We developed mzDB, an efficient file format for large MS data sets. It relies on the SQLite software library and consists of a standardized and portable server-less single-file database. An optimized 3D indexing approach is adopted, where the LC-MS coordinates (retention time and m/z), along with the precursor m/z for SWATH-MS data, are used to query the database for data extraction. In comparison with XML formats, mzDB saves ∼25% of storage space and improves access times by a factor of twofold up to even 2000-fold, depending on the particular data access. Similarly, mzDB shows also slightly to significantly lower access times in comparison with other formats like mz5. Both C++ and Java implementations, converting raw or XML formats to mzDB and providing access methods, will be released under permissive license. mzDB can be easily accessed by the SQLite C library and its drivers for all major languages, and browsed with existing dedicated GUIs. The mzDB described here can boost existing mass spectrometry data analysis pipelines, offering unprecedented performance in terms of efficiency, portability, compactness, and flexibility. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.