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Sample records for em aquidauana ms

  1. 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

  2. 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. PMID:26718945

  3. 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. PMID:26062116

  4. 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. PMID:17071001

  5. Asymmetric cryo-EM reconstruction of phage MS2 reveals genome structure in situ.

    PubMed

    Koning, Roman I; Gomez-Blanco, Josue; Akopjana, Inara; Vargas, Javier; Kazaks, Andris; Tars, Kaspars; Carazo, José María; Koster, Abraham J

    2016-01-01

    In single-stranded ribonucleic acid (RNA) viruses, virus capsid assembly and genome packaging are intertwined processes. Using cryo-electron microscopy and single particle analysis we determined the asymmetric virion structure of bacteriophage MS2, which includes 178 copies of the coat protein, a single copy of the A-protein and the RNA genome. This reveals that in situ, the viral RNA genome can adopt a defined conformation. The RNA forms a branched network of stem-loops that almost all allocate near the capsid inner surface, while predominantly binding to coat protein dimers that are located in one-half of the capsid. This suggests that genomic RNA is highly involved in genome packaging and virion assembly. PMID:27561669

  6. Asymmetric cryo-EM reconstruction of phage MS2 reveals genome structure in situ

    PubMed Central

    Koning, Roman I; Gomez-Blanco, Josue; Akopjana, Inara; Vargas, Javier; Kazaks, Andris; Tars, Kaspars; Carazo, José María; Koster, Abraham J.

    2016-01-01

    In single-stranded ribonucleic acid (RNA) viruses, virus capsid assembly and genome packaging are intertwined processes. Using cryo-electron microscopy and single particle analysis we determined the asymmetric virion structure of bacteriophage MS2, which includes 178 copies of the coat protein, a single copy of the A-protein and the RNA genome. This reveals that in situ, the viral RNA genome can adopt a defined conformation. The RNA forms a branched network of stem-loops that almost all allocate near the capsid inner surface, while predominantly binding to coat protein dimers that are located in one-half of the capsid. This suggests that genomic RNA is highly involved in genome packaging and virion assembly. PMID:27561669

  7. Reproducibility of an Integrated Quantitation Method Coupling 2D GeLC-MS/MS with the emPAI for Comparative Proteomics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In 2D gel mapping, most protein spots consist of multiple proteins posing a significant challenge for the proper interpretation of gel-based comparative experiments. Previously we introduced an approach integrating 2-D difference gel electrophoresis and LC-MS/MS analysis with the exponentially modif...

  8. Pediatric MS

    MedlinePlus

    ... of the oral medications in the pediatric population. 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. 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.

  10. emGain: Determination of EM gain of CCD

    NASA Astrophysics Data System (ADS)

    Daigle, Olivier; Carignan, Claude; Blais-Ouellette, Sebastien

    2012-01-01

    The determination of the EM gain of the CCD is best done by fitting the histogram of many low-light frames. Typically, the dark+CIC noise of a 30ms frame itself is a sufficient amount of signal to determine accurately the EM gain with about 200 512x512 frames. The IDL code emGain takes as an input a cube of frames and fit the histogram of all the pixels with the EM stage output probability function. The function returns the EM gain of the frames as well as the read-out noise and the mean signal level of the frames.

  11. Nested data independent MS/MS acquisition.

    PubMed

    Kaufmann, Anton; Walker, Stephan

    2016-07-01

    Data independent acquisition (DIA) attempts to provide comprehensive MS/MS data while providing a cycle time that is capable of following the elution profile of chromatographic peaks. Currently available MS technology is not yet fully capable of fulfilling these expectations. This paper suggests a new multiplex-based approach to more closely achieve this objective. Customized scans have been programmed for a Q Orbitrap instrument. Multiple nonadjacent mass range segments are sequentially collected (cut out) by the quadrupole. These combined mass ranges undergo fragmentation, and the resulting product ions are analyzed as a whole by the Orbitrap analyzer. The systematical variation of the mass range segments (nested design) permits the mathematical assignment of the observed product ions within a narrow precursor mass range. The proposed approach allows the use of mass windows that are narrower than those in conventional DIA (SWATH). A unique aspect of the proposed approach is the fact that halving the mass window width requires the addition of only a single multiplexed scan. This is different from conventional DIA, which requires the number of mass windows to be doubled in order to achieve the same objective. This paper shows that for a given cycle time, the proposed nested DIA technique produces significantly less chimeric product ion spectra than conventional DIA. However, further improvements from the programming, and most likely the hardware side, are still required in order to achieve the aim of comprehensive MS/MS. Graphical Abstract Schematic of nested design. PMID:27188447

  12. Primary-Progressive MS (PPMS)

    MedlinePlus

    ... MS? Types of MS Primary progressive MS (PPMS) Primary progressive MS (PPMS) Share Smaller Text Larger Text Print In this article Overview PPMS is characterized by worsening neurologic function ( ...

  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. PMID:26489966

  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. MS/MS Automated Selected Ion Chromatograms

    Energy Science and Technology Software Center (ESTSC)

    2005-12-12

    This program can be used to read a LC-MS/MS data file from either a Finnigan ion trap mass spectrometer (.Raw file) or an Agilent Ion Trap mass spectrometer (.MGF and .CDF files) and create a selected ion chromatogram (SIC) for each of the parent ion masses chosen for fragmentation. The largest peak in each SIC is also identified, with reported statistics including peak elution time, height, area, and signal to noise ratio. It creates severalmore » output files, including a base peak intensity (BPI) chromatogram for the survey scan, a BPI for the fragmentation scans, an XML file containing the SIC data for each parent ion, and a "flat file" (ready for import into a database) containing summaries of the SIC data statistics.« less

  16. Living with Advanced MS

    MedlinePlus

    ... Read More Read More Resource Edward M. Dowd Personal Advocate Program The Edward M. Dowd Personal Advocate ... Informed About the Society Vision Careers Leadership Cultural Values Financials News Press Room MS Prevalence Charitable Ratings ...

  17. 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, ...

  18. 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

  19. IMS - MS Data Extractor

    Energy Science and Technology Software Center (ESTSC)

    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.

  20. Progressive-Relapsing MS (PRMS)

    MedlinePlus

    ... the disease process in MS and in MRI technology. Individuals who were previously diagnosed with progressive-relapsing MS would now be ... The National MS Society is Here to Help Need More Information? We ...

  1. 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.

  2. 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

  3. Secondary-Progressive MS (SPMS)

    MedlinePlus

    ... spite of the medication you are taking, the conversation with your MS care provider might be about ... SPMS is stable without activity or progression, the conversation with your MS care could focus on rehabilitation ...

  4. LC-MS and MS/MS in the analysis of recombinant proteins

    NASA Astrophysics Data System (ADS)

    Coulot, M.; Domon, B.; Grossenbacher, H.; Guenat, C.; Maerki, W.; Müller, D. R.; Richter, W. J.

    1993-03-01

    Applicability and performance of electrospray ionization mass spectrometry (ESIMS) is demonstrated for protein analysis. ESIMS is applied in conjunction with on-line HPLC (LC-ESlMS) and direct tandem mass spectrometry (positive and negative ion mode ESlMS/MS) to the structural characterization of a recombinant protein (r-hirudin variant 1) and a congener phosphorylated at threonine 45 (RP-1).

  5. MS-DIAL: Data Independent MS/MS Deconvolution for Comprehensive Metabolome Analysis

    PubMed Central

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

    2015-01-01

    Data-independent acquisition (DIA) in liquid chromatography tandem mass spectrometry (LC-MS/MS) provides more comprehensive untargeted acquisition of molecular data. Here we provide an open-source software pipeline, MS-DIAL, to demonstrate how DIA improves simultaneous identification and quantification of small molecules by mass spectral deconvolution. For reversed phase LC-MS/MS, our program with an enriched LipidBlast library identified total 1,023 lipid compounds from nine algal strains to highlight their chemotaxonomic relationships. PMID:25938372

  6. Internal calibrants allow high accuracy peptide matching between MALDI imaging MS and LC-MS/MS.

    PubMed

    Gustafsson, Johan O R; Eddes, James S; Meding, Stephan; Koudelka, Tomas; Oehler, Martin K; McColl, Shaun R; Hoffmann, Peter

    2012-08-30

    One of the important challenges for MALDI imaging mass spectrometry (MALDI-IMS) is the unambiguous identification of measured analytes. One way to do this is to match tryptic peptide MALDI-IMS m/z values with LC-MS/MS identified m/z values. Matching using current MALDI-TOF/TOF MS instruments is difficult due to the variability of in situ time-of-flight (TOF) m/z measurements. This variability is currently addressed using external calibration, which limits achievable mass accuracy for MALDI-IMS and makes it difficult to match these data to downstream LC-MS/MS results. To overcome this challenge, the work presented here details a method for internally calibrating data sets generated from tryptic peptide MALDI-IMS on formalin-fixed paraffin-embedded sections of ovarian cancer. By calibrating all spectra to internal peak features the m/z error for matches made between MALDI-IMS m/z values and LC-MS/MS identified peptide m/z values was significantly reduced. This improvement was confirmed by follow up matching of LC-MS/MS spectra to in situ MS/MS spectra from the same m/z peak features. The sum of the data presented here indicates that internal calibrants should be a standard component of tryptic peptide MALDI-IMS experiments. PMID:22634080

  7. Registration of MS-01RKN, MS-24RKN, MS-30RKN, MS-33RKN, MS-35RKN and MS-37RKN cotton germplasm lines with resistance to root-knot nematode

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mississippi Agricultural and Forestry Experiment Station, The Agricultural Research Service, United States Department of Agriculture, and Cotton Incorporated Cary, NC, announce the release of six germplasm lines of upland cotton, MS-01RKN, MS-24RKN, MS-30RKN, MS-33RKN, MS-35RKN, and MS-37RKN that ha...

  8. Hydrogen Rearrangement Rules: Computational MS/MS Fragmentation and Structure Elucidation Using MS-FINDER Software.

    PubMed

    Tsugawa, Hiroshi; Kind, Tobias; Nakabayashi, Ryo; Yukihira, Daichi; Tanaka, Wataru; Cajka, Tomas; Saito, Kazuki; Fiehn, Oliver; Arita, Masanori

    2016-08-16

    Compound identification from accurate mass MS/MS spectra is a bottleneck for untargeted metabolomics. In this study, we propose nine rules of hydrogen rearrangement (HR) during bond cleavages in low-energy collision-induced dissociation (CID). These rules are based on the classic even-electron rule and cover heteroatoms and multistage fragmentation. We evaluated our HR rules by the statistics of MassBank MS/MS spectra in addition to enthalpy calculations, yielding three levels of computational MS/MS annotation: "resolved" (regular HR behavior following HR rules), "semiresolved" (irregular HR behavior), and "formula-assigned" (lacking structure assignment). With this nomenclature, 78.4% of a total of 18506 MS/MS fragment ions in the MassBank database and 84.8% of a total of 36370 MS/MS fragment ions in the GNPS database were (semi-) resolved by predicted bond cleavages. We also introduce the MS-FINDER software for structure elucidation. Molecular formulas of precursor ions are determined from accurate mass, isotope ratio, and product ion information. All isomer structures of the predicted formula are retrieved from metabolome databases, and MS/MS fragmentations are predicted in silico. The structures are ranked by a combined weighting score considering bond dissociation energies, mass accuracies, fragment linkages, and, most importantly, nine HR rules. The program was validated by its ability to correctly calculate molecular formulas with 98.0% accuracy for 5063 MassBank MS/MS records and to yield the correct structural isomer with 82.1% accuracy within the top-3 candidates. In a test with 936 manually identified spectra from an untargeted HILIC-QTOF MS data set of human plasma, formulas were correctly predicted in 90.4% of the cases, and the correct isomer structure was retrieved at 80.4% probability within the top-3 candidates, including for compounds that were absent in mass spectral libraries. The MS-FINDER software is freely available at http

  9. 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. PMID:26808680

  10. 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."

  11. GeLC-MS/MS Analysis of Complex Protein Mixtures

    PubMed Central

    Dzieciatkowska, Monika; Hill, Ryan; Hansen, Kirk C.

    2015-01-01

    Discovery-based proteomics has found its place in nearly every facet of biological research. A key objective of this approach is to maximize sequence coverage for proteins across a wide concentration range. Fractionating samples at the protein level is one of the most common ways to circumvent challenges due to sample complexity and improve proteome coverage. Of the available methods, one-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by liquid chromatography-tandem mass spectrometry (GeLC-MS/MS) is a robust and reproducible method for qualitative and quantitative proteomic analysis. Here we describe a general GeLC-MS/MS protocol and include technical advice and outline caveats to increase the probability of a successful analysis. PMID:24791981

  12. 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. PMID:22767114

  13. Relapsing-Remitting MS (RRMS)

    MedlinePlus Videos and Cool Tools

    ... fibers themselves. During these inflammatory attacks, activated immune cells cause small, localized areas of damage which produce ... MRI) scans, and these lesions contain more inflammatory cells. People with primary progressive MS (PPMS) tend to ...

  14. ExMS: data analysis for HX-MS experiments.

    PubMed

    Kan, Zhong-Yuan; Mayne, Leland; Chetty, Palaniappan Sevugan; 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. PMID:21952778

  15. 12 CFR Appendix Ms-3 to Part 1024 - Appendix MS-3 to Part 1024

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 12 Banks and Banking 8 2014-01-01 2014-01-01 false Appendix MS-3 to Part 1024 MS Appendix MS-3 to... ACT (REGULATION X) Pt. 1024, App. MS-3 Appendix MS-3 to Part 1024 Model Force-Placed Insurance Notice Forms Table of Contents MS-3(A)—Model Form for Force-Placed Insurance Notice Containing...

  16. LC-MS-based metabolomics

    PubMed Central

    Zhou, Bin; Xiao, Jun Feng; Tuli, Leepika

    2013-01-01

    Metabolomics aims at identification and quantitation of small molecules involved in metabolic reactions. LC-MS has enjoyed a growing popularity as the platform for metabolomic studies due to its high throughput, soft ionization, and good coverage of metabolites. The success of LC-MS-based metabolomic study often depends on multiple experimental, analytical, and computational steps. This review presents a workflow of a typical LC-MS-based metabolomic analysis for identification and quantitation of metabolites indicative of biological/environmental perturbations. Challenges and current solutions in each step of the workflow are reviewed. The review intends to help investigators understand the challenges in metabolomic studies and to determine appropriate experimental, analytical, and computational methods to address these challenges. PMID:22041788

  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. 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. PMID:26447938

  19. 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

  20. Therapeutic drug monitoring of tamoxifen using LC-MS/MS.

    PubMed

    Tchu, Simone M; Lynch, Kara L; Wu, Alan H B

    2012-01-01

    Tamoxifen is a selective estrogen receptor modulator (SERM) that is used widely in the treatment of estrogen receptor positive breast cancer (ER+). Therapeutic monitoring of tamoxifen, and its metabolites N-desmethyltamoxifen (NDTam) and 4-hydroxy-N-desmethyltamoxifen (endoxifen), may be clinically useful for guiding treatment decisions. Two significant barriers to tamoxifen efficacy are: (1) variability in conversion of tamoxifen into the potent antiestrogenic metabolite, endoxifen, and (2) poor compliance and adherence to tamoxifen therapy. Therapeutic monitoring can be used to address both of these issues. Low levels of endoxifen indicate either poor compliance or poor metabolism of tamoxifen. Low tamoxifen levels would suggest poor compliance while a low ratio of endoxifen to NDTam would be indicative of poor metabolism. Solid phase extraction of patient serum followed by liquid chromatography tandem mass spectrometry (LC-MS/MS) detection enables rapid, accurate, detection of tamoxifen, N-desmethyltamoxifen, and endoxifen. PMID:22767121

  1. 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

  2. Analysis of Marine Biotoxins Using LC-MS/MS.

    PubMed

    Luckas, Bernd; Erler, Katrin; Krock, Bernd

    2015-01-01

    Different clinical types of algae-related poisoning have attracted scientific and commercial attention: paralytic shellfish poisoning (PSP), diarrhetic shellfish poisoning (DSP), and amnesic shellfish poisoning (ASP). Bioassays are common methods for the determination of marine biotoxins. However, biological tests are not completely satisfactory, mainly due to the low sensitivity and the absence of specialized variations. In this context LC-MS methods replaced HPLC methods with optical detectors, allowing both effective seafood control and monitoring of phytoplankton in terms of the different groups of marine biotoxins. This chapter describes state-of-the-art LC-MS/MS methods for the detection and quantitation of different classes of phycotoxins in shellfish matrices. These classes include the highly hydrophilic paralytic shellfish poisoning (PSP) toxins. Hydrophilic interaction liquid chromatography (HILIC) has been shown to be useful in the separation of PSP toxins and is described in detail within this chapter. Another important class of phycotoxins is diarrhetic shellfish poisoning (DSP) toxins. This group traditionally comprises okadaic acid and dinophysistoxins (DTXs), pectenotoxins (PTXs), and yessotoxins (YTXs). The most recently described shellfish poisoning syndrome, azaspiracid shellfish poisoning (AZP) is caused by azaspiracids, which in turn are diarrhetic, but usually are treated separately as AZP. The last group of regulated shellfish toxins is the amnesic shellfish poisoning (ASP) toxin domoic acid, produced by species of the genus Pseudo-nitzschia. PMID:26108513

  3. 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. PMID:26458767

  4. 12 CFR Appendix Ms-2 to Part 1024 - Appendix MS-2 to Part 1024

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 12 Banks and Banking 8 2014-01-01 2014-01-01 false Appendix MS-2 to Part 1024 MS Appendix MS-2 to... ACT (REGULATION X) Pt. 1024, App. MS-2 Appendix MS-2 to Part 1024 NOTICE OF ASSIGNMENT, SALE, OR.... PRESENT SERVICER Date FUTURE SERVICER Date Effective Date Note: At 78 FR 10886, Feb. 14, 2013, appendix...

  5. 12 CFR Appendix Ms-1 to Part 1024 - Appendix MS-1 to Part 1024

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 12 Banks and Banking 8 2014-01-01 2014-01-01 false Appendix MS-1 to Part 1024 MS Appendix MS-1 to Part 1024 Banks and Banking BUREAU OF CONSUMER FINANCIAL PROTECTION REAL ESTATE SETTLEMENT PROCEDURES ACT (REGULATION X) Pt. 1024, App. MS-1 Appendix MS-1 to Part 1024 SERVICING DISCLOSURE...

  6. 24 CFR Appendix Ms-2 to Part 3500 - Appendix MS-2 to Part 3500

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 24 Housing and Urban Development 5 2014-04-01 2014-04-01 false Appendix MS-2 to Part 3500 MS Appendix MS-2 to Part 3500 Housing and Urban Development Regulations Relating to Housing and Urban... HOUSING AND URBAN DEVELOPMENT REAL ESTATE SETTLEMENT PROCEDURES ACT Pt. 3500, App. MS-2 Appendix MS-2...

  7. 24 CFR Appendix Ms-1 to Part 3500 - Appendix MS-1 to Part 3500

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 5 2011-04-01 2011-04-01 false Appendix MS-1 to Part 3500 MS Appendix MS-1 to Part 3500 Housing and Urban Development Regulations Relating to Housing and Urban... HOUSING AND URBAN DEVELOPMENT REAL ESTATE SETTLEMENT PROCEDURES ACT Pt. 3500, App. MS-1 Appendix MS-1...

  8. 24 CFR Appendix Ms-1 to Part 3500 - Appendix MS-1 to Part 3500

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 24 Housing and Urban Development 5 2014-04-01 2014-04-01 false Appendix MS-1 to Part 3500 MS Appendix MS-1 to Part 3500 Housing and Urban Development Regulations Relating to Housing and Urban... HOUSING AND URBAN DEVELOPMENT REAL ESTATE SETTLEMENT PROCEDURES ACT Pt. 3500, App. MS-1 Appendix MS-1...

  9. 24 CFR Appendix Ms-2 to Part 3500 - Appendix MS-2 to Part 3500

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Appendix MS-2 to Part 3500 MS Appendix MS-2 to Part 3500 Housing and Urban Development Regulations Relating to Housing and Urban... HOUSING AND URBAN DEVELOPMENT REAL ESTATE SETTLEMENT PROCEDURES ACT Pt. 3500, App. MS-2 Appendix MS-2...

  10. 24 CFR Appendix Ms-2 to Part 3500 - Appendix MS-2 to Part 3500

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 24 Housing and Urban Development 5 2012-04-01 2012-04-01 false Appendix MS-2 to Part 3500 MS Appendix MS-2 to Part 3500 Housing and Urban Development Regulations Relating to Housing and Urban... HOUSING AND URBAN DEVELOPMENT REAL ESTATE SETTLEMENT PROCEDURES ACT Pt. 3500, App. MS-2 Appendix MS-2...

  11. 24 CFR Appendix Ms-1 to Part 3500 - Appendix MS-1 to Part 3500

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Appendix MS-1 to Part 3500 MS Appendix MS-1 to Part 3500 Housing and Urban Development Regulations Relating to Housing and Urban... HOUSING AND URBAN DEVELOPMENT REAL ESTATE SETTLEMENT PROCEDURES ACT Pt. 3500, App. MS-1 Appendix MS-1...

  12. 24 CFR Appendix Ms-1 to Part 3500 - Appendix MS-1 to Part 3500

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 24 Housing and Urban Development 5 2013-04-01 2013-04-01 false Appendix MS-1 to Part 3500 MS Appendix MS-1 to Part 3500 Housing and Urban Development Regulations Relating to Housing and Urban... HOUSING AND URBAN DEVELOPMENT REAL ESTATE SETTLEMENT PROCEDURES ACT Pt. 3500, App. MS-1 Appendix MS-1...

  13. 24 CFR Appendix Ms-1 to Part 3500 - Appendix MS-1 to Part 3500

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 24 Housing and Urban Development 5 2012-04-01 2012-04-01 false Appendix MS-1 to Part 3500 MS Appendix MS-1 to Part 3500 Housing and Urban Development Regulations Relating to Housing and Urban... HOUSING AND URBAN DEVELOPMENT REAL ESTATE SETTLEMENT PROCEDURES ACT Pt. 3500, App. MS-1 Appendix MS-1...

  14. 24 CFR Appendix Ms-2 to Part 3500 - Appendix MS-2 to Part 3500

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 5 2011-04-01 2011-04-01 false Appendix MS-2 to Part 3500 MS Appendix MS-2 to Part 3500 Housing and Urban Development Regulations Relating to Housing and Urban... HOUSING AND URBAN DEVELOPMENT REAL ESTATE SETTLEMENT PROCEDURES ACT Pt. 3500, App. MS-2 Appendix MS-2...

  15. 24 CFR Appendix Ms-2 to Part 3500 - Appendix MS-2 to Part 3500

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 24 Housing and Urban Development 5 2013-04-01 2013-04-01 false Appendix MS-2 to Part 3500 MS Appendix MS-2 to Part 3500 Housing and Urban Development Regulations Relating to Housing and Urban... HOUSING AND URBAN DEVELOPMENT REAL ESTATE SETTLEMENT PROCEDURES ACT Pt. 3500, App. MS-2 Appendix MS-2...

  16. Analysis of 136 pesticides in avocado using a modified QuEChERS method with LC-MS/MS and GC-MS/MS.

    PubMed

    Chamkasem, Narong; Ollis, Lisa W; Harmon, Tiffany; Lee, Sookwang; Mercer, Greg

    2013-03-13

    A simple and high-throughput screening method for the analysis of 136 pesticides in avocado ( Persea americana ) by LC-(+)-ESI-MS/MS and GC-MS/MS is presented. A modified QuEChERS sample preparation method was developed to improve the extraction recovery of highly lipophilic pesticides. Extracts from minced avocados after acetonitrile (MeCN) extraction were directly injected to LC-MS/MS, whereas other GC-amenable compounds were treated with the modified QuEChERS procedure for GC-MS/MS analysis. The average recoveries for 79 pesticides quantified by LC-MS/MS at 10, 50, and 200 ng/g fortifying levels were 86.1% or better (with maximum RSD at 9.2%), whereas GC-MS/MS analysis demonstrated 70.2% or better (RSD < 18%) for average recovery from 57 compounds at the same spike levels. The application of LC- and GC-MS/MS combined with the improved extraction procedures led to the current method, which can quantitate these pesticides even if they are present in avocados below the targeted action level by FDA. This method demonstrated the improved recovery of several challenging lipophilic pesticides in highly fat-rich avocados. PMID:23362971

  17. 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.

  18. 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.

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  20. Determination of sterigmatocystin in feed by LC-MS/MS.

    PubMed

    Biancardi, Alberto; Dall'Asta, Chiara

    2015-01-01

    An LC-MS/MS method is proposed for the analysis of sterigmatocystin in cereals and feed. The method is based on a solid-liquid extraction and a dilute-and-shoot approach. Accuracy and precision were established at the LOQ (1 μg kg(-1)); the mean overall recovery (n = 6) was 98%, with a confidence interval of 3.8% and a CV% of 3.7%. Accuracy and precision were also assessed at three other concentration levels (2.03, 5.07 and 10.14 μg kg(-1); six replicates per level). The mean overall recovery (n = 24, LOQ included) was 99% with a confidence interval of 0.8% and a CV% of 1.9%. The method was then applied to 14 naturally incurred feed samples. Aflatoxin B1 was present in the range 28.7-240.1 µg kg(-1), while lower concentrations of sterigmatocystin were found (0.7-2.2 µg kg(-1)). This method may represent a valuable choice, ensuring a high level of accuracy and precision, as well as high-throughput performance. Therefore, it meets the recent EFSA opinion recommendation in terms of availability of fast and sensitive methods (recommended LOQ = 1.5 μg kg(-1)) in order to increase data collection to allow for the assessment of dietary exposure. PMID:26471726

  1. Analysis of serum proteins by LC-MS/MS.

    PubMed

    Tonack, Sarah; Neoptolemos, John P; Costello, Eithne

    2010-01-01

    Serum contains a vast array of proteins, some of which are specific to blood whilst others are secreted into blood from tissues and organs. The so-called tissue leakage factors reveal information about the tissue from which they originate and are therefore of great potential importance as disease biomarkers. There are already a number of blood-borne biomarkers in routine clinical use that aid in the diagnosis or management of cancer. However, there is a pressing need for additional markers, and new methods to find them are under development. Here we provide a protocol for serum protein profiling using liquid chromatography tandem mass spectrometry (LC-MS/MS). Included in this procedure, we detail the pre-processing steps of lipid and high-abundance protein removal. These procedures can also be employed up-stream of quantification methods such as isobaric tags for relative and absolute quantification (iTRAQ). Chapter 12 is devoted to the iTRAQ approach for quantifying proteins, and it is therefore not described in this chapter. PMID:20839111

  2. LC-MS/MS determination of tralopyril in water samples.

    PubMed

    Oliveira, Isabel B; Schönenberger, René; Barroso, Carlos M; Suter, Marc J-F

    2016-02-01

    A targeted analytical method was established to determine tralopyril (4-bromo-2-(4-chlorophenyl)-5-(trifluoromethyl)-1H-pyrrole-3-carbonitrile) in water. This compound has been recently introduced as a biocide in ship antifouling paints, becoming a potential new environmental contaminant. The method presented here allows for the first time the direct determination of tralopyril in environmental samples without the need of a pre-concentration step. The injected sample is separated by a 30 min HPLC-gradient on a reversed phase column and the compound identified and quantified by negative ion LC-MS/MS. Tralopyril solutions in DMSO, seawater, river Glatt water and E3 medium (used for zebrafish experiments) were analysed to demonstrate the applicability of the method. The method provides good retention time reproducibility and a quantitation limit (LOQ) of 0.025 μg L(-1) for DMSO, seawater and E3 exposure medium and 0.05 μg L(-1) for river Glatt water. Calculated tralopyril half-lives were 6.1 h for seawater, 8.1 h for river Glatt water and 7.4 h for E3 medium at 18 °C. PMID:26694794

  3. 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.

  4. Determination of five macrolide antibiotic residues in honey by LC-ESI-MS and LC-ESI-MS/MS.

    PubMed

    Wang, Jian

    2004-01-28

    Liquid chromatography-electrospray ionization mass spectrometry methods (LC-ESI-MS and LC-ESI-MS/MS) for the determination of five macrolide antibiotics including spiramycin, tilmicosin, oleandomycin, erythromycin, and tylosin in honey are presented. Macrolides were protonated to form singly and/or doubly charged pseudomolecular ions, depending on their chemical structures, in an electrospray positive ionization mode. Data acquisition under MS/MS was achieved by applying multiple reaction monitoring (MRM) of two or three fragment ion transitions to provide a high degree of sensitivity and specificity. The recoveries, that is, determined by LC-ESI-MS/MS, of the five macrolides at fortified levels of 6, 16, 40, and 80 microg/kg ranged from 75.5 to 135.7% in light honey and from 42.1 to 111.0% in dark honey. The ion ratios obtained under MS/MS were key criteria to confirm the identity of macrolides in incurred samples. LC-ESI-MS/MS method detection limits of the five macrolides were <0.1 microg/kg. PMID:14733491

  5. 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. PMID:23603165

  6. 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

  7. Using the Doubly Charged Selected Ion Coupled with MS/MS Fragments Monitoring (DCSI-MS/MS) Mode for the Identification of Gelatin Species.

    PubMed

    Cheng, Xian-Long; Wei, Feng; Chen, Jia; Li, Ming-Hua; Zhang, Lei; Zhao, Ying-Yong; Xiao, Xin-Yue; Ma, Shuang-Cheng; Lin, Rui-Chao

    2014-01-01

    In electrospray ionization (ESI) mode, peptides and proteins can be multiply charged ions; in this situation a doubly charged selected ion (DCSI) coupled with mass spectrometry (MS/MS) fragments monitoring (DCSI-MS/MS) method is the most suitable scanning mode to detect known peptides in complex samples when an ion-trap mass spectrometer is the instrument used for the analysis. In this mode, the MS detector is programmed to only select a doubly charged ion as a precursor and to perform continuous MS/MS on one or more of the selected precursors, either during a specific time interval or along the whole chromatographic run. Gelatin is a mixture of high molecular weight polypeptides from the hydrolysis of collagen. In this study, the DCSI-MS/MS monitoring mode was applied to the detection of previously characterized species-specific peptides from different gelatins. The proposed methodology makes use of tryptic digestion for sample preparation and peptide separation and identification by rapid resolution liquid chromatography coupled to an ion trap working in the DCSI-MS/MS mode for the analysis. This methodology was applied to the differential classification of five commercial, homological species of gelatins and proved to be an excellent tool for gelatin product authentication. PMID:24744960

  8. 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

  9. Metabolite Fingerprinting of Eugenia jambolana Fruit Pulp Extracts using NMR, HPLC-PDA-MS, GC-MS, MALDI-TOF-MS and ESI-MS/MS Spectrometry.

    PubMed

    Sharma, Ram Jee; Gupta, Ramesh C; Bansal, Arvind Kumar; Singh, Inder Pal

    2015-06-01

    Eugenia jambolana, commonly known as 'jamun' or Indian blackberry, is an important source of bioactive compounds. All parts of the plant like stem bark, leaves, flower, fruit pulp and seeds are traditionally used for many diseases. Metabolite profiling in medicinally important plants is critical to resolve the problems associated with standardization and quality control. Metabolite profiling of the fruit pulp of Jamun was performed by NMR, HPLC, MS, GC-MS and MALDI-TOF mass spectrometry. These hyphenated techniques helped in the identification of 68 chemically-diverse metabolites of the fruit pulp. These include anthocyanins, anthocyanidins, sugars, phenolics and volatile compounds. Five extracts of fruit pulp were prepared i.e. hexane, chloroform, ethylacetate, butanol and aqueous methanolic. Twenty-five metabolites identified and quantified in the n-butanol and aqueous-methanolic extracts of ripe jamun fruit by qNMR. LC-PDA-MS and MALDI-TOF spectrometry helped in deciphering thirty-nine metabolites out of which thirteen were quantified. PMID:26197529

  10. Immunomodulatory treatments and cognition in MS.

    PubMed

    Mückschel, M; Beste, C; Ziemssen, T

    2016-09-01

    Cognitive impairments occur frequently and early in multiple sclerosis (MS) and contribute significantly to a reduced quality of life of patients with MS. Executive functions (EFs) play a pivotal role for the behavioral adaption to the environment and are also crucial for compensatory processes of cognitive impairments. Disease-modifying drugs (DMDs) are effective in reducing the frequency of relapses and slow the disease progression in MS. The effects of DMDs on cognitive impairments were reviewed with a special focus on EFs. Most studies show some beneficial effects of DMDs on cognition in MS, but the evidence for effects on EFs is sparse. Additionally, most studies suffer from methodological issues, small sample sizes and learning effects. We discuss that EFs may constitute a viable cognitive endpoint for cognitive impairments in MS, which could foster the early detection of subtle cognitive changes in MS. PMID:27580907

  11. 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

  12. Measurement of oxidative stress parameters using liquid chromatography-tandem mass spectroscopy (LC-MS/MS)

    SciTech Connect

    Winnik, Witold M. Kitchin, Kirk T.

    2008-11-15

    There is increasingly intense scientific and clinical interest in oxidative stress and the many parameters used to quantify the degree of oxidative stress. However, there remain many analytical limitations to currently available assays for oxidative stress markers. Recent improvements in software, hardware, and instrumentation design have made liquid chromatography and tandem mass spectroscopy (LC-MS/MS) methods optimal choices for the determination of many oxidative stress markers. In particular, LC-MS/MS often provides the advantages of higher specificity, higher sensitivity, and the capacity to determine multiple analytes (e.g. 4-11 oxidative stress markers per LC run) when compared to other available methods, such as gas chromatography-MS, immunoassays, spectrophotometric or flourometric assays. LC-MS/MS methods are also compatible with cleanup and sample preparation methods including prior solid phase extraction or automated two dimensional LC/LC chromatography followed by MS/MS. LC-MS/MS provides three analytical filtering functions: (1) the LC column provides initial separation as each analyte elutes from the column. (2) The first MS dimension isolates ions of a particular mass-to-charge (m/z) ratio. (3) The selected precursor ion is fragmented into product ions that provide structural information about the precursor ion. Quantitation is achieved based on the abundances of the product ions. The sensitivity limits for LC-MS/MS usually lie within the range of fg-pg of analyte per LC on-column injection. In this article, the present capabilities of LC-MS/MS are briefly presented and some specific examples of the strengths of these LC-MS/MS assays are discussed. The selected examples include methods for isoprostanes, oxidized proteins and amino acids, and DNA biomarkers of oxidative stress.

  13. 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

  14. Rapid screening and characterization of drug metabolites using a multiple ion monitoring-dependent MS/MS acquisition method on a hybrid triple quadrupole-linear ion trap mass spectrometer.

    PubMed

    Yao, Ming; Ma, Li; Humphreys, W Griffith; Zhu, Mingshe

    2008-10-01

    A novel LC/MS/MS method that uses multiple ion monitoring (MIM) as a survey scan to trigger the acquisition of enhanced product ions (EPI) on a hybrid quadrupole-linear ion trap mass spectrometer (Q TRAP) was developed for drug metabolite identification. In the MIM experiment, multiple predicted metabolite ions were monitored in both Q1 and Q3. The collision energy in Q2 was set to a low value to minimize fragmentation. Results from analyzing ritonavir metabolites in rat hepatocytes demonstrate that MIM-EPI was capable of targeting a larger number of metabolites regardless of their fragmentation and retained sensitivity and duty cycle similar to multiple reaction monitoring (MRM)-EPI. MIM-based scanning methods were shown to be particularly useful in several applications. First, MIM-EPI enabled the sensitive detection and MS/MS acquisition of up to 100 predicted metabolites. Second, MIM-MRM-EPI was better than MRM-EPI in the analysis of metabolites that undergo either predictable or unpredictable fragmentation pathways. Finally, a combination of MIM-EPI and full-scan MS (EMS), as an alternative to EMS-EPI, was well suited for routine in vitro metabolite profiling. Overall, MIM-EPI significantly enhanced the metabolite identification capability of the hybrid triple quadrupole-linear ion trap LC/MS. PMID:18416441

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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. The same can not be said for nLC-MALDI MS/MS which has yet to experience such wide spread acceptance. This is not totally surprising given th...

  17. Bioanalytical method validation considerations for LC-MS/MS assays of therapeutic proteins.

    PubMed

    Duggan, Jeffrey X; Vazvaei, Faye; Jenkins, Rand

    2015-01-01

    This paper highlights the recommendations of a group of industry scientists in validating regulated bioanalytical LC-MS/MS methods for protein therapeutics in a 2015 AAPSJ White Paper. This group recommends that most of the same precision and accuracy validation criteria used for ligand-binding assays (LBAs) be applied to LC-MS/MS-based assays where proteins are quantified using the LC-MS/MS signal from a surrogate peptide after proteolytic digestion (PrD-LCMS methods). PrD-LCMS methods are generally more complex than small molecule LC-MS/MS assays and may often include LBA procedures, leading to the recommendation for a combination of chromatographic and LBA validation strategies and appropriate acceptance criteria. Several key aspects of this bioanalytical approach that are discussed in the White Paper are treated here in additional detail. These topics include selectivity/specificity, matrix effect, digestion efficiency, stability and critical reagent considerations. PMID:26110712

  18. Coal tar analysis by LC/MS

    SciTech Connect

    Herod, A.A.; Ladner, W.R.; Stokes, B.J.; Berry, A.J.; Games, D.E.

    1986-04-01

    The application of LC/MS to the analysis of an aromatic fraction of a hydropyrolysis tar is described. The results are compared with those obtained by GC/MS, low eV probe mass spectrometry and field desorption mass spectrometry.

  19. Oxidized and nitrated oleic acid in biological systems: analysis by GC-MS/MS and LC-MS/MS, and biological significance.

    PubMed

    Tsikas, Dimitrios; Zoerner, Alexander A; Jordan, Jens

    2011-11-01

    Compared to the arachidonic acid (C20:4) cascade, the oleic acid (C18:1) family comprises a handful known metabolites. The pathophysiology of oleic acid and its oxidized and nitrated metabolites, i.e., cis-9,10-epoxyoctadecanoic acid (cis-EpOA) and the two vinylic nitro-oleic acids cis-9-nitro-oleic acid (9-NO(2)-OA) and cis-10-nitro-oleic acid (10-NO(2)-OA), is only little investigated and little understood. cis-EpOA, 9-NO(2)-OA and 10-NO(2)-OA have been detected in plasma of healthy and ill human subjects by means of gas chromatography-tandem mass spectrometry (GC-MS/MS) and liquid chromatography-tandem mass spectrometry (LC-MS/MS) techniques in their acid and esterified forms. cis-EpOA is formed from oleic acid by the catalytic action of various cytochrome P450 isozymes. In end-stage liver disease, cis-EpOA plasma concentration is lower than in healthy subjects suggesting liver as the main organ responsible for cis-EpOA synthesis. The origin of 9-NO(2)-OA and 10-NO(2)-OA and of other nitrated oleic acid metabolites is unknown. In vitro models, nitro-oleic acid species can be formed non-enzymatically from oleic acid and nitrogen dioxide. Thus, endogenous nitro-oleic acids could serve as biomarkers of fatty acid nitration by reactive nitrogen species. Synthetic 9-NO(2)-OA and 10-NO(2)-OA at concentrations of three orders of magnitude higher than their endogenous counterparts have interesting pharmacological features and are currently intensely investigated. The present article reviews and discusses currently available analytical methods for the quantitative determination of cis-EpOA, 9-NO(2)-OA and 10-NO(2)-OA in biological samples, notably in human plasma, and the potential biological significance of these oleic acid metabolites. Special emphasis is given to GC-MS/MS and LC-MS/MS methods utilizing the stable-isotope dilution technique. The sensitivity and specificity of the MS/MS approach make electron-capture negative ion chemical ionization (ECNICI) GC-MS/MS

  20. Ellagitannin Composition of Blackberry As Determined by HPLC-ESI-MS and MALDI-TOF-MS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Apache blackberries (Rubus sp.) were evaluated by HPLC-MS and MALDI-TOF-MS to identify ellagitannins present in the flesh, torus (receptacle tissue), and seeds. Most ellagitannins were only present or detectable in seed tissues. Ellagitannins identified by HPLC-MS in the seeds included pedunculagi...

  1. Metabolomics Data Normalization with EigenMS

    PubMed Central

    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. PMID:25549083

  2. 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. PMID:25549083

  3. Integrated metabolomic profiling of hepatocellular carcinoma in hepatitis C cirrhosis through GC/MS and UPLC/MS-MS

    PubMed Central

    Fitian, Asem I.; Nelson, David R.; Liu, Chen; Xu, Yiling; Ararat, Miguel; Cabrera, Roniel

    2014-01-01

    Background & Aims The metabolic pathway disturbances associated with hepatocellular carcinoma (HCC) remain unsatisfactorily characterized. Determination of the metabolic alterations associated with the presence of HCC can improve our understanding of the pathophysiology of this cancer and may provide opportunities for improved disease monitoring of patients at risk for HCC development. To characterize the global metabolic alterations associated with HCC arising from hepatitis C (HCV)-associated cirrhosis using an integrated non-targeted metabolomics methodology employing both gas chromatography/mass spectrometry (GC/MS) and ultrahigh-performance liquid chromatography/electrospray ionization tandem mass spectrometry (UPLC/MS-MS). Methods The global serum metabolomes of 30 HCC patients, 27 hepatitis C cirrhosis disease controls and 30 healthy volunteers were characterized using a metabolomics approach that combined two metabolomics platforms, GC/MS and UPLC/MS-MS. Random forest, multivariate statistics and receiver operator characteristic analysis were performed to identify the most significantly altered metabolites in HCC patients vs. HCV-cirrhosis controls and which therefore exhibited a close association with the presence of HCC. Results Elevated 12-hydroxyeicosatetraenoic acid (12-HETE), 15-HETE, sphingosine, γ-glutamyl oxidative stress-associated metabolites, xanthine, amino acids serine, glycine and aspartate, and a-cylcarnitines were strongly associated with the presence of HCC. Elevations in bile acids and dicarboxylic acids were highly correlated with cirrhosis. Conclusions Integrated metabolomic profiling through GC/MS and UPLC/MS-MS identified global metabolic disturbances in HCC and HCV-cirrhosis. Aberrant amino acid biosynthesis, cell turnover regulation, reactive oxygen species neutralization and eicosanoid pathways may be hallmarks of HCC. Aberrant dicarboxylic acid metabolism, enhanced bile acid metabolism and elevations in fibrinogen cleavage

  4. 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

  5. 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. PMID:27241820

  6. 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.

  7. 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

  8. 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 ofd- andl-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 usingl-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- orl-isomer even for enantiomerically pure standards. A higher rate ofd- andl-methamphetamine isomer racemization is seen in samples when analyzed by GC-MS usingl-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. PMID:26869715

  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. [Multiresidue method for pesticides and veterinary drugs in bovine milk using GC/MS and LC/MS/MS].

    PubMed

    Saito, Mizue; Kozutsumi, Daisuke; Kawasaki, Michiko; Kanbashi, Miho; Nakamura, Ruka; Sato, Yoshio; Endo, Mitsuharu

    2008-06-01

    A simple, sensitive and selective method with gas chromatography/mass spectrometry (GC/MS) and liquid chromatography/tandem mass spectrometry (LC/MS/MS) has been developed to detect 342 pesticides and veterinary drugs contaminating bovine milk at the maximum residue limits (MRLs) defined in the "positive list system". Sample preparation was performed by extracting the analytes with acetonitrile, followed by salting-out with sodium chloride. For some pesticides, the extract was further cleaned up by n-hexane partitioning and PSA cartridge column chromatography. GC/MS-EI or -NCI was used to determine pesticide residues, while LC/MS/MS-ESI was applicable to the determination of pesticide and veterinary drug residues. The variation of the recoveries of these drugs at MRL was relatively wide; however the relative standard deviations of the recovery of each drug were within 28%, suggesting that the present method is good enough for use as a screening test for contaminants at the MRLs. These results show that this method is useful for multiresidue analysis of numerous pesticides and veterinary drugs in bovine milk. PMID:18633208

  11. 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.

  12. Dealing with MS in Your Important Relationships

    MedlinePlus

    ... chronic illness like MS can be deeply satisfying. Spouses and partners, family, and friends can be drawn more closely together by their shared concerns and collaborative efforts. But caregiving (.pdf) can ...

  13. At Home with MS: Adapting Your Environment

    MedlinePlus

    ... of things you almost never need. Your storage adaptations may include hanging baskets, rolling storage carts, peg ... living at home with a disability. n Any adaptation or renovation to help you cope with MS ...

  14. CLaMS: Classifier for Metagenomic Sequences

    Energy Science and Technology Software Center (ESTSC)

    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 applicationmore » 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.« less

  15. 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

  16. Challenges and benefits of endogenous steroid analysis by LC-MS/MS.

    PubMed

    Couchman, Lewis; Vincent, Royce P; Ghataore, Lea; Moniz, Caje F; Taylor, Norman F

    2011-11-01

    Quantification of endogenous hormonal steroids and their precursors is essential for diagnosing a wide range of endocrine disorders. Historically, these analyses have been carried out using immunoassay, but such methods are problematic, especially for low-concentration analytes, due to assay interference by other endogenous steroids. MS offers improved specificity over immunoassay and can be highly sensitive. GC-MS, with use of stable isotopically labeled internal standards, is considered the 'gold standard' method for serum steroid analysis. GC-MS is the method of choice for profiling steroid metabolites in urine, but these techniques are not appropriate for routine use in clinical laboratories owing to a need for extensive sample preparation, as well as analytical expertise. LC-MS/MS compares well to GC-MS in terms of accuracy, precision and sensitivity, but allows simplified sample preparation. While most publications have featured only one or a limited number of steroids, we consider that steroid paneling (which we propose as the preferred term for multitargeted steroid analysis) has great potential to enable clinicians to make a definitive diagnosis. It is adaptable for use in a number of matrices, including serum, saliva and dried blood spots. However, LC-MS/MS-based steroid analysis is not straightforward, and understanding the chemical and analytical processes involved is essential for implementation of a robust clinical service. This article discusses specific challenges in the measurement of endogenous steroids using LC-MS/MS, and provides examples of the benefits it offers. PMID:22122603

  17. 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. PMID:25682618

  18. 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

  19. Expert system for computer-assisted annotation of MS/MS spectra.

    PubMed

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

    2012-11-01

    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

  20. 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.

  1. Cognitive impairment in MS: rehabilitation approaches.

    PubMed

    Hämäläinen, P; Rosti-Otajärvi, E

    2016-09-01

    Cognitive deficits have been reported in 45%-70% of patients with multiple sclerosis (MS). Like other symptoms of MS, cognitive deficits are highly variable. Slowed information processing and memory and learning dysfunction are regarded as the most frequent cognitive deficits in MS. Both white and gray matter damages have been suggested to contribute to cognitive impairments in MS. There is no direct relationship between cognitive deficits and physical disability, disease duration or course of the disease. In addition to cognitive impairments, neuropsychiatric symptoms are observed in MS, the most common being alterations in mood state. Neurobehavioral deficits have multidimensional effects on the activities of daily living and quality of life. Consequently, attention should be paid to early diagnosis and treatment. Based on studies on cognitive retraining and more multimodal neuropsychological rehabilitation, both approaches show promise in the treatment of cognitive impairments and their harmful effects. This review introduces the frequency and characteristics of cognitive impairments, as well as main findings on the effects of neuropsychological rehabilitation in MS. PMID:27580900

  2. High-throughput quantification of drugs and their metabolites in biosamples by LC-MS/MS and CE-MS/MS: possibilities and limitations.

    PubMed

    Hopfgartner, G; Husser, C; Zell, M

    2002-02-01

    Off-line solid phase extraction with C18 disk plates and turbulent flow chromatography were evaluated versus on-line solid phase extraction using column-switching HPLC as sample preparation techniques for high-throughput analysis of pharmaceutical compounds and their metabolites by LC-MS/MS. Turbulent flow chromatography was found to be very straightforward in its applicaton, but the LOQs were more than fivefold higher compared with off-line or other on-line solid phase extraction methods. Solid phase extraction (SPE) on disk was found to be fast and sufficient efficient to minimize matrix effects and therefore an apprach to provide sensitive and reliable LC-MS/MS methods. Column-switching HPLC with microbore columns (0.5 mm i.d.) were used for fast analysis of a parent drug and four of its metabolites utilizing steep gradients in 1 minute. The application of CZE-MS/MS for bionalysis of pharamaceutical compounds is also discussed. PMID:11805734

  3. 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

  4. Implementing the Professional Development Standards: An Innovative M.S. Degree for High School Chemistry Teachers

    NASA Astrophysics Data System (ADS)

    Lowery Bretz, Stacey

    2002-11-01

    The 1996 publication of the National Science Education Standards (NSES)em> has had a profound effect on curriculum development, assessment of student learning, and pre-service teacher education. One consequence of this at the state level has been the abandonment of permanent certification for K-12 teachers in favor of renewable licensure. Ohio and Pennsylvania now require secondary teachers to earn an M.S. within ten years of their B.S. However, the NSESem> for professional development have yet to receive emphasis and priority in implementation equal to that given the content standards. For high school chemistry teachers, existing M.S. programs fail to meet the NSESem> professional development guidelines. This report outlines a vision for a new kind of masters' degree, tailored to the needs and talents of high school chemistry teachers, which provides for integration of both pedagogical knowledge and content knowledge (chemistry). The program empowers teachers with the skills necessary for continual professional development throughout their careeers by using action research in the high school classroom. Graduate courses in chemistry education research, including an extensive annotated bibliography, and early evaluation results are reported.

  5. 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.

  6. 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.

  7. Simultaneous determination of six constituents in Mahuang Fuzi Xixin by UPLC-PDA-MS/MS.

    PubMed

    Zhang, Lin; Wang, Chengying; Miao, Dezu; Yuan, Dan; Bi, Kaishun; Yang, Jingyu; Zhan, Libin

    2015-01-01

    Mahuang Fuzi Xixin (MFX), a classic recipe in traditional Chinese medicine, belongs to an exterior-relieving formula. For quality control of the MFX products, qualitative analysis using ultra-high performance liquid chromatography with diode-array detector-tandem mass spectrometry (UPLC-PDA-MS/MS) was undertaken. Six compounds from the MFX were simultaneously detected. Among them, astragalin and kaempferol 3-rutinoside were quantified through the UPLC-MS/MS method, while asarinin, sesamin, kakuol and methyleugenol were quantified through the UPLC-PDA method. This method can be applied to the quantitative determination of the six compounds in the MFX. PMID:25428280

  8. MassSieve: panning MS/MS peptide data for proteins.

    PubMed

    Slotta, Douglas J; McFarland, Melinda A; Markey, Sanford P

    2010-08-01

    We present MassSieve, a Java-based platform for visualization and parsimony analysis of single and comparative LC-MS/MS database search engine results. The success of mass spectrometric peptide sequence assignment algorithms has led to the need for a tool to merge and evaluate the increasing data set sizes that result from LC-MS/MS-based shotgun proteomic experiments. MassSieve supports reports from multiple search engines with differing search characteristics, which can increase peptide sequence coverage and/or identify conflicting or ambiguous spectral assignments. PMID:20564260

  9. 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.

  10. Online LC-FAIMS-MS/MS for the Analysis of Phosphorylation in Proteins.

    PubMed

    Zhao, Hongyan; Creese, Andrew J; Cooper, Helen J

    2016-01-01

    High-field asymmetric waveform ion mobility spectrometry (FAIMS) is a gas-phase separation technique which, when coupled with liquid chromatography tandem mass spectrometry, offers benefits for analysis of complex proteomics samples such as those encountered in phosphoproteomics experiments. Results from LC-FAIMS-MS/MS are typically complementary, in terms of proteome coverage and isomer identification, to those obtained by use of solution-phase separation methods, such as prefractionation with strong cation-exchange chromatography. Here, we describe the protocol for large-scale phosphorylation analysis by LC-FAIMS-MS/MS. PMID:26584930

  11. 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. PMID:14664505

  12. 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.

  13. pGlyco: a pipeline for the identification of intact N-glycopeptides by using HCD- and CID-MS/MS and MS3

    PubMed Central

    Zeng, Wen-Feng; Liu, Ming-Qi; Zhang, Yang; Wu, Jian-Qiang; Fang, Pan; Peng, Chao; Nie, Aiying; Yan, Guoquan; Cao, Weiqian; Liu, Chao; Chi, Hao; Sun, Rui-Xiang; Wong, Catherine C. L.; He, Si-Min; Yang, Pengyuan

    2016-01-01

    Confident characterization of the microheterogeneity of protein glycosylation through identification of intact glycopeptides remains one of the toughest analytical challenges for glycoproteomics. Recently proposed mass spectrometry (MS)-based methods still have some defects such as lack of the false discovery rate (FDR) analysis for the glycan identification and lack of sufficient fragmentation information for the peptide identification. Here we proposed pGlyco, a novel pipeline for the identification of intact glycopeptides by using complementary MS techniques: 1) HCD-MS/MS followed by product-dependent CID-MS/MS was used to provide complementary fragments to identify the glycans, and a novel target-decoy method was developed to estimate the false discovery rate of the glycan identification; 2) data-dependent acquisition of MS3 for some most intense peaks of HCD-MS/MS was used to provide fragments to identify the peptide backbones. By integrating HCD-MS/MS, CID-MS/MS and MS3, intact glycopeptides could be confidently identified. With pGlyco, a standard glycoprotein mixture was analyzed in the Orbitrap Fusion, and 309 non-redundant intact glycopeptides were identified with detailed spectral information of both glycans and peptides. PMID:27139140

  14. LC-MS/MS in endocrinology: what is the profit of the last 5 years?

    PubMed

    Ackermans, Mariëtte Theodora; Endert, Erik

    2014-01-01

    Currently, chromatography (GC but more commonly HPLC) is the analytical method of choice for several hormones, either because the immunoassays suffer from extensive crossreactivity or because chromatography permits simultaneous measurements of hormones. However, sometimes the conventional detection systems with HPLC methods do not meet desired specificity. With the increase of robust and affordable LC-MS/MS systems, the next step forward in specificity was taken. LC-MS/MS is rapidly being incorporated in the endocrine laboratories. To be useful in the clinical diagnostic practice, it is of utmost importance that methods are both analytically and clinically vaidated, as until now, the majority of applications of LC-MS/MS in the clinical laboratories are 'home-made' methods, therefore special case must be taken. This review aims to focus on Clinical and Laboratory Standards Institute or comparable validated LC-MS/MS methods for targeted hormone analysis used for diagnostic purposes in human samples, published in the last 5 years. PMID:24341494

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  16. STS-33 MS Musgrave and MS Carter perform balancing act on OV-103's middeck

    NASA Technical Reports Server (NTRS)

    1989-01-01

    STS-33 Mission Specialist (MS) F. Story Musgrave demonstrates a microgravity trick by balancing MS Manley L. Carter, Jr on his index finger. During the performance on Discovery's, Orbiter Vehicle (OV) 103's, middeck, Carter freefloats at the middeck ceiling while Musgrave supports him from underneath. On the forward middeck lockers is a PURDUE Boilermakers decal.

  17. 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 useof 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. Biotechnol. Bioeng. 2016;113: 1137-1147. © 2015 Wiley Periodicals, Inc. PMID:26479486

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  1. 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...

  2. IDENTIFICATION OF TRIFLURALIN METABOLITIES IN SOIL USING ION-TRAP LC/MS/MS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Trifluralin degradation in soils is complex, potentially resulting in the formation of 28 metabolites. The objective of this research was to develop an approach for the identification of trifluralin metabolites in soils using ion-trap LC/mass spectrometry (ion-trap LC/MS/MS). Authentic standards of ...

  3. DETERMINATION AND CONFIRMATION OF NITROFURAN RESIDUES IN HONEY USING LC-MS/MS.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A method was developed for the determination and confirmation of furazolidone, nitrofurazone, furaltadone, and nitrofurantoin residues as their metabolites in honey using liquid chromatography tandem mass spectrometry (LC-MS/MS). An initial solid-phase-extraction cleanup of the honey samples was fol...

  4. Multiple structure alignment with msTALI

    PubMed Central

    2012-01-01

    Background Multiple structure alignments have received increasing attention in recent years as an alternative to multiple sequence alignments. Although multiple structure alignment algorithms can potentially be applied to a number of problems, they have primarily been used for protein core identification. A method that is capable of solving a variety of problems using structure comparison is still absent. Here we introduce a program msTALI for aligning multiple protein structures. Our algorithm uses several informative features to guide its alignments: torsion angles, backbone Cα atom positions, secondary structure, residue type, surface accessibility, and properties of nearby atoms. The algorithm allows the user to weight the types of information used to generate the alignment, which expands its utility to a wide variety of problems. Results msTALI exhibits competitive results on 824 families from the Homstrad and SABmark databases when compared to Matt and Mustang. We also demonstrate success at building a database of protein cores using 341 randomly selected CATH domains and highlight the contribution of msTALI compared to the CATH classifications. Finally, we present an example applying msTALI to the problem of detecting hinges in a protein undergoing rigid-body motion. Conclusions msTALI is an effective algorithm for multiple structure alignment. In addition to its performance on standard comparison databases, it utilizes clear, informative features, allowing further customization for domain-specific applications. The C++ source code for msTALI is available for Linux on the web at http://ifestos.cse.sc.edu/mstali. PMID:22607234

  5. 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. PMID:23158326

  6. 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. PMID:16443366

  7. LC-IMS-MS Feature Finder

    Energy Science and Technology Software Center (ESTSC)

    2013-03-07

    LC-IMS-MS Feature Finder is a command line software application which searches for possible molecular ion signatures in multidimensional liquid chromatography, ion mobility spectrometry, and mass spectrometry data by clustering deisotoped peaks with similar monoisotopic mass values, charge states, elution times, and drift times. The software application includes an algorithm for detecting multiple conformations and co-eluting species in the ion mobility dimension. LC-IMS-MS Feature Finder is designed to create an output file with detected features thatmore » includes associated information about the detected features.« less

  8. LC-IMS-MS Feature Finder

    SciTech Connect

    2013-03-07

    LC-IMS-MS Feature Finder is a command line software application which searches for possible molecular ion signatures in multidimensional liquid chromatography, ion mobility spectrometry, and mass spectrometry data by clustering deisotoped peaks with similar monoisotopic mass values, charge states, elution times, and drift times. The software application includes an algorithm for detecting multiple conformations and co-eluting species in the ion mobility dimension. LC-IMS-MS Feature Finder is designed to create an output file with detected features that includes associated information about the detected features.

  9. Assessing cocaine abuse using LC-MS/MS measurements in biological specimens.

    PubMed

    Barroso, Mário; Gallardo, Eugenia

    2015-01-01

    Cocaine use is still a problem in today's world, and this has several implications on human activities. Indeed, important problems related to cocaine derive from its use in situations where concentration and focus skills are necessary, namely while driving and/or working. The need of analytical methods for drug analysis in specimens of biological origin for proper documentation of human exposure is increasing. While GC-MS-based procedures represented the state-of-the-art of analytical techniques a few years ago, there is a growing trend for their replacement by LC-MS/MS, which can be justified by the increased sensitivity presented by these new technologies. This paper will review recently published papers on the use of LC-MS/MS-based procedures for cocaine measurement in biological specimens. PMID:26168256

  10. 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. PMID:27052850

  11. 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. PMID:26538543

  12. GC/MS on an LC/MS instrument using atmospheric pressure photoionization

    NASA Astrophysics Data System (ADS)

    McEwen, Charles N.

    2007-01-01

    Atmospheric pressure (AP) GC/MS was first introduced by Horning et al. [E.C. Horning, M.G. Horning, D.I. Carroll, I. Dzidic, R.N. Stillwell, Anal. Chem. 45 (1973) 936] using 63Ni as a beta-emitter for ionization. Because, at the time special instrumentation was required, the technique was only applied with consistency to negative ion environmental studies where high sensitivity was required [T. Kinouchi, A.T.L. Miranda, L.G. Rushing, F.A. Beland, W.A. Korfmacher, J. High Resolut. Chromatogr., Chromatogr. Commun. 13 (1990) 281]. Currently, AP ion sources are commonly available on LC/MS instruments and recently a method was reported for converting an AP-LC/MS ion source to a combination AP-LC/MS:GC/MS source [C.N. McEwen, R.G. McKay, J. Am. Soc. Mass Spectrom. 16 (2005) 1730]. Here, we report the use of atmospheric pressure photoionization (APPI) with GC/MS and compare this to AP chemical ionization (APCI) GC/MS and electron ionization (EI) GC/MS. Using a nitrogen purge gas, we observe excellent chromatographic resolution and abundant molecular M+ and MH+ ions as well as structurally significant fragment ions. Comparison of a 9.8 eV UV lamp with a 10.6 eV lamp, as expected, shows that the higher energy lamp gives more universal ionization and more fragment ions than the lower energy lamp. While there are clear differences in the fragment ions observed by APPI-MS versus EI-MS, there are also similarities. As might be expected from the ionization mechanism, APPI ionization is similar to low energy EI. These odd electron fragment ions are useful in identifying unknown compounds by comparison to mass spectra in computer libraries.

  13. 50 CFR 660.150 - Mothership (MS) Coop Program.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 50 Wildlife and Fisheries 9 2010-10-01 2010-10-01 false Mothership (MS) Coop Program. 660.150... Groundfish-Limited Entry Trawl Fisheries § 660.150 Mothership (MS) Coop Program. (a) General. The MS Coop...)(3), (f)(5), (f)(6), (g)(3), (g)(5), and (g)(6) which are effective immediately. The MS Coop...

  14. 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: This is a Notice of the Presidential declaration of a major disaster for Public Assistance Only for...

  15. 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: This is a Notice of the Presidential declaration of a major disaster for Public Assistance Only for...

  16. 78 FR 12805 - Mississippi Disaster #MS-00064

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-25

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS 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...

  17. 78 FR 3494 - Mississippi Disaster #MS-00063

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-16

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS 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...

  18. 75 FR 79064 - Mississippi Disaster #MS-00042

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-17

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS 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...

  19. 75 FR 29371 - Mississippi Disaster #MS-00037

    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-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...

  20. 75 FR 25304 - Mississippi Disaster #MS-00035

    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-00035 AGENCY: Small Business Administration. ACTION: Notice. SUMMARY: This is a Notice of the Presidential declaration of a major disaster for the State of Mississippi...

  1. 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: This is a Notice of the Presidential declaration of a major disaster for Public Assistance Only for...

  2. 76 FR 27139 - Mississippi Disaster # MS-00045

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-10

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS 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...

  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 is a Notice of the Presidential declaration of a major disaster for Public Assistance Only for...

  4. 76 FR 76801 - Mississippi Disaster #MS-00052

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-08

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION Mississippi Disaster MS-00052 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...

  5. 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: This is a Notice of the Presidential declaration of a major disaster for Public Assistance Only for...

  6. 76 FR 29810 - Mississippi Disaster #MS-00048

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-23

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS 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...

  7. 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: This is a notice of an Administrative declaration of a disaster for the State of Mississippi dated...

  8. 77 FR 55890 - Mississippi Disaster # MS-00059

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-11

    ... From the Federal Register Online via the Government Publishing Office ] SMALL BUSINESS 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...

  9. 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

  10. Atmospheric pressure ionization LC-MS-MS determination of urushiol congeners.

    PubMed

    Draper, William M; Wijekoon, Donald; McKinney, Michael; Behniwal, Paramjit; Perera, S Kusum; Flessel, C Peter

    2002-03-27

    This paper describes atmospheric pressure ionization (API) LC-MS-MS determination of urushiols, 3-n-alkenyl- and -alkyl-substituted catechols responsible for poison oak dermatitis. Urushiol was isolated from Western poison oak according to the method of Elsohly et al. (1) (J. Nat. Prod. 1982, 45, 532-538)-the purified preparation contained C(17)- and C(15)-substituted urushiols with zero, one, two, and three double bonds as determined from GC-MS analysis of trimethylsilyl derivatives. Urushiol mixtures were separated on a C(18) reversed phase HPLC column with a methanol-water gradient with urushiols eluting in 100% methanol. Atmospheric pressure chemical ionization (APCI) produced primarily [M - H](-) and MH(+) molecule ions. Electrospray ionization (ESI) yielded [M - H](-) and adduct ions including [M + Cl](-). Daughter ions of [M - H](-) included quinoid radical anions ([M - H - H(2)](-) and m/z 122(-)) and a benzofuran phenate (m/z 135(-)). A suite of hydrocarbon fragments were produced by collision-induced dissociation of MH(+) directly or via an intermediate [MH - H(2)O](+) daughter ion. Six urushiol congeners, one not previously reported in poison oak, were determined by negative ion API-LC-MS-MS with detection limits of approximately 8 pg/microL (ESI) and approximately 800 pg/microL (APCI). API-LC-MS-MS was used to determine urushiol in surface wipes, air samples, and plant materials. PMID:11902923

  11. Monoacylglycerol Analysis Using MS/MS(ALL) Quadruple Time of Flight Mass Spectrometry.

    PubMed

    Gao, Fei; McDaniel, Justice; Chen, Emily Y; Rockwell, Hannah; Lynes, Matthew D; Tseng, Yu-Hua; Sarangarajan, Rangaprasad; Narain, Niven R; Kiebish, Michael A

    2016-01-01

    Monoacylglycerols (MAGs) are structural and bioactive metabolites critical for biological function. Development of facile tools for measuring MAG are essential to understand its role in different diseases and various pathways. A data-independent acquisition method, MS/MS(ALL), using electrospray ionization (ESI) coupled quadrupole time of flight mass spectrometry (MS), was utilized for the structural identification and quantitative analysis of individual MAG molecular species. Compared with other acylglycerols, diacylglycerols (DAG) and triacylglycerols (TAG), MAG characteristically presented as a dominant protonated ion, [M + H]⁺, and under low collision energy as fatty acid-like fragments due to the neutral loss of the glycerol head group. At low concentrations (<10 pmol/µL), where lipid-lipid interactions are rare, there was a strong linear correlation between ion abundance and MAG concentration. Moreover, using the MS/MS(ALL) method the major MAG species from human plasma and mouse brown and white adipose tissues were quantified in less than 6 min. Collectively, these results demonstrate that MS/MS(ALL) analysis of MAG is an enabling strategy for the direct identification and quantitative analysis of low level MAG species from biological samples with high throughput and sensitivity. PMID:27548241

  12. Global MS-Based Proteomics Drug Profiling.

    PubMed

    Carvalho, Ana Sofia; Matthiesen, Rune

    2016-01-01

    DNA-based technologies such as RNAi, chemical-genetic profiling, or gene expression profiling by DNA microarrays combined with other biochemical methods are established strategies for surveying drug mechanisms. Such approaches can provide mechanistic information on how drugs act and affect cellular pathways. By studying how cancer cells compensate for the drug treatment, novel targets used in a combined treatment can be designed. Furthermore, toxicity effects on cells not targeted can be obtained on a molecular level. For example, drug companies are particularly interested in studying the molecular side effects of drugs in the liver. In addition, experiments with the purpose of elucidating liver toxicity can be studied using samples obtained from animal models exposed to different concentrations of a drug over time. More recently considerable advances in mass spectrometry (MS) technologies and bioinformatics tools allows informative global drug profiling experiments to be performed at a cost comparable to other large-scale technologies such as DNA-based technologies. Moreover, MS-based proteomics provides an additional layer of information on the dynamic regulation of proteins translation and particularly protein degradation. MS-based proteomics approaches combined with other biochemical methods delivers information on regulatory networks, signaling cascades, and metabolic pathways upon drug treatment. Furthermore, MS-based proteomics can provide additional information on single amino acid polymorphisms, protein isoform distribution, posttranslational modifications, and subcellular localization. In this chapter, we will share our experience using MS based proteomics as a pharmacoproteomics strategy to characterize drug mechanisms of action in single drug therapy or in multidrug combination. Finally, the emergence of integrated proteogenomics analysis, such as "The Cancer Genome Atlas" program, opened interesting perspectives to extend this approach to drug target

  13. 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.

  14. Optimal precursor ion selection for LC-MALDI MS/MS

    PubMed Central

    2013-01-01

    Background Liquid chromatography mass spectrometry (LC-MS) maps in shotgun proteomics are often too complex to select every detected peptide signal for fragmentation by tandem mass spectrometry (MS/MS). Standard methods for precursor ion selection, commonly based on data dependent acquisition, select highly abundant peptide signals in each spectrum. However, these approaches produce redundant information and are biased towards high-abundance proteins. Results We present two algorithms for inclusion list creation that formulate precursor ion selection as an optimization problem. Given an LC-MS map, the first approach maximizes the number of selected precursors given constraints such as a limited number of acquisitions per RT fraction. Second, we introduce a protein sequence-based inclusion list that can be used to monitor proteins of interest. Given only the protein sequences, we create an inclusion list that optimally covers the whole protein set. Additionally, we propose an iterative precursor ion selection that aims at reducing the redundancy obtained with data dependent LC-MS/MS. We overcome the risk of erroneous assignments by including methods for retention time and proteotypicity predictions. We show that our method identifies a set of proteins requiring fewer precursors than standard approaches. Thus, it is well suited for precursor ion selection in experiments with limited sample amount or analysis time. Conclusions We present three approaches to precursor ion selection with LC-MALDI MS/MS. Using a well-defined protein standard and a complex human cell lysate, we demonstrate that our methods outperform standard approaches. Our algorithms are implemented as part of OpenMS and are available under http://www.openms.de. PMID:23418672

  15. Lipid dynamics in zebrafish embryonic development observed by DESI-MS imaging and nanoelectrospray-MS.

    PubMed

    Pirro, V; Guffey, S C; Sepúlveda, M S; Mahapatra, C T; Ferreira, C R; Jarmusch, A K; Cooks, R G

    2016-06-01

    The zebrafish Danio rerio is a model vertebrate organism for understanding biological mechanisms. Recent studies have explored using zebrafish as a model for lipid-related diseases, for in vivo fish bioassays, and for embryonic toxicity experiments. Mass spectrometry (MS) and MS imaging are established tools for lipid profiling and spatial mapping of biomolecules and offer rapid, sensitive, and simple analytical protocols for zebrafish analysis. When ambient ionization techniques are used, ions are generated in native environmental conditions, requiring neither sample preparation nor separation of molecules prior to MS. We used two direct MS techniques to describe the dynamics of the lipid profile during zebrafish embryonic development from 0 to 96 hours post-fertilization and to explore these analytical approaches as molecular diagnostic assays. Desorption electrospray ionization (DESI) MS imaging followed by nanoelectrospray (nESI) MS and tandem MS (MS/MS) were used in positive and negative ion modes, allowing the detection of a large variety of phosphatidylglycerols, phosphatidylcholines, phosphatidylinositols, free fatty acids, triacylglycerols, ubiquinone, squalene, and other lipids, and revealed information on the spatial distributions of lipids within the embryo and on lipid molecular structure. Differences were observed in the relative ion abundances of free fatty acids, triacylglycerols, and ubiquinone - essentially localized to the yolk - across developmental stages, whereas no relevant differences were found in the distribution of complex membrane glycerophospholipids, indicating conserved lipid constitution. Embryos exposed to trichloroethylene for 72 hours exhibited an altered lipid profile, indicating the potential utility of this technique for testing the effects of environmental contaminants. PMID:27120110

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  17. MALDI-TOF and nESI Orbitrap MS/MS identify orthogonal parts of the phosphoproteome.

    PubMed

    Ruprecht, Benjamin; Roesli, Christoph; Lemeer, Simone; Kuster, Bernhard

    2016-05-01

    Phosphorylation is a reversible posttranslational protein modification which plays a pivotal role in intracellular signaling. Despite extensive efforts, phosphorylation site mapping of proteomes is still incomplete motivating the exploration of alternative methods that complement existing workflows. In this study, we compared tandem mass spectrometry (MS/MS) on matrix assisted laser desorption/ionization time-of-flight (MALDI-TOF) and nano-electrospray ionization (nESI) Orbitrap instruments with respect to their ability to identify phosphopeptides from complex proteome digests. Phosphopeptides were enriched from tryptic digests of cell lines using Fe-IMAC column chromatography and subjected to LC-MS/MS analysis. We found that the two analytical workflows exhibited considerable orthogonality. For instance, MALDI-TOF MS/MS favored the identification of phosphopeptides encompassing clear motif signatures for acidic residue directed kinases. The extent of orthogonality of the two LC-MS/MS systems was comparable to that of using alternative proteases such as Asp-N, Arg-C, chymotrypsin, Glu-C and Lys-C on just one LC-MS/MS instrument. Notably, MALDI-TOF MS/MS identified an unexpectedly high number and percentage of phosphotyrosine sites (∼20% of all sites), possibly as a direct consequence of more efficient ionization. The data clearly show that LC-MALDI MS/MS can be a useful complement to LC-nESI MS/MS for phosphoproteome mapping and particularly so for acidic and phosphotyrosine containing peptides. PMID:26990019

  18. 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.

  19. 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...

  20. Single hair analysis of small molecules using MALDI-triple quadrupole MS imaging and LC-MS/MS: investigations on opportunities and pitfalls.

    PubMed

    Poetzsch, Michael; Steuer, Andrea E; Roemmelt, Andreas T; Baumgartner, Markus R; Kraemer, Thomas

    2014-12-01

    Single hair analysis normally requires extensive sample preparation microscale protocols including time-consuming steps like segmentation and extraction. Matrix assisted laser desorption and ionization mass spectrometric imaging (MALDI-MSI) was shown to be an alternative tool in single hair analysis, but still, questions remain. Therefore, an investigation of MALDI-MSI in single hair analysis concerning the extraction process, usage of internal standard (IS), and influences on the ionization processes were systematically investigated to enable the reliable application to hair analysis. Furthermore, single dose detection, quantitative correlation to a single hair, and hair strand LC-MS/MS results were performed, and the performance was compared to LC-MS/MS single hair monitoring. The MALDI process was shown to be independent from natural hair color and not influenced by the presence of melanin. Ionization was shown to be reproducible along and in between different hair samples. MALDI image intensities in single hair and hair snippets showed good semiquantitative correlation to zolpidem hair concentrations obtained from validated routine LC-MS/MS methods. MALDI-MSI is superior to LC-MS/MS analysis when a fast, easy, and cheap sample preparation is necessary, whereas LC-MS/MS showed higher sensitivity with the ability of single dose detection for zolpidem. MALDI-MSI and LC-MS/MS segmental single hair analysis showed good correlation, and both are suitable for consumption monitoring of drugs of abuse with a high time resolution. PMID:25289728

  1. 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.

  2. 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

  3. Quantitative analysis of acrylamide labeled serum proteins by LC-MS/MS.

    PubMed

    Faca, Vitor; Coram, Marc; Phanstiel, Doug; Glukhova, Veronika; Zhang, Qing; Fitzgibbon, Matthew; McIntosh, Martin; Hanash, Samir

    2006-08-01

    Isotopic labeling of cysteine residues with acrylamide was previously utilized for relative quantitation of proteins by MALDI-TOF. Here, we explored and compared the application of deuterated and (13)C isotopes of acrylamide for quantitative proteomic analysis using LC-MS/MS and high-resolution FTICR mass spectrometry. The method was applied to human serum samples that were immunodepleted of abundant proteins. Our results show reliable quantitation of proteins across an abundance range that spans 5 orders of magnitude based on ion intensities and known protein concentration in plasma. The use of (13)C isotope of acrylamide had a slightly greater advantage relative to deuterated acrylamide, because of shifts in elution of deuterated acrylamide relative to its corresponding nondeuterated compound by reversed-phase chromatography. Overall, the use of acrylamide for differentially labeling intact proteins in complex mixtures, in combination with LC-MS/MS provides a robust method for quantitative analysis of complex proteomes. PMID:16889424

  4. 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). PMID:26602112

  5. Quantification of phytochelatins in plants by reversed-phase HPLC-ESI-MS-MS.

    PubMed

    El-Zohri, M H A; Cabala, R; Frank, H

    2005-08-01

    An on-line HPLC-ESI-MS-MS method has been developed for determination of glutathione and phytochelatins (PC) in plant tissues. For sample pretreatment, dithiothreitol (DTT) must be added at the very beginning, as an anti-oxidant. Optimization of instrumental conditions i.e. composition of HPLC mobile phase, ionization efficiency of the electrospray interface, and MS-MS detection in the multiple ion-monitoring mode, are the central aspects of this work. A polystyrene-packed column was found to be superior to a standard silica-packed reversed-phase column. A concave quadratic gradient of ammonium formate buffer and acetonitrile was found to be optimum. The limits of quantitation were 0.2 micromol kg(-1) plant tissue for glutathione and PC. The method has been applied to analysis of tissue samples from Vicia faba grown in Cd-containing nutrient solutions. PMID:16001238

  6. Quantification of Free Phenytoin by Liquid Chromatography Tandem Mass Spectrometry (LC/MS/MS).

    PubMed

    Peat, Judy; Frazee, Clint; Garg, Uttam

    2016-01-01

    Phenytoin (diphenylhydantoin) is an anticonvulsant drug that has been used for decades for the treatment of many types of seizures. The drug is highly protein bound and measurement of free-active form of the drug is warranted particularly in patients with conditions that can affect drug protein binding. Here, we describe a LC/MS/MS method for the measurement of free phenytoin. Free drug is separated by ultrafiltration of serum or plasma. Ultrafiltrate is treated with acetonitrile containing internal standard phenytoin d-10 to precipitate proteins. The mixture is centrifuged and supernatant is injected onto LC-MS-MS, and analyzed using multiple reaction monitoring. This method is linear from 0.1 to 4.0 μg/mL and does not demonstrate any significant ion suppression or enhancement. PMID:26660192

  7. Rapid evaluation of 25 key sphingolipids and phosphosphingolipids in human plasma by LC-MS/MS.

    PubMed

    Basit, Abdul; Piomelli, Daniele; Armirotti, Andrea

    2015-07-01

    We report on a new, sensitive, and fast LC-MS/MS method for the simultaneous determination of 25 key sphingolipid components in human plasma, including phosphorylated sphinganine and sphingosine, in a single 9-min run. This method enables an effective and high-throughput coverage of the metabolic changes involving the sphingolipidome during physiological or pathological states. The method is based on liquid-liquid extraction followed by reversed-phase LC-MS/MS. Exogenous odd-chain lipids are used as cost-effective but reliable internal standards. The method was fully validated in surrogate matrix and naive human plasma following FDA guidelines. Sample stability and dilution integrity were also tested and verified. PMID:25749796

  8. MS/MS library facilitated MRM quantification of native peptides prepared by denaturing ultrafiltration

    PubMed Central

    2012-01-01

    Naturally occurring native peptides provide important information about physiological states of an organism and its changes in disease conditions but protocols and methods for assessing their abundance are not well-developed. In this paper, we describe a simple procedure for the quantification of non-tryptic peptides in body fluids. The workflow includes an enrichment step followed by two-dimensional fractionation of native peptides and MS/MS data management facilitating the design and validation of LC- MRM MS assays. The added value of the workflow is demonstrated in the development of a triplex LC-MRM MS assay used for quantification of peptides potentially associated with the progression of liver disease to hepatocellular carcinoma. PMID:22304756

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

    PubMed

    Adamo, Mark E; Gerber, Scott A

    2016-01-01

    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. PMID:27603022

  10. 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.

  11. 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).

  12. STS-35 MS Parker and MS Lounge on OV-102's flight deck review deorbit checklist

    NASA Technical Reports Server (NTRS)

    1990-01-01

    STS-35 Mission Specialist (MS) Robert A.R. Parker (left) and MS John M. Lounge, wearing launch and entry suits (LESs) and launch and entry helmets (LEHs), are in their entry seating positions on the aft flight deck of Columbia, Orbiter Vehicle (OV) 102. The two crewmembers are reviewing deorbit checklists as they prepare for the final stages of their mission and the landing sequence.

  13. Fast and reliable determination of voriconazole in human plasma by LC-APCI-MS/MS.

    PubMed

    Xiong, Xin; Duan, Jingli; Zhai, Suodi; Wang, Lijue; Lan, Xi

    2010-01-01

    A fast and reliable liquid chromatography coupled with atmospheric pressure chemical ionization tandem mass spectrometry (LC-APCI-MS/MS) method was developed and validated for the quantification of voriconazole in human plasma. The proposed method was validated in a linear range of 50-10,000 ng/ml, and the total run time was 1.5 min. This method was successfully used to support routine therapeutic drug monitoring of voriconazole. PMID:20944401

  14. 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.

  15. 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). PMID:26660174

  16. A robust GC-MS/MS method for the determination of chlorothalonil in fruits and vegetables.

    PubMed

    Peruga, A; Barreda, M; Beltrán, J; Hernández, F

    2013-01-01

    Chlorothalonil is a non-systemic fungicide that is easily degraded in contact with plants and soil or even by the effect of light and pH. A method for the determination of chlorothalonil in courgettes, strawberries, oranges, leeks and tomato by solvent extraction followed by GC-MS/MS with a triple quadrupole analyser was developed. The causes of chlorothalonil degradation during sample treatment were studied and minimised. The final method was based on extraction with acetone in the presence of 0.1 M EDTA sodium salt solution, and clean-up by SPE using OASIS HLB cartridges. Isotope-labelled hexachlorobenzene (HCB-(13)C(6)) was added as an internal standard to the SPE extracts before analysis by GC-MS/MS (EI) (QqQ) analysis in order to correct for instrumental deviations. Quantification was performed by matrix-matched standard calibration using relative responses to the internal standard. Two MS/MS transitions were used for mass spectrometric determination of chlorothalonil to ensure reliable quantification and confirmation. The method was validated using blank samples (for all matrices) spiked at two levels. Recoveries between 77% and 110% and an RSD below 20% were obtained for 0.1 and 0.01 mg kg(-1) spiking levels (n = 5). The validated method was applied to treated and untreated samples collected from an experimental field where a chlorothalonil formulated was applied. PMID:23116300

  17. Ultrahigh-Throughput Proteomics Using Fast RPLC Separations with ESI-MS/MS

    SciTech Connect

    Shen, Yufeng; Smith, Richard C.; 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 µm i.d. fused silica capillaries packed with micron-sized C18-bonded porous silica particles and achieved peak capacities of 130-420 for peptides. When these separations were combined with a linear ion trap mass spectrometer, ~1,000 proteins could be identified in 50 minutes based upon the identification of ~4,000 tryptic peptides; ~550 proteins in 20 minutes from ~1,800 peptides; and ~250 proteins in 8 minutes from ~700 peptides for a S. oneidensis tryptic digest. The dynamic range for protein identification was determined to be ~3-4 orders 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) had sufficient quality for identifying peptides. The results indicate that such analyses using very fast (minutes) RPLC separations based on columns packed with micro-sized porous particles are primarily limited by the MS/MS analysis speed.

  18. Investigation of enrofloxacin residues in broiler tissues using ELISA and LC-MS/MS.

    PubMed

    Panzenhagen, Pedro Henrique N; Aguiar, Waldemir S; Gouvêa, Raquel; de Oliveira, Andréa M G; Barreto, Fabiano; Pereira, Virgínia L A; Aquino, Maria Helena C

    2016-04-01

    This study investigated the efficiency of an enrofloxacin ELISA test kit to detect the presence of enrofloxacin residues in broiler tissues compared with LC-MS/MS. Broiler tissues from 72 samples consisting of 60 breast muscle, six pools of livers (500 g each) and six pools of kidneys (500 g each) were obtained from six different slaughterhouses. Breast muscle from 10 carcasses and pools of livers and kidneys from approximately 200 carcasses of the same flock were collected from each slaughterhouse. ELISA and HPLC were used to identify and quantify the contamination of the samples with enrofloxacin. A total of 72% of the analysed samples contained enrofloxacin residues detected by the ELISA and 22.2% were detected by LC-MS/MS. The mean values of enrofloxacin contamination found in chicken breast by ELISA and HPLC were 8.63 and 12.25 μg kg(-1), respectively. None of the samples exceeded the maximum limit of 100 μg kg(-1) by both methods set by the European Union as well as the Brazilian Agriculture Ministry. All positive samples for enrofloxacin residues detected by LC-MS/MS were also positive by ELISA. These data confirm the efficiency of the ELISA test, and suggest its use as a screening method for enrofloxacin residues in poultry tissues due to its quick results, low price and ease of applicability. PMID:26930030

  19. [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. PMID:15678937

  20. 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

  1. 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

    2004-04-01

    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. PMID:15053542

  2. Arsenic speciation in chinese seaweeds using HPLC-ICP-MS and HPLC-ES-MS.

    PubMed

    Van Hulle, Marijn; Zhang, Chao; Zhang, Xinrong; Cornelis, Rita

    2002-05-01

    Three common Chinese edible seaweeds, one brown (Laminaria japonica) and two red (Porphyra crispata and Eucheuma denticulatum), were examined for their total arsenic content. The As species were extracted with yields of 76.4, 69.8 and 25.0%, respectively. Anion-exchange and cation-exchange high-performance liquid chromatography (HPLC) in combination with inductively coupled plasma mass spectrometry (ICP-MS) were used for the separation of the different arsenic species in two of the three seaweed extracts (Laminaria and Porphyra). The main arsenic species in the algal extracts are arseno sugars, although it has been shown that the Laminaria seaweed contains significant amounts of dimethylarsinic acid (DMA). HPLC was coupled with electrospray mass spectrometry (ES-MS) for structural confirmation of the arsenic species. The mass spectrometer settings for the arseno sugars were optimised using standards. The conclusions drawn on the basis of HPLC-ICP-MS were confirmed by the HPLC-ES-MS data. The HPLC-ES-MS method is capable of determining both arseno sugars and DMA in the seaweeds. The unknown compounds seen in the HPLC-ICP-MS chromatogram of Laminaria could not be ascribed to trimethylarsenic oxide or tetramethylarsonium ion. PMID:12081041

  3. Fluxome analysis using GC-MS

    PubMed Central

    Wittmann, Christoph

    2007-01-01

    Fluxome analysis aims at the quantitative analysis of in vivo carbon fluxes in metabolic networks, i. e. intracellular activities of enzymes and pathways. It allows investigating the effects of genetic or environmental modifications and thus precisely provides a global perspective on the integrated genetic and metabolic regulation within the intact metabolic network. The experimental and computational approaches developed in this area have revealed fascinating insights into metabolic properties of various biological systems. Most of the comprehensive approaches for metabolic flux studies today involve isotopic tracer studies and GC-MS for measurement of the labeling pattern of metabolites. Initially developed and applied mainly in the field of biomedicine these GC-MS based metabolic flux approaches have been substantially extended and optimized during recent years and today display a key technology in metabolic physiology and biotechnology. PMID:17286851

  4. 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.

  5. Progressive MS: from pathophysiology to drug discovery.

    PubMed

    Salvetti, Marco; Landsman, Douglas; Schwarz-Lam, Peter; Comi, Giancarlo; Thompson, Alan J; Fox, Robert J

    2015-10-01

    Progressive multiple sclerosis (MS) will be a major area of research interest for years to come. No treatments exist and success in the field will generalise to other neurological conditions where neurodegeneration coexists with neuroinflammation. The issue is complex, and interdisciplinary approaches - uniting scientists with different competences (neurobiology, immunogenetics, etc.) and 'mindsets' (academia and industry) - will be decisive. The International Progressive MS Alliance is catalysing this process through various initiatives, the most recent of which was a meeting where scientists from academia (also outside the MS field) and from industry reviewed data and strategies to determine the next steps towards the translation of current knowledge into effective therapies.Key findings are:(i). Concerted efforts are essential to prioritise pathogenetic mechanisms according to impact on the disease and druggability.(ii). Combination therapies will probably be needed, possibly early in the disease, along with new trial designs and treatment schedules.(iii). Drug screenings are a pragmatic approach hopefully enriched by the use of neural and oligodendrocyte progenitors differentiated from induced pluripotent stem cells (iPSCs).(iv). The field of network biology will increase our ability to predict therapeutic targets.(v). Genome-wide association studies (GWAS) must try to identify variants associated with disease progression. PMID:26362902

  6. 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. PMID:22884787

  7. Expeditious discrimination of four species of the Panax genus using direct infusion-MS/MS combined with multivariate statistical analysis.

    PubMed

    Kim, Shinae; Shin, Byong-Kyu; Lim, Dong Kyu; Yang, Tae-Jin; Lim, Johan; Park, Jeong Hill; Kwon, Sung Won

    2015-10-01

    A practical approach based on direct infusion-MS/MS (DI-MS/MS) was demonstrated for metabolomic classification of four species in the Panax genus. The species Panax ginseng, Panax notoginseng, Panax quinquefolius and Panax vietnamensis were analyzed to develop an efficient tool for authenticating ginseng. Four target ions (m/z 783.5, 945.5, 1107.5 and 1149.2) were selected from LC-MS screening results for DI-MS/MS analysis. The target ions served as classifiers of the four species. As a targeted analysis, DI-MS/MS provided the structural identities of the target ions, clear spectral data and high sensitivity in a shorter time than routine LC-MS analysis. Principal component analysis and partial least squares-discriminant analysis of the DI-MS/MS fingerprinting revealed distinct grouping of the data. The results were validated by cross-validation and a permutation test to examine the utility of the statistical models. The spectral intensities of each species were compared with one another using box plots, which allowed straightforward authentication of the Panax species. The proposed method showed improved efficiency over other current methods for discrimination of large quantities of plant material. Additionally, to the best of our knowledge, this is the first study in which DI-MS/MS has been used to classify plant samples. PMID:26350425

  8. Chemical compositions by using LC-MS/MS and GC-MS and biological activities of Sedum sediforme (Jacq.) Pau.

    PubMed

    Ertaş, Abdulselam; Boğa, Mehmet; Yılmaz, Mustafa Abdullah; Yeşil, Yeter; Haşimi, Nesrin; Kaya, Meryem Şeyda; Temel, Hamdi; Kolak, Ufuk

    2014-05-21

    In this research, the chemical composition and biological activities of various extracts obtained from whole parts of Sedum sediforme (Jacq.) Pau were compared. The amounts of total phenolic and flavonoid components in crude extracts were determined by expression as pyrocatechol and quercetin equivalents, respectively. All of the extracts (petroleum ether, acetone, methanol, and water) obtained from S. sediforme showed strong antioxidant activity in four tested methods. Particularly, the IC50 values of the methanol extract, which was the richest in terms of total phenolic and flavonoid contents, were found to be lower than those of α-tocopherol and BHT in β-carotene bleaching (9.78 ± 0.06 μg/mL), DPPH free radical scavenging (9.07 ± 0.07 μg/mL), and ABTS cation radical scavenging (5.87 ± 0.03 μg/mL) methods. Furthermore, the methanol extract of S. sediforme showed higher inhibition activity than galanthamine against acetyl- and butyryl-cholinesterase enzymes. Also, acetone and methanol extracts exhibited moderate antimicrobial activity against Candida albicans. The main constituents of fatty acid and essential oil were identified as palmitic acid (C16:0) (28.8%) and α-selinene (20.4%), respectively, by GC-MS. In the methanol extract of S. sediforme, quercetin, rutin, naringenin, and protocatechuic, p-coumaric, caffeic, and chlorogenic acids were detected and quantified by LC-MS/MS. Results of the current study showed that the methanol extract of S. sediforme may also be used as a food supplement. PMID:24773044

  9. LC-MS/MS characterization of forced degradation products of zofenopril.

    PubMed

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

    2014-01-01

    A rapid, specific and reliable isocratic LC-MS/MS method has been developed and validated for the identification and characterization of stressed degradation products of Zofenopril. Zofenopril, an anti-hypertensive drug, was subjected to hydrolysis (acidic, alkaline and neutral), oxidation, photolysis and thermal stress, as per ICH-specified conditions. The drug showed extensive degradation under oxidative and base hydrolysis stress conditions. However, it was stable to thermal, acid, neutral and photolysis stress conditions. A total of 6 degradation products were observed and the chromatographic separation of the drug and its degradation products were achieved on Phenomenex (Luna) C18 (250mm×4.6mm, i.d., 5μm) column using 20mM ammonium acetate: 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 zofenopril. PMID:24211724

  10. 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.

  11. Simultaneous Quantification of Sphingolipids in Small Quantities of Liver by LC-MS/MS

    PubMed Central

    Saigusa, Daisuke; Okudaira, Michiyo; Wang, Jiao; Kano, Kuniyuki; Kurano, Makoto; Uranbileg, Baasanjav; Ikeda, Hitoshi; Yatomi, Yutaka; Motohashi, Hozumi; Aoki, Junken

    2014-01-01

    Sph, S1P, and Cer, derived from the membrane sphingolipids, act as intracellular and intercellular mediators, involved in various (path) physiological functions. Accordingly, determining the distributions and concentrations of these sphingolipid mediators in body tissues is an important task. Consequently, a method for determination of sphingolipids in small quantities of tissue is required. Sphingolipids analysis has been dependent on improvements in mass spectrometry (MS) technology. Additionally, decomposition of sphingosine-1-phosphate (S1P) in the tissue samples before preparation for MS has hindered analysis. In the present study, a method for stabilization of liver samples before MS preparation was developed using a heat stabilizer (Stabilizor™ T1). Then, a LC-MS/MS method using a triple-quadrupole mass spectrometer with a C8 column was developed for simultaneous determination of sphingolipids in small quantities of liver specimens. This method showed good separation and validation results. Separation was performed with a gradient elution of solvent A (5 mmol L−1 ammonium formate in water, pH 4.0) and solvent B (5 mmol L−1 ammonium formate in 95% acetonitrile, pH 4.0) at 300 μL min−1. The lower limit of quantification was less than 132 pmol L−1, and this method was accurate (∼13.5%) and precise (∼7.13%) for S1P analysis. The method can be used to show the tissue distribution of sphingolipids. PMID:26819890

  12. 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. PMID:27161445

  13. SweetNET: A Bioinformatics Workflow for Glycopeptide MS/MS Spectral Analysis.

    PubMed

    Nasir, Waqas; Toledo, Alejandro Gomez; Noborn, Fredrik; Nilsson, Jonas; Wang, Mingxun; Bandeira, Nuno; Larson, Göran

    2016-08-01

    Glycoproteomics has rapidly become an independent analytical platform bridging the fields of glycomics and proteomics to address site-specific protein glycosylation and its impact in biology. Current glycopeptide characterization relies on time-consuming manual interpretations and demands high levels of personal expertise. Efficient data interpretation constitutes one of the major challenges to be overcome before true high-throughput glycopeptide analysis can be achieved. The development of new glyco-related bioinformatics tools is thus of crucial importance to fulfill this goal. Here we present SweetNET: a data-oriented bioinformatics workflow for efficient analysis of hundreds of thousands of glycopeptide MS/MS-spectra. We have analyzed MS data sets from two separate glycopeptide enrichment protocols targeting sialylated glycopeptides and chondroitin sulfate linkage region glycopeptides, respectively. Molecular networking was performed to organize the glycopeptide MS/MS data based on spectral similarities. The combination of spectral clustering, oxonium ion intensity profiles, and precursor ion m/z shift distributions provided typical signatures for the initial assignment of different N-, O- and CS-glycopeptide classes and their respective glycoforms. These signatures were further used to guide database searches leading to the identification and validation of a large number of glycopeptide variants including novel deoxyhexose (fucose) modifications in the linkage region of chondroitin sulfate proteoglycans. PMID:27399812

  14. 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

    2016-09-01

    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. PMID:27376459

  15. 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

  16. 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

  17. 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

  18. 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

  19. 50 CFR 660.150 - Mothership (MS) Coop Program.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... provisions of this section. Pursuant to 15 CFR part 904, each MS coop, member permit owner, and owner and... section of the Pacific Coast groundfish regulations. Each year a vessel registered to an MS/CV-endorsed... non-coop fishery, the vessel is registered to an MS/CV-endorsed limited entry permit. (3) The...

  20. Metabolite identification and quantitation in LC-MS/MS-based metabolomics

    PubMed Central

    Xiao, Jun Feng; Zhou, Bin; Ressom, Habtom W.

    2011-01-01

    Metabolomics aims at detection and quantitation of all metabolites in biological samples. The presence of metabolites with a wide variety of physicochemical properties and different levels of abundance challenges existing analytical platforms used for identification and quantitation of metabolites. Significant efforts have been made to improve analytical and computational methods for metabolomics studies. This review focuses on the use of liquid chromatography with tandem mass spectrometry (LC-MS/MS) for quantitative and qualitative metabolomics studies. It illustrates recent developments in computational methods for metabolite identification, including ion annotation, spectral interpretation and spectral matching. We also review selected reaction monitoring and high-resolution MS for metabolite quantitation. We discuss current challenges in metabolite identification and quantitation as well as potential solutions. PMID:22345829

  1. Development and clinical application of an LC-MS-MS method for mescaline in urine.

    PubMed

    Björnstad, Kristian; Helander, Anders; Beck, Olof

    2008-04-01

    Mescaline (3,4,5-trimethoxyphenylethylamine) is an hallucinogenic psychoactive substance present in several species of cacti. Mescaline has a documented use dating back 5700 years. In more recent years, the interest in hallucinogenic designer drugs such as ecstasy has also triggered interest in the naturally occurring mescaline. This study was undertaken to develop a liquid chromatography-tandem mass spectrometry (LC-MS-MS) method for the screening and confirmation of mescaline in human urine samples and to apply this method to routine testing in patient samples. For the screening procedure, chromatographic separation was achieved on a 5-microm HyPURITY C(18) column, using a methanol gradient in ammonium acetate buffer. The MS-MS analysis was performed using selected reaction monitoring; the transitions monitored were m/z 212.3 --> m/z 180.3 for mescaline and m/z 221.3 --> m/z 186.3 for the deuterated internal standard (mescaline-d(9)). The detection limit for mescaline in urine matrix was 3-5 microg/L, the upper limit of quantification was 10,000 microg/L, and the total coefficient of variation for spiked samples containing 10 to 1025 microg/L was < 8.5%. The confirmation procedure included a sample clean-up by solid-phase extraction on a C(18) cartridge, and one extra transition for mescaline (m/z 212.3 --> m/z 195.2) was monitored. The LC-MS-MS method was found to be sensitive and specific for the routine detection of mescaline in urine. Among 462 urine samples collected from young people with alcohol or drug problems, 32% were positive for illicit drugs, but none for mescaline. PMID:18397574

  2. Evaluation of tamoxifen and metabolites by LC-MS/MS and HPLC methods.

    PubMed

    Heath, D D; Flat, S W; Wu, A H B; Pruitt, M A; Rock, C L

    2014-01-01

    Epidemiological and laboratory evidence suggests that quantification of serum or plasma levels of tamoxifen and its metabolites, 4-hydroxy-N-desmethyl-tamoxifen (endoxifen), Z-4-hydroxytamoxifen (4HT), N-desmethyl-tamoxifen (ND-tam), is a clinically useful tool in the assessment and monitoring of breast cancer status in patients taking adjuvant tamoxifen. A liquid chromatographic mass spectrometric method (LC-MS/MS) was used to measure the blood levels of tamoxifen and its metabolites. This fully automated analytical method is specific, accurate and sensitive. The LC-MS/MS automated technique has now become a widely accepted reference method. This study analysed a randomly selected batch of blood samples from participants enrolled in a breast cancer study to compare results from this reference method in 40 samples with those obtained from a recently developed high-performance liquid chromatography (HPLC) method with fluorescence detection. The mean (SD) concentrations for the LC-MS/MS method (endoxifen 12.6 [7.5] ng/mL, tamoxifen 105 [44] ng/mL, 4-HT 1.9 [1.0] ng/mL, ND-tam 181 [69] ng/mL) and the HPLC method (endoxifen 13.1 [7.8] ng/mL, tamoxifen 108 [55] ng/mL, 4-HT 1.8 [0.8] ng/mL, ND-tam 184 [81] ng/mL) did not show any significant differences. The results confirm that the HPLC method offers an accurate and comparable alternative for the quantification of tamoxifen and tamoxifen metabolites. PMID:24693573

  3. 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). PMID:26255955

  4. 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. PMID:26901474

  5. [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. PMID:27405171

  6. 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. PMID:26302964

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

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  8. Determination of daumone in mouse plasma by HPLC/MS-MS.

    PubMed

    Noh, Keumhan; Park, Jong Hee; Kim, Minkyu; Jung, Mankil; Lee, Hwa Jeong; Kwon, Kwang-il; Kang, Wonku; Ha, Hunjoo

    2012-02-01

    Daumone, a pheromone secreted by Caenorhabditis elegans, is an essential regulator of chemosensory processes in development and aging. A quantification method using HPLC/MS-MS was developed for the determination of daumone in mouse plasma. After simple protein precipitation with acetonitrile including methaqualone (an internal standard), the analytes were chromatographed on a reversed-phase column and detected by liquid chromatography/tandem mass spectrometry with electrospray ionization. The accuracy and precision of the assay were in accordance with FDA regulations for validation of bioanalytical methods. This method was applied to measure the plasma daumone concentrations following a 5-week repeated oral administration of daumone in mice. PMID:21594879

  9. Isoform analysis of LC-MS/MS data from multidimensional fractionation of the serum proteome.

    PubMed

    Krasnoselsky, Alexei L; Faca, Vitor M; Pitteri, Sharon J; Zhang, Qing; Hanash, Samir M

    2008-06-01

    We developed a visualization approach for the identification of protein isoforms, precursor/mature protein combinations, and fragments from LC-MS/MS analysis of multidimensional fractionation of serum and plasma proteins. We also describe a pattern recognition algorithm to automatically detect and flag potentially heterogeneous species of proteins in proteomic experiments that involve extensive fractionation and result in a large number of identified serum or plasma proteins in an experiment. Examples are given of proteins with known isoforms that validate our approach and present a subset of precursor/mature protein pairs that were detected with this approach. Potential applications include identification of differentially expressed isoforms in disease states. PMID:18419151

  10. Antibody-free workflows for protein quantification by LC-MS/MS.

    PubMed

    Wilffert, Daniel; Bischoff, Rainer; van de Merbel, Nico C

    2015-01-01

    Antibody-free approaches for quantitative LC-MS/MS-based protein bioanalysis are reviewed and critically evaluated, and compared with the more widely used immunoaffinity-based approaches. Antibody-free workflows will be divided into four groups and discussed in the following order: direct analysis of signature peptides after proteolytic digestion; enrichment of target proteins and signature peptides by fractionated protein precipitation; enrichment of target proteins and signature peptides by reversed-phase and ion-exchange solid-phase extraction; and enrichment of target proteins and signature peptides by (antibody-free) affinity-solid-phase extraction. PMID:25871591

  11. 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.

  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. 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.

  14. 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.

  15. MALDI-TOF MS in Prenatal Genomics

    PubMed Central

    Zhong, Xiao Yan; Holzgreve, Wolfgang

    2009-01-01

    Summary Prenatal diagnosis aims either to provide the reassurance to the couples at risk of having an affected child by timely appropriate therapy or to give the parents a chance to decide the fate of the unborn babies with health problems. Invasive prenatal diagnosis (IPD) is accurate, however, carrying a risk of miscarriage. Non-invasive prenatal diagnosis (NIPD) has been developed based on the existing of fetal genetic materials in maternal circulation; however, a minority fetal DNA in majority maternal background DNA hinders the detections of fetal traits. Different protocols and assays, such as homogenous MassEXTEND (hME), single allele base extension reaction (SABER), precise measuring copy number variation of each allele, and quantitative methylation and expression analysis using the high-throughput sensitive matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS), allow NIPD for single gene disorders, fetal blood group genotyping and fetal aneuploidies as well as the development of fetal gender-independent biomarkers in maternal circulation for management of pathological pregnancies. In this review, we summarise the use of MALDI-TOF MS in prenatal genomics. PMID:21049077

  16. Comparison of Traditional 2-AB Fluorescence LC-MS/MS and Automated LC-MS for the Comparative Glycan Analysis of Monoclonal Antibodies.

    PubMed

    Schiel, John E; Rogstad, Sarah M; Boyne, Michael T

    2015-08-01

    Monoclonal antibody therapeutics are a heterogeneous mixture of glycoforms. Multiple methods exist for defining the glycan composition and relative abundance of species present. In the current report, two MS-based methods were compared for their ability to both identify glycans and monitor differences in the glycoprofile. Gross changes in the glycoprofile can be identified either by visual inspection of fluorescence profiles and correlated to glycan identities when coupled with online MS/MS (LC-F-MS/MS) or through extracted ion chromatograms using LC-MS. In the present study, both an LC-F-MS/MS method and an automated LC-MS label free approach were able to identify minor differences in low abundance glycoforms, and data indicate a disparity in glycosylation between the analyzed batches of US and foreign-sourced mAb X. Thus, either method may be useful in characterizing monoclonal antibody therapeutics products and could serve as a potential screening test for understanding process, comparability, similarity, and possibly detecting counterfeit agents. PMID:26053232

  17. 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

    2016-08-01

    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. PMID:27267063

  18. Male-sterile maize plants produced by targeted mutagenesis of the cytochrome P450-like gene (MS26) using a re-designed I-CreI homing endonuclease.

    PubMed

    Djukanovic, Vesna; Smith, Jeff; Lowe, Keith; Yang, Meizhu; Gao, Huirong; Jones, Spencer; Nicholson, Michael G; West, Ande; Lape, Janel; Bidney, Dennis; Carl Falco, Saverio; Jantz, Derek; Alexander Lyznik, Leszek

    2013-12-01

    The I-CreI homing endonuclease from Chlamydomonas reinhardti has been used as a molecular tool for creating DNA double-strand breaks and enhancing DNA recombination reactions in maize cells. The DNA-binding properties of this protein were re-designed to recognize a 22 bp target sequence in the 5th exon of MS26, a maize fertility gene. Three versions of a single-chain endonuclease, called Ems26, Ems26+ and Ems26++, cleaved their intended DNA site within the context of a reporter assay in a mammalian cell line. When the Ems26++ version was delivered to maize Black Mexican Sweet cells by Agrobacterium-mediated transformation, the cleavage resulted in mutations at a co-delivered extra-chromosomal ms26-site in up to 8.9% of the recovered clones. Delivery of the same version of Ems26 to immature embryos resulted in mutations at the predicted genomic ms26-site in 5.8% of transgenic T(0) plants. This targeted mutagenesis procedure yielded small deletions and insertions at the Ems26 target site consistent with products of double-strand break repair generated by non-homologous end joining. One of 21 mutagenized T(0) plants carried two mutated alleles of the MS26 gene. As expected, the bi-allelic mutant T(0) plant and the T(1) progeny homozygous for the ms26 mutant alleles were male-sterile. This paper described the second maize chromosomal locus (liguless-1 being the first one) mutagenized by a re-designed I-CreI-based endonuclease, demonstrating the general utility of these molecules for targeted mutagenesis in plants. PMID:24112765

  19. Anisotropy of Magnetic Suscetibility of the Aquidauana Formation (PARANÁ Basin): Preliminary Results

    NASA Astrophysics Data System (ADS)

    Raposo, M. B.; Paranhos, A.

    2013-12-01

    The magnetic studies were performed on sites of reddish-brown sandstones, siltites, and mudstones, which crop out mainly in Mato Grosso do Sul State. Magnetic fabrics were determined on oriented cylindrical specimens (2.54 cm x 2.2 cm) using anisotropy of low-field magnetic susceptibility (AMS). Considering the eingenvector orientations, the sites usually gave good results. The analysis at the individual-site scale defines two AMS fabric types. The first type shows Kmin perpendicular to the bedding plane, while Kmax and Kint are scattered within the bedding plane itself. This fabric is usually interpreted as primary (sedimentary-compactional), typical of undeformed sediments and is dominant among the sites. The second type shows good clustering of the AMS principal axes with Kmin still either perpendicular or sub-perpendicular to the bedding plane. This fabric type could be interpreted as a combination of sedimentary-compactional and tectonic contributions if some strain markers or evidence for tectonic deformation had been found in the studied area. However, the tight Kmax grouping in this fabric type could be explained by the action of currents since they cause Kmax to be aligned sub-parallel to the paleocurrent direction.

  20. 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. PMID:22551636

  1. 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. PMID:18257525

  2. Screening and quantitative determination of drugs of abuse in diluted urine by UPLC-MS/MS.

    PubMed

    Hegstad, Solfrid; Hermansson, Sigurd; Betnér, Ingvar; Spigset, Olav; Falch, Berit Margrethe Hasle

    2014-02-01

    The purpose of this work was to develop and evaluate a fast, robust and specific UPLC-MS/MS screening platform for the determination and quantification of a variety of commonly used drugs of abuse in urine, i.e. a high-throughput quantitative analysis. Substances in the drug classes opioids, central nervous system stimulants and benzodiazepines and related agents were included in addition to cannabis and pregabalin, a total of 35 different analytes. Based on the concentrations and the physico-chemical properties of the substances, three UPLC-MS/MS methods were developed in parallel. Prior to analysis, sample preparation consisted of two different simple dilutions with 60 and 100 μL urine, respectively, using a Tecan Freedom Evo pipetting robot platform. A Waters Xevo TQ-S tandem quadrupole mass spectrometer coupled to a Waters I-class UPLC was used for quantitative analysis of one quantitative and one qualifying MRM transition for each analyte, except for tramadol for which the metabolite O-desmethyl-tramadol was included in the MRM method to confirm tramadol identity. Deuterated analogs were included as internal standards. The between-assay relative standard deviations varied from 2% to 11% and the limits of quantification were in the range 1-200 ng/mL for the various analytes. After development and initial testing, the method has been successfully implemented and routinely used at our hospital for quantitative screening of drugs of abuse in more than 35,000 urinary samples. PMID:24413020

  3. Quantitation of Tenofovir and Emtricitabine in Dried Blood Spots (DBS) with LC-MS/MS

    PubMed Central

    Zheng, Jia-Hua; Guida, Louis A; Rower, Caitlin; Castillo-Mancilla, Jose; Meditz, Amie; Klein, Brandon; Kerr, Becky Jo; Langness, Jacob; Bushman, Lane; Kiser, Jennifer; Anderson, Peter L.

    2013-01-01

    A reversed-phase high performance liquid chromatographic (LC), tandem mass spectrometry (MS/MS) assay for the determination of tenofovir (TFV) and emtricitabine (FTC) in dried blood spots (DBS) from human whole blood was developed and validated. Whole blood samples were spotted, dried, and a 3mm punch was extracted with methanol for analysis by LC-MS/MS utilizing stable isotope labeled internal standards. The assay was validated over the range of 2.5ng/mL to 1,000ng/mL for TFV and 2.5ng/mL to 5,000ng/mL for FTC. The method was accurate (within ± 15% of control) and precise (coefficient of variation ≤ 15%) for hematocrit concentrations ranging from 25% to 76%; using edge punches versus center punches; and spot volumes of 10µL to 50µL. Analytes were stable for five freeze/thaw cycles and up to 6 days at room temperature, whereas long-term storage required −20°C or −80°C. Comparison of TFV and FTC in DBS versus plasma yielded r2 ≥ 0.96, indicating that DBS can be used as a plasma alternative for pharmacokinetic analyses in vivo. PMID:24055850

  4. 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. PMID:23817171

  5. Annotation of Different Dehydrocatechin Oligomers by MS/MS and Their Occurrence in Black Tea.

    PubMed

    Verloop, Annewieke J W; Gruppen, Harry; Vincken, Jean-Paul

    2016-08-01

    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. PMID:27380714

  6. HILIC-MS for metabolomics: An attractive and complementary approach to RPLC-MS.

    PubMed

    Tang, Dao-Quan; Zou, Ll; Yin, Xiao-Xing; Ong, Choon Nam

    2016-09-01

    Hydrophilic interaction chromatography (HILIC) is an emerging separation mode of liquid chromatography (LC). Using highly hydrophilic stationary phases capable of retaining polar/ionic metabolites, and accompany with high organic content mobile phase that offer readily compatibility with mass spectrometry (MS) has made HILIC an attractive complementary tool to the widely used reverse-phase (RP) chromatographic separations in metabolomic studies. The combination of HILIC and RPLC coupled with an MS detector expands the number of detected analytes and provides more comprehensive metabolite coverage than use of only RP chromatography. This review describes the recent applications of HILIC-MS/MS in metabolomic studies, ranging from amino acids, lipids, nucleotides, organic acids, pharmaceuticals, and metabolites of specific nature. The biological systems investigated include microbials, cultured cell line, plants, herbal medicine, urine, and serum as well as tissues from animals and humans. Owing to its unique capability to measure more-polar biomolecules, the HILIC separation technique would no doubt enhance the comprehensiveness of metabolite detection, and add significant value for metabolomic investigations. © 2014 Wiley Periodicals, Inc. Mass Spec Rev 35:574-600, 2016. PMID:25284160

  7. 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. PMID:23799268

  8. Analysis of hydrocarbon in auto emissions by APCI/MS/MS with an RF plasma source

    SciTech Connect

    Zhao, J.J.; Lubman, D.M.; Dearth, M.A.; Korniski, T.J.

    1994-12-31

    Measurement of hydrocarbons in automotive exhausts has been a major task for automotive industries and environmental agencies. Since hydrocarbons emitted from auto exhausts are air toxic, analysis of hydrocarbons in auto emissions is essential to meet the EPA standards, and is important for studying factors affecting combustion and catalysis efficiencies of the vehicle. Current standards require methods capable of on-line real time measurements of individual hydrocarbons at low concentrations. Due to its high sensitivity, fast analysis and MS/MS capability, tandem mass spectrometry with a triple quadrupole using an APCI source has become the method of choice. APCI/MS/MS analysis of individual aromatic compounds with a corona discharge ion source has been reported by Dearth et al. The RF plasma, a newly developed low power high discharge current APCI source, has the capability of producing larger linear dynamic range and higher sensitivity, and may be more suitable for the analysis of mixtures. RF plasma detection of hydrocarbons (both aromatic and aliphatic) has shown excellent soft ionization and sensitivity. As an application, the authors used this new method to analyze hydrocarbons in an auto emission sample.

  9. A LC-MS-MS method to detect recombinant bovine somatotropin misuse in buffalos.

    PubMed

    Castigliego, Lorenzo; Armani, Andrea; Grifoni, Goffredo; Mazzi, Marco; Boselli, Carlo; Guidi, Alessandra; Donzelli, Riccardo; Saba, Alessandro

    2016-07-01

    Recombinant bovine somatotropin (rbST) is a peptide hormone used to increase milk yield in cows and buffalos. In Europe, its use has been banned. However, rbST is sometimes illegally included in zootechnical practices for profit purposes, undermining the fair trade and the law prescriptions. For this reason, efficient and reliable analytical techniques are required to contrast rbST misuse. A few LC-MS-MS methods have been developed to detect, in cow serum, methyonil-rbST, one of the two main rbST forms available on the market. The other form, which is widespread, is identical to the most abundant variant of bovine somatotropin (bST) and differs from the buffalo somatotropin for one amino acid in the N-terminus. For this reason, it is technically possible to distinguish both rbST forms in serum of buffalos. In this work, we describe a novel LC-MS-MS-based method, capable to quantify, with a high sensitivity and selectivity, the methyonil-rbST and the other bST-identical recombinant form in buffalo serum, previously purified using a solid-phase extraction procedure. The method was internally validated and used to analyse 152 serum samples, collected from eight buffalos administered with rbST for a period of 3 months, according to conventional protocols. The obtained results confirmed the suitability of the method in the detection of illegal hormonal treatments. Graphical abstract ᅟ. PMID:27146507

  10. 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

  11. 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

  12. 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. PMID:26871280

  13. 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. PMID:27185818

  14. 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.

  15. LC/MS/MS as a potential method for characterizing bacterial contamination during spacecraft assembly

    NASA Technical Reports Server (NTRS)

    Cornett, L.; Basic, C.; Schubert, W.; Lee, T.

    2000-01-01

    Exploration of outer bodies of interest to life's origins requires stringent measures to prevent contamination of these bodies with Earth life forms. Procedures are taken to vigorously clean spacecraft before launch. We are exploring MS to measure contamination during spacecraft assembly.

  16. 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. PMID:27442797

  17. Quantitation of the anaesthetic xylazine in ovine plasma by LC-MS/MS.

    PubMed

    Doran, Gregory S; Bradbury, Leah A

    2015-08-01

    Removal of the wool-bearing skin around a young lamb's rump (mulesing) provides long term health benefits for the animal, and the use of a sedative and analgesic agent such as xylazine may assist with pain relief to reduce discomfort and stress. Sensitive analytical methods are essential for monitoring pharmaceuticals and their metabolites in animals destined for human consumption. The following work reports a method that is 200 times more sensitive for xylazine detection than previously published methods, with lower limits of quantitation for xylazine and its primary metabolite in animals of 0.5pg and 2pg on-column, respectively. The use of a square wave solvent gradient immediately prior to analyte elution resulted in larger MS/MS peaks and a reduction in baseline noise, allowing reliable detection of lower analyte concentrations. The method uses as little as 1mL of plasma which allows replication within a sample if required, and requires simple sample preparation, minimising the introduction of matrix components into the MS/MS. PMID:26094209

  18. 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

  19. 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

    2016-04-01

    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

  20. Metabolic profile of glyburide in human liver microsomes using LC-DAD-Q-TRAP-MS/MS.

    PubMed

    Ravindran, Selvan; Basu, Sudipta; Gorti, Santosh Kapil Kumar; Surve, Prashant; Sloka, Navya

    2013-05-01

    The sulfonylurea urea drug glyburide (glibenclamide) is widely used for the treatment of diabetes milletus and gestational diabetes. In previous studies monohydroxylated metabolites were identified and characterized for glyburide in different species, but the metabolite owing to the loss of cyclohexyl ring was identified only in mouse. Glyburide upon incubation with hepatic microsomes resulted in 10 metabolites for human. The current study identifies new metabolites of glyburide along with the hydroxylated metabolites that were reported earlier. The newly identified drug metabolites are dihydroxylated metabolites, a metabolite owing to the loss of cyclohexyl ring and one owing to hydroxylation with dehydrogenation. Among the 10 identified metabolites, there were six monohydroxylated metabolites, one dihydroxylated metabolite, two metabolites owing to hydroxylation and dehydrogenation, and one metabolite owing to the loss of cyclohexyl ring. New metabolites of glyburide were identified and characterized using liquid chromatography-diode array detector-quadruple-ion trap-mass spectrometry/mass spectrometry (LC-DAD-Q-TRAP-MS/MS). An enhanced mass scan-enhanced product ion scan with information-dependent acquisition mode in a Q-TRAP-MS/MS system was used to characterize the metabolites. Liquid chromatography with diode array detection was used as a complimentary technique to confirm and identify the metabolites. Metabolites formed in higher amounts were detected in both diode array detection and mass spectrometry detection. PMID:23070832

  1. Analysis of vitamin E metabolites including carboxychromanols and sulfated derivatives using LC/MS/MS.

    PubMed

    Jiang, Qing; Xu, Tianlin; Huang, Jianjie; Jannasch, Amber S; Cooper, Bruce; Yang, Chao

    2015-11-01

    Tocopherols and tocotrienols are metabolized via hydroxylation and oxidation of their hydrophobic side chain to generate 13'-hydroxychromanols (13'-OHs) and various carboxychromanols, which can be further metabolized by conjugation including sulfation. Recent studies indicate that long-chain carboxychromanols, especially 13'-carboxychromanol (13'-COOH), appear to be more bioactive than tocopherols in anti-inflammatory and anticancer actions. To understand the potential contribution of metabolites to vitamin E-mediated effects, an accurate assay is needed to evaluate bioavailability of these metabolites. Here we describe an LC/MS/MS assay for quantifying vitamin E metabolites using negative polarity ESI. This assay includes a reliable sample extraction procedure with efficacy of ≥ 89% and interday/intraday variation of 3-11% for major metabolites. To ensure accurate quantification, short-chain, long-chain, and sulfated carboxychromanols are included as external/internal standards. Using this assay, we observed that sulfated carboxychromanols are the primary metabolites in the plasma of rodents fed with γ-tocopherol or δ-tocopherol. Although plasma levels of 13'-COOHs and 13'-OHs are low, high concentrations of these compounds are found in feces. Our study demonstrates an LC/MS/MS assay for quantitation of sulfated and unconjugated vitamin E metabolites, and this assay will be useful for evaluating the role of these metabolites in vivo. PMID:26351363

  2. Determination of pinostrobin in rat plasma by LC-MS/MS: application to pharmacokinetics.

    PubMed

    Hua, Xin; Fu, Yu-Jie; Zu, Yuan-Gang; Zhang, Lin; Wang, Wei; Luo, Meng

    2011-12-01

    A rapid and sensitive method for the determination of pinostrobin in rat plasma was developed using liquid chromatography tandem mass spectrometry (LC-MS/MS) for the first time. Isoliquiritigenin was used as an internal standard in rat plasma. Chromatographic separation was performed on an HiQ Sil C(18) column with isocratic elution at a flow rate of 1mL/min. The mobile phase consisted of water and methanol (9:91, v/v) containing 0.1% formic acid. The quantification limit was 10ng/mL within a linear range of 10-1000ng/mL (R=0.9984). The intra- and inter-day assay precision ranged from 3.8-5.3% to 3.2-5.2%, respectively, and the intra- and inter-day assay accuracy was between 93.2-95.1% and 95.5-104.3%, respectively. Our results indicated that the LC-MS/MS method is effective for pharmacokinetic study of pinostrobin in rat plasma. PMID:21840667

  3. 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. PMID:24633566

  4. Determination of N-nitrosodiethanolamine in cosmetic products by LC-MS-MS.

    PubMed

    Schothorst, R C; Somers, H H J

    2005-02-01

    We have developed and validated in-house a liquid chromatography and mass spectrometry (LC-MS-MS) method for determination of N-nitrosodiethanolamine (NDELA) in cosmetics. The sample is diluted with water and then a C18 clean-up is performed. The average recovery of NDELA is 88.3%, range 48.3-112.7%, and the limit of detection is 22.8 microg kg-1. The repeatability is 7.6%, and the intermediate precision is 8.7%. Surveys were carried out in the Netherlands in September and October 2002 to determine the quantities of NDELA in cosmetics marketed in the Netherlands. The LC-MS-MS method was used to determine the NDELA content of 140 cosmetic products including shower gels, hair oils, shampoos and conditioners, cream and foam baths, mud baths, scrubs, creme and other soaps, and body washes. NDELA at levels ranging from 23 to 992 microg kg-1 was found in 35 cosmetic products. PMID:15668809

  5. Integration of Molecular Networking and In-Silico MS/MS Fragmentation for Natural Products Dereplication.

    PubMed

    Allard, Pierre-Marie; Péresse, Tiphaine; Bisson, Jonathan; Gindro, Katia; Marcourt, Laurence; Pham, Van Cuong; Roussi, Fanny; Litaudon, Marc; Wolfender, Jean-Luc

    2016-03-15

    Dereplication represents a key step for rapidly identifying known secondary metabolites in complex biological matrices. In this context, liquid-chromatography coupled to high resolution mass spectrometry (LC-HRMS) is increasingly used and, via untargeted data-dependent MS/MS experiments, massive amounts of detailed information on the chemical composition of crude extracts can be generated. An efficient exploitation of such data sets requires automated data treatment and access to dedicated fragmentation databases. Various novel bioinformatics approaches such as molecular networking (MN) and in-silico fragmentation tools have emerged recently and provide new perspective for early metabolite identification in natural products (NPs) research. Here we propose an innovative dereplication strategy based on the combination of MN with an extensive in-silico MS/MS fragmentation database of NPs. Using two case studies, we demonstrate that this combined approach offers a powerful tool to navigate through the chemistry of complex NPs extracts, dereplicate metabolites, and annotate analogues of database entries. PMID:26882108

  6. Characterization and LC-MS/MS based quantification of hydroxylated fullerenes

    PubMed Central

    Chao, Tzu-Chiao; Song, Guixue; Hansmeier, Nicole; Westerhoff, Paul; Herckes, Pierre; Halden, Rolf U.

    2011-01-01

    Highly water-soluble hydroxylated fullerene derivatives are being investigated for a wide range of commercial products as well as for potential cytotoxicity. However, no analytical methods are currently available for their quantification at sub-ppm concentrations in environmental matrices. Here, we report on the development and comparison of liquid chromatography-ultra violet/visible spectroscopy (LC-UV/vis) and mass spectrometry (LC-MS) based detection and quantification methods for a commercial fullerols. We achieved good separation efficiency using an amide-type hydrophilic interaction liquid chromatography (HILIC) column (plate number >2000) under isocratic conditions with 90% acetonitrile as the mobile phase. The method detection limits (MDLs) ranged from 42.8 ng/mL (UV detection) to 0.19 pg/mL (using MS with multiple reaction monitoring, MRM). Other MS measurement modes achieved MDLs of 125 pg/mL (single quad scan, Q1) and 1.5 pg/mL (multiple ion monitoring, MI). Each detection method exhibited a good linear response over several orders of magnitude. Moreover, we tested the robustness of these methods in the presence of Suvanee River fulvic acids (SRFA) as an example of organic matter commonly found in environmental water samples. While SRFA significantly interfered with UV- and Q1-based quantifications, the interference was relatively low using MI or MRM (relative error in presence of SRFA: 8.6% and 2.5%, respectively). This first report of a robust MS-based quantification method for modified fullerenes dissolved in water suggests the feasibility of implementing MS techniques more broadly for identification and quantification of fullerols and other water-soluble fullerene derivatives in environmental samples. PMID:21294534

  7. Quantitative LC-MS/MS Glycomic Analysis of Biological Samples Using AminoxyTMT.

    PubMed

    Zhou, Shiyue; Hu, Yunli; Veillon, Lucas; Snovida, Sergei I; Rogers, John C; Saba, Julian; Mechref, Yehia

    2016-08-01

    Protein glycosylation plays an important role in various biological processes, such as modification of protein function, regulation of protein-protein interactions, and control of turnover rates of proteins. Moreover, glycans have been considered as potential biomarkers for many mammalian diseases and development of aberrant glycosylation profiles is an important indicator of the pathology of a disease or cancer. Hence, quantitation is an important aspect of a comprehensive glycomics study. Although numerous MS-based quantitation strategies have been developed in the past several decades, some issues affecting sensitivity and accuracy of quantitation still exist, and the development of more effective quantitation strategies is still required. Aminoxy tandem mass tag (aminoxyTMT) reagents are recently commercialized isobaric tags which enable relative quantitation of up to six different glycan samples simultaneously. In this study, liquid chromatography and mass spectrometry conditions have been optimized to achieve reliable LC-MS/MS quantitative glycomic analysis using aminoxyTMT reagents. Samples were resuspended in 0.2 M sodium chloride solution to promote the formation of sodium adduct precursor ions, which leads to higher MS/MS reporter ion yields. This method was first evaluated with glycans from model glycoproteins and pooled human blood serum samples. The observed variation of reporter ion ratios was generally less than 10% relative to the theoretical ratio. Even for the highly complex minor N-glycans, the variation was still below 15%. This strategy was further applied to the glycomic profiling of N-glycans released from blood serum samples of patients with different esophageal diseases. Our results demonstrate the benefits of utilizing aminoxyTMT reagents for reliable quantitation of biological glycomic samples. PMID:27377957

  8. Lung Cancer Serum Biomarker Discovery Using Label Free LC-MS/MS

    PubMed Central

    Zeng, Xuemei; Hood, Brian L.; Zhao, Ting; Conrads, Thomas P.; Sun, Mai; Gopalakrishnan, Vanathi; Grover, Himanshu; Day, Roger S.; Weissfeld, Joel L.; Wilson, David O.; Siegfried, Jill M.; Bigbee, William L.

    2011-01-01

    Introduction Lung cancer remains the leading cause of cancer-related death with poor survival due to the late stage at which lung cancer is typically diagnosed. Given the clinical burden from lung cancer, and the relatively favorable survival associated with early stage lung cancer, biomarkers for early detection of lung cancer are of important potential clinical benefit. Methods We performed a global lung cancer serum biomarker discovery study using liquid chromatography-tandem mass spectrometry (LC-MS/MS) in a set of pooled non-small cell lung cancer (NSCLC) case sera and matched controls. Immunoaffinity subtraction was used to deplete the top most abundant serum proteins; the remaining serum proteins were subjected to trypsin digestion and analyzed in triplicate by LC-MS/MS. The tandem mass spectrum data were searched against the human proteome database and the resultant spectral counting data were used to estimate the relative abundance of proteins across the case/control serum pools. The spectral counting derived abundances of some candidate biomarker proteins were confirmed with multiple reaction monitoring MS assays. Results A list of 49 differentially abundant candidate proteins was compiled by applying a negative binomial regression model to the spectral counting data (p<0.01). Functional analysis with Ingenuity Pathway Analysis tools showed significant enrichment of inflammatory response proteins, key molecules in cell-cell signaling and interaction network and differential physiological responses for the two common NSCLC subtypes. Conclusions We identified a set of candidate serum biomarkers with statistically significant differential abundance across the lung cancer case/control pools which, when validated, could improve lung cancer early detection. PMID:21304412

  9. High-Throughput Identification of IMCD Proteins Using LC-MS/MS

    PubMed Central

    Pisitkun, Trairak; Bieniek, Jared; Tchapyjnikov, Dmitry; Wang, Guanghui; Wu, Wells W.; Shen, Rong-Fong; Knepper, Mark A.

    2006-01-01

    The inner medullary collecting duct (IMCD) is an important site of vasopressin-regulated water and urea transport. Here we have used protein mass spectrometry to investigate the proteome of the IMCD cell, and how it is altered in response to long-term vasopressin administration in rats. IMCDs were isolated from inner medullas of rats, and IMCD proteins were identified by liquid chromatography/tandem mass spectrometry (LC-MS/MS). We present a WWW-based “IMCD Proteome Database”, containing all IMCD proteins identified in this study (n = 704) and prior MS-based identification studies (n = 301). We used the isotope-coded affinity tag (ICAT) technique to identify IMCD proteins that change in abundance in response to vasopressin. dDAVP or vehicle was infused subcutaneously in Brattleboro rats for 3 days and IMCDs were isolated for proteomic analysis. dDAVP and control samples were labeled with different cleavable ICAT reagents (mass difference 9 amu) and mixed. This was followed by 1-D SDS-PAGE separation, in-gel trypsin digestion, biotin-avidin affinity purification, and LC-MS/MS identification and quantification. Responses to vasopressin for a total of 165 proteins were quantified. Quantification based on semiquantitative immunoblotting of 16 proteins for which antibodies were available showed a high degree of correlation with ICAT results. In addition to aquaporin-2 and γ -ENaC, five of the immunoblotted proteins were substantially altered in abundance in response to dDAVP, viz. syntaxin-7, Rap1, GAPDH, HSP70, and cathepsin D. A 28-protein vasopressin signaling network was constructed using literature-based network analysis software focusing on the newly identified proteins, providing several new hypotheses for future studies. PMID:16449382

  10. HPLC-DAD and HPLC-ESI-MS/MS methods for metabolite profiling of propolis extracts.

    PubMed

    Pellati, Federica; Orlandini, Giulia; Pinetti, Diego; Benvenuti, Stefania

    2011-07-15

    In this study, the composition of polyphenols (phenolic acids and flavonoids) in propolis extracts was investigated by HPLC-DAD and HPLC-ESI-MS/MS by comparing the performance of ion trap and triple quadrupole mass analyzers. The analyses were carried out on an Ascentis C(18) column (250mm×4.6mm I.D., 5μm), with a mobile phase composed by 0.1% formic acid in water and acetonitrile. Overall, the UV spectra, the MS and MS/MS data allowed the identification of 40 compounds. In the case of flavonoids, the triple quadrupole mass analyzer provided more collision energy if compared with the ion trap, originating product ions at best sensitivity. The HPLC method was validated in agreement with ICH guidelines: the correlation coefficients were >0.998; the limit of detection was in the range 1.6-4.6μg/ml; the recovery range was 96-105%; the intra- and inter-day %RSD values for retention times and peak areas were found to be <0.3 and 1.9%, respectively. The developed technique was applied to the analysis of hydroalcoholic extracts of propolis available on the Italian market. Although the chromatographic profile of the analyzed samples was similar, the quantitative analysis indicated that there is a great variability in the amount of the active compounds: the content of total phenolic acids ranged from 0.17 to 16.67mg/ml and the level of total flavonoids from 2.48 to 41.10mg/ml. The proposed method can be considered suitable for the phytochemical analysis of propolis extracts used in phytotherapy. PMID:21497475