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Analysis of Fusarium Toxins Using LC–MS-MS: Application to Various Food and Feed MatricesCo-occurrence of several mycotoxins (deoxynivalenol, zearalenone, T-2-toxin, HT-2 toxin) produced by field fungi, such as Fusarium graminearum and Fusarium culmorum, requires several analysis methods for their characterization. A reliable method for the determination of type A- and B-trichothecenes and zearalenone in cereal-based samples is presented. To achieve optimal mass spectrometric detection, electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) were compared. Best results were obtained with ESI by implementing a two-period switching for the ionization polarity. The limit of quantification differs for each individual substance within the range 1–10 ppb. Mean recoveries using a standardized clean-up procedure were in the 54–93% range.
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Large-Scale Targeted Protein Quantification Using Wide Selected-Ion Monitoring Data-Independent AcquisitionThis article describes the development of a new data-independent acquisition (DIA) workflow for protein quantification that uses a mass spectrometer that combines three types of mass analyzers to achieve lower limits of detection (LOD), higher sensitivity, more accurate quantitative results, wider dynamic range, and better reproducibility than existing high-resolution accurate-mass (HRAM) tandem mass spectrometry (MS-MS) DIA workflows.
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Improved LC–MS Performance — A Three-Step Method for Minimizing Background Signals and Increasing Ionization EfficiencyOne problem frequently encountered in LC–MS is the appearance of mass peaks, which appear totally unrelated to the samples run - "ghost" mass peaks. It is impossible to differentiate whether these signals come from an unknown component in the sample co-eluting with a known peak, or from an impurity in the mobile phase or from some residual contamination "bleeding" from the column.
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A New Tool for Mass Analysis of Unknown Molecules: High-Resolution Multistep Tandem MS with Wide Dynamic Range Quantitative AnalysisMass spectrometers are effective for identifying and quantifying unknown molecules, such as disease-related proteins and small molecules in pharmaceutical research and medical diagnosis. In addition, mass spectrometry (MS) can be particularly powerful when analyzing molecules with complex structures, such as posttranslationally modified proteins. Among various MS approaches, high-resolution multistep tandem MS (MS-MS) is an emerging methodology for accurate identification of complex molecules. In this article, we describe a new approach for mass analysis with enhanced quantitative capability combined with high-resolution multistep MS-MS, where the dynamic range of quantitation covers four orders of magnitude.
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Gas Chromatographic Techniques for the Analysis of Chemical Warfare AgentsThe complexity of the systems that are used vary from standard GC configurations to assess the effectiveness of protective clothing to trace analysis of biomedical samples with complex GC configuration.
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Metabolomics Workflows: Combining Untargeted Discovery-Based and Targeted Confirmation Approaches for Mining Metabolomics DataThe metabolomics workflow described here combines untargeted (discovery) quadrupole time-of-flight (Q-TOF) liquid chromatography–mass spectrometry (LC–MS), targeted (confirmation) triple-quadrupole LC–MS-MS, and sophisticated data mining as an effective means to elucidate metabolite changes.
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Improving Injection Consistency Using N-Methyl-2-Pyrrolidone as a GC Syringe WashOptimizing peak shape in capillary gas chromatography (GC) is essential for the consistent, accurate analysis of residual solvents in pharmaceutical compounds.
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Improving the Confidence of Unknown Compound Identification by First Responder Mobile GC–MS Laboratories...A novel method that significantly improves the accuracy and reliability of "unknown" compound identification for volatile organic compounds by GC-MS is described.
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Facilitated Column Selection in Reversed-Phase Liquid Chromatography for Pharmaceutical SeparationsThis article gives an overview of the performance of a previously developed system for the ranking of C18 reversed-phase columns applied to different pharmaceutical analyses. The separation of eight different drug substances from their respective impurities was studied. The chromatographic procedure for acetylsalicylic acid, clindamycin hydrochloride, buflomedil hydrochloride, chloramphenicol sodium succinate, phenoxymethylpenicillin and nimesulide was performed according to the corresponding European Pharmacopoeia monograph. The separations of dihydrostreptomycin sulphate and vancomycin were performed according to literature. It was found that that the column ranking system is a helpful tool in the selection of suitable columns in these analyses.
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Analysis of Biodiesels Using LC–MSPreliminary studies of biodiesel samples by a high speed LC–MS system using electrospray ionization and a patented cone-wash feature demonstrate that LC–MS reduces the analysis time to 20 minutes and reveals information about higher molecular weight compounds in biodiesel while still detecting many low molecular weight chemicals, including FAMEs, at high sensitivity.
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Facilitated Column Selection in Reversed-Phase Liquid Chromatography for Pharmaceutical SeparationsThis article gives an overview of the performance of a previously developed system for the ranking of C18 reversed-phase columns applied to different pharmaceutical analyses. The separation of eight different drug substances from their respective impurities was studied. The chromatographic procedure for acetylsalicylic acid, clindamycin hydrochloride, buflomedil hydrochloride, chloramphenicol sodium succinate, phenoxymethylpenicillin and nimesulide was performed according to the corresponding European Pharmacopoeia monograph. The separations of dihydrostreptomycin sulphate and vancomycin were performed according to literature. It was found that that the column ranking system is a helpful tool in the selection of suitable columns in these analyses.
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Electron-Capture Dissociation in a Radio-Frequency Linear Ion TrapHere we describe a new compact device for electron-capture dissociation (ECD) analysis of large peptides and posttranslational modifications of proteins, which can be difficult to analyze via conventional dissociation techniques such as collision-induced dissociation (CID). The new compact device realizes ECD in a radio frequency (RF) linear ion trap equipped with a small permanent magnet, which is significantly different than the large and maintenance-intensive superconducting magnet required for conventional ECD in Fourier-transform ion cyclotron resonance mass spectrometers. In addition to its compactness and ease of operation, an additional merit of an RF linear ion trap ECD is that its reaction speed is fast, comparable to CID, enabling data acquisition on the liquid-chromatography (LC) time scale. We interfaced the linear-trap ECD device to a time-of-flight mass spectrometer to obtain ECD spectra of phosphorylated peptides injected into a liquid chromatograph, infused glycopeptides, and intact small..
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On-line SEC–Py-GC–MS for the Automated Comprehensive Characterization of CopolymersThe pyrolysis fragments are first refocused on the top of the GC column, then separated and finally detected by the MS. At the end of the GC run the SEC flow is resumed again and the entire process is repeated.
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Whither Gas Chromatography? New Tools ~ New SolutionsWe might well ask “Where is gas chromatography (GC) heading?” For many analysts, the answer may be just “more of the same,” reflecting that GC is mature and that most analysis tasks and sample types have been tried and tested. In this scenario, any changes to the basic method may be marginal—sample introduction, and maybe a new detector? But beneath this status quo is an undercurrent of passion, excitement, and power.
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High-Throughput Quantitative LC-MS-MS Assays by On-Line Extraction Using Monolithic SupportLC-MS-MS has become a widely used technique for the fast and sensitive quantitation of small molecules. In this article, this approach has been extended to high-throughput quantitative LC-MS-MS analysis under GLP applications for a drug candidate in development from preclinical animal studies through clinical development.
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ICP-MS: When Sensitivity Does MatterIt makes intuitive sense - the higher the sensitivity of an inductively coupled plasma–mass spectrometry (ICP-MS) system, the lower the detection limit. But there are many factors that affect the detection limit for a given isotope in a given sample. These factors include sensitivity, background noise, and interferences.
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Electron-Capture Dissociation in a Radio-Frequency Linear Ion TrapHere we describe a new compact device for electron-capture dissociation (ECD) analysis of large peptides and posttranslational modifications of proteins, which can be difficult to analyze via conventional dissociation techniques such as collision-induced dissociation (CID). The new compact device realizes ECD in a radio frequency (RF) linear ion trap equipped with a small permanent magnet, which is significantly different than the large and maintenance-intensive superconducting magnet required for conventional ECD in Fourier-transform ion cyclotron resonance mass spectrometers. In addition to its compactness and ease of operation, an additional merit of an RF linear ion trap ECD is that its reaction speed is fast, comparable to CID, enabling data acquisition on the liquid-chromatography (LC) time scale. We interfaced the linear-trap ECD device to a time-of-flight mass spectrometer to obtain ECD spectra of phosphorylated peptides injected into a liquid chromatograph, infused glycopeptides, and intact small..
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Analysis of Secondary Metabolites from Myxobacteria using ESI-TOF–MS and PCAThe exploration of myxobacterial metabolite profiles by LC–MS screening for the presence of new natural products is described. Extracts from fermentations of Myxococcus strains are analysed by UPLC-coupled ESI-TOF mass spectrometry and the obtained data are processed using principal component analysis (PCA). The generation of molecular formulae from accurate mass measurements facilitates rapid compound identification.
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PAT Initiatives for QC/QA Operations: Enabling Paperless Processes for Manufacturing Batch Records and QC LaboratoriesThis paper outlines the current situation in manufacturing and quality operations relative to industry compliance initiatives and manufacturing challenges. It profiles an innovative ?method-centric? software platform, designed for the analyst or operator, to electronically execute and man-age quality control testing protocols and production batch records, yielding significant reductions in overall product release cycle time.
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Identifying Packaging-Related Drug Product ImpuritiesThis month's instalment of "MS in Practice" provides a slightly different view of how practitioners employ the skills of interpretation that have been the focus in recent columns.
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Determination of Phthalate Esters in Child Care Products and Children's Toys by Gas Chromatography–Mass Spectrometry (GC–MS)The Consumer Product Safety Improvement Act of 2008 (CPSIA) requires testing of child care products and toys for selected phthalate esters by GC–MS.
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BioPharma Compass: A Fully Automated Solution for Characterization and QC of Intact and Digested ProteinsBioPharma Compass? is a fully automated solution for the rapid characterization of biopharmaceutical products such as proteins, peptides, RNA, and DNA. This push button solution assists nonspecialist operators to generate high quality, accurate data for automatic comparison with laboratory reference standards. Automated, visual reports are then generated for each sample and important information regarding a products purity and identity can be observed at a glance. In this application note, we will apply the BioPharma Compass workflow to the QC characterization of two proteins including intact IgG1 and digested transferrin.
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Membrane-Assisted Liquid–Liquid Extraction Trace Analysis of Pharmaceutical Compounds in Aquatic EnvironmentsThe concept of membrane-controlled processes is widespread in nature. Nearly all biological mechanisms concerning mass transport and exchange are regulated by membrane barriers and a variety of technical and biotechnological applications have been devised based on this mechanism. Membrane applications in analytical chemistry are geared towards the enrichment of target substances from an aqueous solution or the separation of compounds from a complex matrix. This article describes membrane-assisted extraction processes to separate traces of polar pharmaceutical substances the so called emerging micropollutants from aqueous samples. Basic prospects and examples of membrane-supported extractions are presented.
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Key LC–MS Techniques Benefit Life Sciences ResearchersState-of-the-art mass spectrometry (MS) techniques of growing importance to life sciences research now include not just liquid chromatography (LC)–MSn (n = 2–11), but also LC–matrix-assisted laser desorption ionization-time-of-flight (MALDI-TOF), LC-MALDI-TOF-TOF, electrospray ionization (ESI)-TOF, and LC-Fourier transform (FT) MS.
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FAIMS Removes Chemical Background and Interference from the Analysis of Linoleic Acid in Cancer Cell ExtractsAssay sensitivity is the lowest concentration at which a targeted analyte can be measured and is often limited by chemical background or co-eluting interferences. FAIMS in combination with liquid chromatography (LC) and zero neutral loss tandem MS was used to remove chemical background and co-eluting interferences from the analysis of linoleic acid in cancer cell extracts. Concentration of endogenous linoleic acid was determined from back-calculation of standard calibration samples fortified with deuterium-labeled linoleic acid. No internal standard was used. LC–MS-MS analysis of the cancer cell extracts resulted in an increase in signal-to-noise ratio of 10-fold. The assay sensitivity was increased 10 times over the traditional LC–MS-MS experiment exclusively due to the new FAIMS technology.
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Screening Acid-Base Constants by Capillary ElectrophoresisThe acid-base constants of the most frequently used antianginals (diltiazem, nadolol, propranolol and verapamil) were determined using capillary zone electrophoresis (CZE). This method is based on measuring the electrophoretic mobility of the solute as a function of pH. The buffer employed was composed of borate-phosphate buffered across the pH range of 3.0–11.2. The acid-base constants were determined by performing linear and non-linear regression on the data obtained. The results were compared with those reported in literature and with those obtained by a spectrophotometric method. After comparison of the values, no significant differences were observed between the three acid-base constants.
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Advances in Liquid Chromatography–Tandem Mass Spectrometry (LC–MS/MS)-Based Quantitation of Biopharmaceuticals in Biological SamplesThe technical requirements for a successful LC–MS/MS method for the quantitation of biopharmaceuticals are presented and the advantages and disadvantages compared to ligand-binding assays are evaluated.
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New Sample Fractionation Strategies for Proteomic Analyses by LC–MSMass spectrometry has long been a preferred tool for protein identification and biomarker discovery, but preparation of biological samples remains a challenge. Hindrances include the wide range of protein concentrations, sample complexity, and loss or alteration of important proteins due to sample handling. This article describes recent developments in sample fractionation technologies that are overcoming these challenges in interesting ways and are enabling in-depth proteomic studies that were not possible in the past.
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The Effect of Modifier on Selectivity in Reversed-Phase High Performance Liquid ChromatographyThe retention behaviour of several compounds has been compared for their selectivity using reversed-phase high performance liquid chromatography with binary water mobile phases composed of methanol, acetonitrile or tetrahydrofuran as modifiers.
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FAIMS Removes Chemical Background and Interference from the Analysis of Linoleic Acid in Cancer Cell ExtractsAssay sensitivity is the lowest concentration at which a targeted analyte can be measured and is often limited by chemical background or co-eluting interferences. FAIMS in combination with liquid chromatography (LC) and zero neutral loss tandem MS was used to remove chemical background and co-eluting interferences from the analysis of linoleic acid in cancer cell extracts. Concentration of endogenous linoleic acid was determined from back-calculation of standard calibration samples fortified with deuterium-labeled linoleic acid. No internal standard was used. LC–MS-MS analysis of the cancer cell extracts resulted in an increase in signal-to-noise ratio of 10-fold. The assay sensitivity was increased 10 times over the traditional LC–MS-MS experiment exclusively due to the new FAIMS technology.
