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Buffer Considerations for LC and LC–MSThe authors examine some critical factors with regard to buffers in LC and LC-MS research.
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An Improved SPE-LC–MS–MS Platform for the Simultaneous Quantification of Multiple Amyloid Peptides in Cerebrospinal Fluid for Preclinical or Biomarker DiscoveryFast, flexible platforms for peptide quantification are needed, particularly for a discovery setting. This type of methodology would be especially advantageous in the case of amyloid beta (a?) peptides.
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Multiple Dimensions of Separations: SPME with GCxGC and GCxGC–TOF-MSIn this article, the combination of SPME with GCxGC and GCxGC–TOF-MS is discussed using mixtures of solvents as example analytes
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Trace-Level Aliphatic Amines in Cationic DrugsThe analytical challenge treated in the present work consists in determining sub-ppb concentrations of low-molecular-weight amines in the presence of strongly retained cationic drugs by using ion chromatography (IC) with upstream in-line coupled-column matrix elimination (CCME).
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Simultaneous Headspace-GC–FID Analysis for Methanol and Ethanol in Blood, Saliva and Urine: Validation of Method and Comparison of SpecimensA simultaneous headspace-GC–FID method was validated to establish methanol and ethanol assessment in blood, urine and saliva.
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Seamless Method Transfer from UPLC Technology to Preparative LCUltraPerformance LC (UPLC) has been widely accepted by chromatographers because of improvements over HPLC in the sensitivity, resolution and speed of separations. As scientists begin to use this technology for impurity and metabolite profiling, they will need to transfer the methods to preparative LC to isolate and purify their compounds for further research. Therefore, it is necessary to systematically transfer UPLC assays not only to HPLC, but, more importantly, to preparative chromatography. In this application, we provide information on how to scale a UPLC impurity/degradant separation to a preparative LC separation.
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Fast Analysis of Charge Variants of Monoclonal Antibodies by Ion Exchange ChromatographyDevelopment and production of biopharmaceuticals is a growing segment of the pharmaceutical industry. The development of vaccines is only one - but as a result of the current H1N1 flu hysteria it is the most striking - segment of this emerging field. Recombinant proteins, ranging from insulin products to therapeutic antibodies, represent another important group of biopharmaceuticals. With the introduction of the first so-called biosimilars in Europe the demand for highly efficient analysis methods is further increasing. Newly developed stationary phases for the typical modes of biochromatography of native proteins such as SEC or IEC open up new opportunities for increasing throughput in the bioanalytical lab.
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HILIC–MS Sensitivity without SilicaWhat challenges occur when using hydrophilic interaction liquid chromatography (HILIC), and what options are available for analysis?
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Advances in the Analysis of Persistent Halogenated Organic CompoundsThis article reviews advances in the analysis of persistent halogenated organic compounds over the last century.
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Meeting Review: Latest Advances in the Analysis of Complex Environmental Matrices, 2019A biennial meeting jointly organized by the Environmental Chemistry Group, Separation Sciences Group, and the Water Science Forum, and discussing the latest advances in the analysis of complex environmental matrices, is now in its eighth year. The most recent iteration of the event occurred on Friday 22 February 2019 in the Science Suite, Royal Society of Chemistry, Burlington House, in London, UK. This meeting review offers an overview of what is happening in the industry.
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A Mass Spectrometry GlossaryHere we present an updated glossary of industry terms - a handy guide for the seasoned analyst as well as those new to the field.
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New Generation Monolithic Silica Columns for Fast, High Resolution Drug Separations without High PressuresUsing a novel new-design monolithic silica column (Chromolith? HighResolution RP-18e), fast, high resolution separations were achieved for various drug mixtures without the high pressures characteristic of modern particulate technology.
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HSS HPLC Columns: An Additional Option for Transferring Methods between HPLC and UPLC TechnologyAs UPLC users convert or replace their existing HPLC systems with UPLC systems there is a transition period where a method must be run on both platforms. Thus, having the same particle substrate and bonded phases available in HPLC and UPLC particle sizes can significantly ease the burden of method development and transfer from one platform to another. In addition to the ethylene bridged hybrid (BEH) particle, three new high strength silica (HSS) stationary phases for HPLC applications are introduced. Scalability between both column diameter and particle size is demonstrated on both UPLC and HPLC instrumentation.
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Qualitative and Quantitative Metabolite Identification for Verapamil in Rat Plasma by Sub-2-μm LC Coupled with Quadrupole TOF-MSAn effective metabolite identification study should ideally include both qualitative and quantitative information that for both identifying metabolites, and determining the rate of clearance and the metabolic routes of the parent drug. Liquid chromatography–mass spectrometry (LC–MS) is considered the standard analytical technique for metabolite identification studies. To date, however, qualitative and quantitative information has always been obtained from two separation platforms: quadrupole time-of-flight (QTof) MS for the exact mass full-scan qualitative study, and tandem quadrupole MS for the multiple reaction monitoring (MRM) quantitative study. With advancements to QTof instrumentation, specifically, recent improvements in sensitivity and dynamic range, it is now possible to perform both qualitative and quantitative experiments on a single QTof mass spectrometer. This article describes a workflow that allows simultaneous qualitative and quantitative metabolite identification studies to be..
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Quantitative Proteomic Workflow for Discovery of Early Rejection Kidney Transplant Peptide Biomarkers and Subsequent Development of SRM Assays in UrineThe accurate diagnosis of renal allograft rejection currently depends upon a biopsy. Transplant medicine would benefit greatly from the availability of noninvasive tests for early detection of rejection and immunosuppressive drug therapeutic monitoring. Only a limited number of studies have been published to date on specific proteins associated with allograft rejection. Typically, renal dysfunction due to humoral transplant rejection or other pathologies results in the increase of protein excreted in urine (1–5). In blood, endogenous peptides (not generated by trypsin digestion ex vivo) are likely candidate biomarkers for many diseases and pathologies as they are secreted from tissues and enter the bloodstream (6,7). The analysis of endogenous protein and peptide fragments in urine can provide a noninvasive, early indication of kidney transplant rejection or disease.
Latest:
Simultaneous Headspace-GC–FID Analysis for Methanol and Ethanol in Blood, Saliva and Urine: Validation of Method and Comparison of SpecimensA simultaneous headspace-GC–FID method was validated to establish methanol and ethanol assessment in blood, urine and saliva.
Latest:
Mind the Diluent: Effects of Sample Diluent on Analyte Recovery in Reversed-Phase and HILIC SeparationsThe sample solvent can have a big impact on peak shape in both reversed-phase and hydrophilic interaction liquid chromatography (HILIC) separations, especially when large volumes are injected. Diluting the sample with weak solvent can be an effective solution to mitigate this problem, but we have to be careful to not lose analytes of interest to precipitation or phase separation.
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Multiple Dimensions of Separations: SPME with GCxGC and GCxGC–TOF-MSIn this article, the combination of SPME with GCxGC and GCxGC–TOF-MS is discussed using mixtures of solvents as example analytes
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Application of Silica Monoliths for BioanalysisIn this article, the application of silica monoliths with bimodal pore structure (macro and mesopores) is described for the chromatographic analysis of biomolecules including peptides, proteins, and antibodies.
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Buffer Considerations for LC and LC–MSThe authors examine some critical factors with regard to buffers in LC and LC-MS research.
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Single Multipoint Calibration Curve for Discovery BioanalysisA single calibration curve run with staggered calibrants bracketing the unknowns is compared to running complete duplicate calibration curves, one at the beginning and one at the end of unknown sample analysis in an effort to accelerate discovery bioanalysis.
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Single Multipoint Calibration Curve for Discovery BioanalysisA single calibration curve run with staggered calibrants bracketing the unknowns is compared to running complete duplicate calibration curves, one at the beginning and one at the end of unknown sample analysis in an effort to accelerate discovery bioanalysis.
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Column Overload in Porous Layer Open Tubular (PLOT) ColumnsThe basic types of column overload (volume and mass) and the variables that most affect the sample loading capacity in PLOT column chromatography are examined.
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Chromatography Forum of the Delaware Valley Dal Nogare AwardThe 2017 Chromatography Forum of the Delaware Valley Dal Nogare Award will be presented Monday morning at Pittcon 2018 to Professor Robert Kennedy from the University of Michigan. The award will be presented by Mary Ellen McNally of EI DuPont de Nemours and Company.
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Increased Sensitivity, Improved Resolution and Faster Analysis Times For Compendial Methods: Determination of Impurities and Related Substances Using Newly Developed 2.6 µm Core-Shell Kinetex LC ColumnsRecently a newly developed Kinetex 2.6 µm core-shell chromatographic particle has been commercialized that offers the performance benefits of sub-2 µm fully-porous particles but at substantially lower operating pressures.
Latest:
Trace-Level Aliphatic Amines in Cationic DrugsThe analytical challenge treated in the present work consists in determining sub-ppb concentrations of low-molecular-weight amines in the presence of strongly retained cationic drugs by using ion chromatography (IC) with upstream in-line coupled-column matrix elimination (CCME).
Latest:
Qualitative and Quantitative Metabolite Identification for Verapamil in Rat Plasma by Sub-2-μm LC Coupled with Quadrupole TOF-MSAn effective metabolite identification study should ideally include both qualitative and quantitative information that for both identifying metabolites, and determining the rate of clearance and the metabolic routes of the parent drug. Liquid chromatography–mass spectrometry (LC–MS) is considered the standard analytical technique for metabolite identification studies. To date, however, qualitative and quantitative information has always been obtained from two separation platforms: quadrupole time-of-flight (QTof) MS for the exact mass full-scan qualitative study, and tandem quadrupole MS for the multiple reaction monitoring (MRM) quantitative study. With advancements to QTof instrumentation, specifically, recent improvements in sensitivity and dynamic range, it is now possible to perform both qualitative and quantitative experiments on a single QTof mass spectrometer. This article describes a workflow that allows simultaneous qualitative and quantitative metabolite identification studies to be..
Latest:
A Fast, Robust, and Reliable Method for Sensitively Screening Drugs of Abuse in Human Urine for Forensic ToxicologyAnalyzing drugs of abuse (DoA) in human bodily fluids is crucial for clinical research and forensic toxicology. In these routine analyses, a large number of samples must be investigated, with a potentially high laboratory cost for each sample. As such, a reliable and affordable method is required for analysis. In this article, a fast, robust, and reliable method is presented for routine, high-throughput drug screening of urine samples.
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Separation of Tryptophan Oxidized Peptides from Their Native FormsOxidation of amino acid residues can alter a protein's biological activity, half-life and immunogenicity. Peptide maps can be used to detect oxidized peptide fragments. Peptides are commonly separated by RP-HPLC; however, hydrophobic interaction chromatography (HIC) is an alternative technique offering different selectivity.
