Author
Latest:
The Role of Liquid Chromatography–Mass Spectrometry in the Characterization of Therapeutic Monoclonal AntibodiesA review of the central role LC–MS plays in characterizing mAbs and biosimilars, including highlights of top-down and middle-up approaches to measure the intact masses of mAbs and their subunits, the current state of peptide mapping techniques, and glycoprofiling methods.
Latest:
The Role of Liquid Chromatography–Mass Spectrometry in the Characterization of Therapeutic Monoclonal AntibodiesA review of the central role LC–MS plays in characterizing mAbs and biosimilars, including highlights of top-down and middle-up approaches to measure the intact masses of mAbs and their subunits, the current state of peptide mapping techniques, and glycoprofiling methods.
Latest:
The Role of Liquid Chromatography–Mass Spectrometry in the Characterization of Therapeutic Monoclonal AntibodiesA review of the central role LC–MS plays in characterizing mAbs and biosimilars, including highlights of top-down and middle-up approaches to measure the intact masses of mAbs and their subunits, the current state of peptide mapping techniques, and glycoprofiling methods.
Latest:
The Role of Liquid Chromatography–Mass Spectrometry in the Characterization of Therapeutic Monoclonal AntibodiesA review of the central role LC–MS plays in characterizing mAbs and biosimilars, including highlights of top-down and middle-up approaches to measure the intact masses of mAbs and their subunits, the current state of peptide mapping techniques, and glycoprofiling methods.
Latest:
Analysis of Pesticides in Citrus Oil Using PTV Backflush with GC–MS-MS Triple Quadrupole for High Sample ThroughputInternational regulations on maximum residue levels (MRLs) of pesticides in food cover hundreds of individual contaminants at the 10 ppb or below range. The analysis of citrus oil for pesticide contamination holds specific challenges.
Latest:
Profiling Nonionic Surfactants Applied in Pharmaceutical Formulations Using Comprehensive Two-Dimensional LC with ELSD and MS DetectionComprehensive two-dimensional liquid chromatography (2D-LC) was used for detailed profiling of various nonionic ethoxylated surfactants applied in pharmaceutical formulations. Hydrophilic-interaction chromatography (HILIC) and reversed-phase liquid chromatography (LC) were used as the first and second dimensions, respectively. Detection was performed with evaporative light-scattering detection (ELSD) for general profiling and with single-quadrupole mass spectrometry (MS) for structure elucidation of individual peaks and for class-type confirmation of peak-groups.
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Evaluation of QuECheRS, Cartridge SPE Cleanup, and Gas Chromatography Time-of-Flight Mass Spectrometry for the Analysis of Pesticides in Dietary SupplementsThe authors evaluate a method for detecting pesticide residues in dandelion root powder.
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Matrix-Assisted Laser Desorption-Ionization Imaging Mass Spectrometry for Direct Tissue AnalysisA summary of the most recent advances in sample preparation, instrumentation, and data-processing techniques for MALDI-IMS
Latest:
Matrix-Assisted Laser Desorption-Ionization Imaging Mass Spectrometry for Direct Tissue AnalysisA summary of the most recent advances in sample preparation, instrumentation, and data-processing techniques for MALDI-IMS
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Comparing Multivariate Eluent Design Spaces for Systematic Characterization of (U)HPLC ColumnsPresenting a novel chromatographic modelling method to establish QbD-compliant comparative testing of eluent design spaces.
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UHPLC or HPLC? The Choice is YoursSergio Guazzotti speaks to Janet Kelsey about the advantages of UHPLC over HPLC and issues to consider when selecting this technique.
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Effects of Column Inner Diameter and Packed Bed Heterogeneities on Chromatographic PerformanceIn recent years industry has been moving to columns with smaller and smaller inner diameters - moving from 4.6 mm and 3.0 mm i.d. columns to 2.1 mm, 1.0 mm, and even smaller. While small inner diameter columns have some clear advantages, they also bring challenges. Reduction of extracolumn volumes must be given greater consideration by both customers and manufacturers. This article focuses on the sources of band broadening within high performance liquid chromatography (HPLC) columns with an emphasis on eddy dispersion. The physical mechanisms of dispersion are discussed and a review of the current literature as it pertains to small inner diameter columns is presented.
Latest:
Matrix-Assisted Laser Desorption-Ionization Imaging Mass Spectrometry for Direct Tissue AnalysisA summary of the most recent advances in sample preparation, instrumentation, and data-processing techniques for MALDI-IMS
Latest:
The Current and Future State of Top-Down Protein Sequencing by ESI-Tandem Mass SpectrometryIn this column, we introduce the basics of today’s approaches for doing intact protein dissociation with mass spectrometry (MS), or top-down sequencing (that is, rather than the more conventional peptide-based “bottom-up” sequencing where future improvements might occur, advantages and limitations of using top-down sequencing, possible applications, and why it has become such an important and pursued research area for many.
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HPLC–MS Characterization of 99.5% Pure Compounds Using Miniaturized Mass DetectorDetecting impurities in any chemical reaction is becoming increasingly important to detect those present at low levels (for example, 0.5%).
Latest:
HPLC–MS Characterization of 99.5% Pure Compounds Using Miniaturized Mass DetectorDetecting impurities in any chemical reaction is becoming increasingly important to detect those present at low levels (for example, 0.5%).
Latest:
UHPLC Instrument Variations and Approaches to Ease the Method Transfer ProcessUltrahigh-pressure liquid chromatography (UHPLC) instruments from different manufacturers and instruments with different configurations can produce significant variations in chromatographic separation. The variety in instrument configuration increases the complexity of the method development process, which now requires a more thorough evaluation of the effect of instrument variations on the method. The studies presented here determined the typical interinstrument variations in dwell volume, extracolumn dispersion, and mixing efficiency as measured by mobile-phase compositional accuracy. Additionally, the dwell volume and extracolumn dispersion were independently and systematically varied to evaluate the resulting impact on resolution for a small-molecule test mixture during gradient elution. To account for these interinstrument variations, dwell volume and wash-out volume method translation and adjustment techniques were evaluated.
Latest:
UHPLC Instrument Variations and Approaches to Ease the Method Transfer ProcessUltrahigh-pressure liquid chromatography (UHPLC) instruments from different manufacturers and instruments with different configurations can produce significant variations in chromatographic separation. The variety in instrument configuration increases the complexity of the method development process, which now requires a more thorough evaluation of the effect of instrument variations on the method. The studies presented here determined the typical interinstrument variations in dwell volume, extracolumn dispersion, and mixing efficiency as measured by mobile-phase compositional accuracy. Additionally, the dwell volume and extracolumn dispersion were independently and systematically varied to evaluate the resulting impact on resolution for a small-molecule test mixture during gradient elution. To account for these interinstrument variations, dwell volume and wash-out volume method translation and adjustment techniques were evaluated.
Latest:
One-Dimensional Simultaneous Achiral and Chiral AnalysisHaving a mixed-mode column that can provide both achiral and chiral resolution in one-dimension (1D) would significantly improve impurity profile understanding and reduce testing workload.
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Improved Analysis of Preservatives in Cosmetics Using a Unique Core-Shell PhasePhenomenex Application Note
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Routine Multiresidue Pesticide Analysis using the Agilent 6470 Triple Quadrupole Mass SpectrometerThis application note describes a UHPLC/MS/MS-based method for the screening and quantification of more than 250 pesticides and pesticide metabolites in food samples.
Latest:
Routine Multiresidue Pesticide Analysis using the Agilent 6470 Triple Quadrupole Mass SpectrometerThis application note describes a UHPLC/MS/MS-based method for the screening and quantification of more than 250 pesticides and pesticide metabolites in food samples.
Latest:
Fast and Sensitive Analysis of Amino Acids Using Automated Pre-Column DerivatizationThe building blocks of peptides and proteins, amino acids, are present in animals, humans, and plants. The analysis of amino acids is of essential significance in several areas including food science, clinical diagnostics, and pharmaceutical products research. Classical liquid chromatography (LC) determination of amino acids is performed with sample pretreatment including pre-column as well as post-column derivatization to improve or enable spectroscopic detection.
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What’s in Your Morning Drink? Comprehensive Characterization of Tea and Coffee Extracts by GC×GC–TOF-MSThis poster describes how GC×GC–TOF MS is used to quickly and confidently identify key flavour compounds in tea and coffee that would be subject to extensive co-elution in a conventional GC–MS system.
Latest:
What’s in Your Morning Drink? Comprehensive Characterization of Tea and Coffee Extracts by GC×GC–TOF-MSThis poster describes how GC×GC–TOF MS is used to quickly and confidently identify key flavour compounds in tea and coffee that would be subject to extensive co-elution in a conventional GC–MS system.
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Coupling Gas Chromatography with Ion Mobility SpectrometryChromatography connected with ion mobility spectrometry (IMS) is not commonly used, but is being investigated more. IMS is an independent analytical technique with very good detectability and a rather small separation ability. One favourable property of IMS is that it can work with ambient pressure and can be easily connected to a gas chromatograph. Analytical applications of GC–MS are very different and encompass investigations into food, medical science, environment, drugs of abuse, chemical warfare agents, and explosives.
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Ion Mobility Spectrometers as Chromatographic DetectorsInterest in connecting ion mobility spectrometry (IMS) to GC and especially to LC is now growing. One favorable property of IMS is that it can work with ambient pressure and can be easily connected to a gas or liquid chromatograph. Analytical applications of GC–MS and LC–MS are very different and encompass investigations into food, medical science, environment, drugs of abuse, chemical warfare agents, and explosives.
