Author
Latest:
Celebrating the Career of Professor Klaus K. UngerJ.J. Kirkland and J.J. DeStefano spoke to LCGC about the important contributions Dr. Klaus Unger has made to chromatography as Dr. Unger celebrates his 80th birthday.
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Innovations in Ion-Exchange Chromatography for mAb Variant AnalysisA surge in the development and commercialization of monoclonal antibody (mAb)-based ther-apeutics has driven the requirement for accurate and reproducible analytical methods for pro-tein characterization. Monoclonal antibodies are popular biologic drug candidates, but are sus-ceptible to a myriad of modifications during manufacture and complex degradation pathways during purification and storage, often leading to distinct charge variants that require character-ization and quantification. Ion‑exchange liquid chromatography (IEX) is a well-accepted and widely used technique to separate various mAb charge variant species for the sake of charac-terization and profiling. With the most recent advances in analytical technologies, IEX can be used to help ensure the selection of stable and efficacious mAb drug candidates, from discov-ery through manufacturing.
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Modern Size-Exclusion Chromatography Separations of Biosimilar Antibodies at Physiological pH and Ionic StrengthThe state of protein-derived self-associated, aggregated, and fragmented impurities in therapeutics are critical quality attributes (CQAs) and are widely monitored using non-denaturing size-exclusion chromatography (SEC).
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Advantages of Sequential or Bracketed Injection Methods to Improve the Chromatographic Analysis of BiotherapeuticsThis article explores three case studies where autosampler injection programs help to (i) reduce the carry-over observed for large nucleic acids during anion-exchange chromatography (AEX), (ii) reduce peak distortion and breakthrough for monoclonal antibodies (mAbs) during hydrophilic-interaction chromatography (HILIC), and (iii) facilitate dissolution of lipid nanoparticles (LNPs) so that a size-exclusion chromatography (SEC) method can be applied for ribonucleic acid (RNA) payload analysis.
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Nonconventional Alternatives to LC–MSAn important attribute of a novel ionization process for use in mass spectrometry (MS) is its simplicity and flexibility to be hyphenated to conventional liquid-based separation methods.
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Development of a “Freeze-Pour” Sample Preparation Method for the GC Analysis of Semivolatile Flavouring Chemicals Present in E-cigarette Refill LiquidsHS-GC analysis is presented as an excellent method for the analysis of high volatile components in e-liquids. For the analysis of semivolatile ingredients, an additional sample preparation step is proposed based on a LLE followed by a freeze-out of the matrix components.
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The Role of Liquid Chromatography and Gas Chromatography in the Analysis of Illegal Medicines and Health ProductsThis review article will give a general overview of the liquid chromatographic (LC) and gas chromatographic (GC) methods used by analytical laboratories for the detection and characterization of suspected illegal medicines and health products, including lifesaving drugs (antimicrobials and antimalarials), lifestyle drugs (erectile dysfunction drugs), and biotechnology drugs (doping peptides and skin-tanning peptides). Literature published from 2015 until early 2019 will be surveyed.
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The Role of Liquid Chromatography and Gas Chromatography in the Analysis of Illegal Medicines and Health ProductsThis review article will give a general overview of the liquid chromatographic (LC) and gas chromatographic (GC) methods used by analytical laboratories for the detection and characterization of suspected illegal medicines and health products, including lifesaving drugs (antimicrobials and antimalarials), lifestyle drugs (erectile dysfunction drugs), and biotechnology drugs (doping peptides and skin-tanning peptides). Literature published from 2015 until early 2019 will be surveyed.
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Middle-Up Characterization of the Monoclonal Antibody Infliximab by Capillary Zone Electrophoresis–Mass SpectrometryCZE–ESI‑TOF‑MS for the characterization of the mAb infliximab and its variants is presented. Infliximab was analyzed using a middle-up approach involving either reduction or digestion with the enzyme IdeS. A multilayer capillary coating of PB-DS‑PB in combination with a background electrolyte of 40% acetic acid provided efficient separation of the obtained antibody fragments, that is, LC and HC, as well as F(ab’)2 and Fc/2 parts. C-terminal lysine variants were also resolved. Recorded mass spectra of HC and Fc/2 fragments permitted assignment of 13 glycoforms and provided a quantitative profile, with G0F the most abundant glycoform (~50%). CZE–ESI-TOF-MS represents an efficient means for the straightforward analysis of a monoclonal antibody and its proteoforms.
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Middle-Up Characterization of the Monoclonal Antibody Infliximab by Capillary Zone Electrophoresis–Mass SpectrometryCZE–ESI‑TOF‑MS for the characterization of the mAb infliximab and its variants is presented. Infliximab was analyzed using a middle-up approach involving either reduction or digestion with the enzyme IdeS. A multilayer capillary coating of PB-DS‑PB in combination with a background electrolyte of 40% acetic acid provided efficient separation of the obtained antibody fragments, that is, LC and HC, as well as F(ab’)2 and Fc/2 parts. C-terminal lysine variants were also resolved. Recorded mass spectra of HC and Fc/2 fragments permitted assignment of 13 glycoforms and provided a quantitative profile, with G0F the most abundant glycoform (~50%). CZE–ESI-TOF-MS represents an efficient means for the straightforward analysis of a monoclonal antibody and its proteoforms.
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Supplementary Information: Middle-Up Characterization of the Monoclonal Antibody Infliximab by Capillary Zone Electrophoresis–Mass SpectrometryThis information is supplementary to the article “Middle-Up Characterization of the Monoclonal Antibody Infliximab by Capillary Zone Electrophoresis-Mass Spectrometry” that was published in the March 2019 issue of LCGC Europe.
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Acrylamide from CoffeeA simple, automatable cleanup method is developed for the analysis of acrylamide from coffee, yielding absolute recoveries that exceed 92% when analyzed by LC–MS-MS.
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Simultaneous Determination of Methotrexate and Sulphasalazine in Plasma by HPLC–DADHere we describe a simple and robust high performance liquid chromatography–diode array detection (HPLC–DAD) method for the simultaneous determination of methotrexate (MTX) and sulphasalazine (SSZ) from plasma. MTX and SSZ are used in combination for the treatment of rheumatoid arthritis. Using two detector wavelengths, 304 nm for MTX and 358 nm for SSZ, we were able to selectively quantitate both analytes during the same chromatographic run. The method was validated using quality control samples for critical analytical performance criteria of recovery, reproducibility, selectivity, accuracy, and precision.
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Separation and Identification of Non-Covalent Metal Complexes from Bacteria by HILIC–MSIn this study, we aimed to use a charge modulated HILIC stationary phase (iHILIC®-Fusion) to separate different siderophores of the Pseudomonas taiwanensis VLB120 bacteria.
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Separation and Identification of Non-Covalent Metal Complexes from Bacteria by HILIC–MSIn this study, we aimed to use a charge modulated HILIC stationary phase (iHILIC®-Fusion) to separate different siderophores of the Pseudomonas taiwanensis VLB120 bacteria.
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Add More Confidence to Your UHPLC–MS AnalysisFor your highly sensitive UHPLC–MS analyses, how can you reduce noise and additional signals to a minimum?
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Identifying Long-Chain and Short-Chain Branching in PolymersBranching affects macroscopic polymer properties such as crystallinity, melting temperature, toughness, ductility, and optical clarity. Two types of branching are long-chain branching (LCB) and short-chain branching (SCB), wherein the molar mass of the branches is larger or smaller than the entanglement molar mass, respectively.
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Solid-Phase Extraction of US EPA 535 for Chloroacetanilide and Acetamide Degradates in Drinking Water Samples Prior to Liquid Chromatography/Tandem Mass SpectrometryThe US EPA has implemented an exposure research program aimed at conducting drinking water research on methods as part of the Microbiological and Chemical Exposure Assessment. This research is aimed at evaluating the chemical pollutants and their role and levels in which there is an unacceptable risk to either humans or wildlife, as well as evaluating the methodologies currently being used to determine levels of chemical pollutants.
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The Preparative Use of Flow Field-Flow FractionationDemonstrating that flow field-flow fractionation can separate protein aggregates for preparative and analytical purposes.
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Rising Stars of Separation Science: Shijia TangThis month we interview Shijia Tang, principal scientist at Genentech, South San Francisco, CA, USA, about her innovative research focusing on the analysis of polymers and nanomaterials used in pharmaceutical analysis. Shijia decribes the benefits of an innovative in-line mixing modulation method for 2D-LC she developed for polymer and oligonucleotide analysis. The advantages of SEC–MALS to explore aggregation mechanisms for therapeutic constrained peptides and mRNA-lipid nanoparticles and their aggregates are also discussed.
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Pittcon 2019 PreviewPittcon celebrates its 70th year with thousands of chromatographers from around the globe and a range of industries taking over the Pennsylvania Convention Center in Philadelphia, Pennsylvania, USA, from 17–21 March 2019 for a week of education, research, instrumentation, and networking.
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Strategies to Improve Recoveries of Proteins and Peptides from Sample Containers Before LC–MS AnalysesThis article describes how to prevent the loss of sample analytes by understanding the factors responsible for poor recoveries.
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Analysis of Dioxins in Foods and Feeds Using Gas Chromatography Tandem Mass SpectrometryIn the early days of dioxin analysis, applied methods were laboratory- and time-consuming. Only GC–HRMS, which is complicated, was used. Nowadays, GC–MS/MS is suitable for control proposes. Using GC–MS/MS means that solvent consumption for sample preparation can be reduced by a factor of 10 and the purity of the obtained fraction can be enhanced, indicating that GC–MS/MS is appropriate for dioxin analysis.
Latest:
Analysis of Dioxins in Foods and Feeds Using Gas Chromatography Tandem Mass SpectrometryIn the early days of dioxin analysis, applied methods were laboratory- and time-consuming. Only GC–HRMS, which is complicated, was used. Nowadays, GC–MS/MS is suitable for control proposes. Using GC–MS/MS means that solvent consumption for sample preparation can be reduced by a factor of 10 and the purity of the obtained fraction can be enhanced, indicating that GC–MS/MS is appropriate for dioxin analysis.
Latest:
Analysis of Dioxins in Foods and Feeds Using Gas Chromatography Tandem Mass SpectrometryIn the early days of dioxin analysis, applied methods were laboratory- and time-consuming. Only GC–HRMS, which is complicated, was used. Nowadays, GC–MS/MS is suitable for control proposes. Using GC–MS/MS means that solvent consumption for sample preparation can be reduced by a factor of 10 and the purity of the obtained fraction can be enhanced, indicating that GC–MS/MS is appropriate for dioxin analysis.
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Super Charged Separations: How Utilizing New Column Chemistries Can Improve the Chromatography of Basic CompoundsWebinar Date/Time: Airing 1: Wednesday, March 20, 2024 at 11AM EDT / 3PM GMT / 4PM CET Airing 2: Wednesday, March 20, 2024 at 2PM EDT / 1PM CDT / 11AM PST
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Plant Metabolomic Workflows Using Reversed-Phase LC and HILIC with ESI-TOF-MSIn plant metabolomics, molecular fingerprints and additional molecular descriptors can be identified using recent developments in polarity-extended separations with serial coupling of reversed-phase LC and HILIC combined with ESI-TOF-MS.
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Plant Metabolomic Workflows Using Reversed-Phase LC and HILIC with ESI-TOF-MSIn plant metabolomics, molecular fingerprints and additional molecular descriptors can be identified using recent developments in polarity-extended separations with serial coupling of reversed-phase LC and HILIC combined with ESI-TOF-MS.
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Plant Metabolomic Workflows Using Reversed-Phase LC and HILIC with ESI-TOF-MSIn plant metabolomics, molecular fingerprints and additional molecular descriptors can be identified using recent developments in polarity-extended separations with serial coupling of reversed-phase LC and HILIC combined with ESI-TOF-MS.
