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Alternative Modes of Liquid Chromatography for OligonucleotidesThis episode focuses on alternative modes of liquid chromatography (LC) for oligonucleotides as current go-to chromatographic modes may face significant changes in the future.
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Imaging Mass Spectrometry: Current Performance and Upcoming ChallengesA critical look into the future of imaging mass spectrometry is made by addressing some of the fundamental and technical challenges that still need to be overcome.
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High-Resolution Native Mass Spectrometry Opens the Door for Detailed Analyses of Intact Protein ComplexesNative mass spectrometry, the method by which noncovalent protein complexes are retained in the gas phase for intact mass analysis, is gaining interest as a method for intact protein characterization. The development of a modified orbital ion trap platform for high-resolution analyses has expanded the role of native mass spectrometry to address the challenges of intact protein characterization.
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Reducing Microplastic Content in Ultrapure WaterMicroplastics in water are a major concern, found even in tap water and human bodies. Learn how Sartorius Arium® Pro VF series removes them effectively.
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Validation of LC–MS-MS Methods for the Determination of Ibuprofen in Miniature Swine Plasma and Synovial FluidPublished methods for the determination of ibuprofen in biological fluids by liquid chromatography (LC)–UV or LC–mass spectrometry (MS)-MS have quantitation ranges consistent with the relatively high but typical ibuprofen dose (200–800 mg), generally having lower limits of quantitation in the low micrograms-per-milliliter range. For the analysis of plasma and synovial fluid samples from preclinical (miniature swine) studies utilizing a novel ibuprofen dosage form, LC–MS-MS methods were developed and validated over the 10–1000 ng/mL range. Ibuprofen undergoes biotransformation to ibuprofen acyl glucuronide and sublimes under routine bioanalytical sample handling conditions. Procedures were implemented to minimize the impact of these potential liabilities.
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Back to the Basics: Considering Carryover, Column Back Pressure, and Wavelength When Developing Chromatographic MethodsThe parameters that should be considered in the optimization of HPLC methods are explained and then illustrated through the analysis of two commercial agricultural products.
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Comprehensive Two-dimensional Liquid Chromatography (LC×LC): A ReviewIn this review, practical principles and guidelines for designing LCxLC methods are given.
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Size-Exclusion Chromatography for the Analysis of Complex and Novel Biotherapeutic ProductsThis study presents applications of size-exclusion chromatography (SEC) for characterization and quality control of novel biotherapeutic products, including antibody–drug conjugates, hydrophobic proteins, and coformulations. Examples of modifying SEC mobile-phase composition and running conditions to modulate the separation are discussed, as well as approaches and strategies for analyzing atypical protein products such as coformulations.
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Chemical Fingerprinting of Mobile Volatile Organic Compounds in Soil by Dynamic Headspace–Thermal Desorption−Gas Chromatography− Mass SpectrometryThis article describes and tests a dynamic DHS−TD−GC−MS method for the fingerprinting analysis of mobile volatile organic compounds in soil.
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Fundamental and Practical Aspects of Liquid Chromatography and Capillary Electromigration Techniques for the Analysis of Phenolic Compounds in Plants and Plant-Derived Food, Part 2: Capillary Electromigration TechniquesAnalytical separation techniques based on the differential migration velocities of analytes under the action of an electric field are gaining increasing acceptance for the analysis of phenolic compounds in edible and medicinal plants and in plant-derived food products. In Part 2 of this review article the authors discuss the fundamental principles and practical aspects of electromigration techniques, including capillary zone electrophoresis (CZE), micellar electrokinetic chromatography (MEKC), and capillary electrochromatography (CEC). The development of two-dimensional systems, performed by coupling either liquid chromatography (LC) with an electromigration technique or two electromigration techniques, operated under different separation mechanisms, is also discussed.
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Fundamental and Practical Aspects of Liquid Chromatography and Capillary Electromigration Techniques for the Analysis of Phenolic Compounds in Plants and Plant-Derived Food, Part 2: Capillary Electromigration TechniquesAnalytical separation techniques based on the differential migration velocities of analytes under the action of an electric field are gaining increasing acceptance for the analysis of phenolic compounds in edible and medicinal plants and in plant-derived food products. In Part 2 of this review article the authors discuss the fundamental principles and practical aspects of electromigration techniques, including capillary zone electrophoresis (CZE), micellar electrokinetic chromatography (MEKC), and capillary electrochromatography (CEC). The development of two-dimensional systems, performed by coupling either liquid chromatography (LC) with an electromigration technique or two electromigration techniques, operated under different separation mechanisms, is also discussed.
Latest:
Fundamental and Practical Aspects of Liquid Chromatography and Capillary Electromigration Techniques for the Analysis of Phenolic Compounds in Plants and Plant-Derived Food, Part 2: Capillary Electromigration TechniquesAnalytical separation techniques based on the differential migration velocities of analytes under the action of an electric field are gaining increasing acceptance for the analysis of phenolic compounds in edible and medicinal plants and in plant-derived food products. In Part 2 of this review article the authors discuss the fundamental principles and practical aspects of electromigration techniques, including capillary zone electrophoresis (CZE), micellar electrokinetic chromatography (MEKC), and capillary electrochromatography (CEC). The development of two-dimensional systems, performed by coupling either liquid chromatography (LC) with an electromigration technique or two electromigration techniques, operated under different separation mechanisms, is also discussed.
Latest:
Fundamental and Practical Aspects of Liquid Chromatography and Capillary Electromigration Techniques for the Analysis of Phenolic Compounds in Plants and Plant-Derived Food, Part 2: Capillary Electromigration TechniquesAnalytical separation techniques based on the differential migration velocities of analytes under the action of an electric field are gaining increasing acceptance for the analysis of phenolic compounds in edible and medicinal plants and in plant-derived food products. In Part 2 of this review article the authors discuss the fundamental principles and practical aspects of electromigration techniques, including capillary zone electrophoresis (CZE), micellar electrokinetic chromatography (MEKC), and capillary electrochromatography (CEC). The development of two-dimensional systems, performed by coupling either liquid chromatography (LC) with an electromigration technique or two electromigration techniques, operated under different separation mechanisms, is also discussed.
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Molecular Structure of Poly(Lactic-co-Glycolic acid) by SEC with Advanced DetectionThe macroscopic properties of material based on poly(D,L-lactic-co-glycolic acid) (PLGA) polymers are tunable by molar mass distribution and degree of branching, enabling optimization for applications in the pharmaceutical and medical industries. Size-exclusion chromatography followed by online multi-angle light scattering with intrinsic viscosity detection (SEC–MALS–IV) is an advanced analytical method for determining absolute molar mass distributions, identifying polymer conformation and quantifying branching. SEC–MALS–IV overcomes the errors that can be encountered in molar mass determined by conventional SEC, which arise from chemical composition and molecular structure, and provides comprehensive characterization of PLGA to facilitate the targeted development of optimized polymer.
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Optimization of Sample Preparation for Pesticide Analysis in Oil-Based Cannabis Products Using LipiFiltr®This application note outlines the performance benefits achieved with UCT’s LipiFiltr® cleanup cartridge for the analysis of pesticides in oil-based cannabis products using LC–MS/MS analysis.
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Analysis of Phospholipid Classes by iHILIC®-FusionPhospholipids (PLs) are the major components of cellular membranes. They are important for the functionality of membrane proteins or serve as precursors for second messengers. Several studies reveal the role of PL alterations in various diseases such as cancer (1). Therefore, it is crucial to identify and quantify PLs in complex biological samples for lipidomic studies and clinical research.
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Analysis of Polyethylene by Pyrolysis-GC×GC–MSThis application note shows the pyrolysis-GC×GC–HRMS profiles of crude oils for more detailed separations and more complete characterization of complex matrices, especially on the speciation of heteroatoms such as sulphur-containing compounds.
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Combining Sorptive Extraction with Two-Dimensional Gas Chromatography for the Flavour Profiling of MilkThis proof-of-principle study shows that polymer-based sorptive extraction probes, coupled with secondary focusing by thermal desorption and analysis by flow-modulated GC×GC–TOF-MS/FID, can be used to separate and identify flavour compounds in milk. As well as comparing the profiles of dairy and non-dairy milks, this article highlights the practical benefits of this sampling procedure, the ability of two-dimensional GC to physically separate components that would coelute in one-dimensional GC, and the use of software tools to improve workflow.
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Automated Multicolumn Purification of a Histidine-Tagged ProteinApproximately 40% of recombinant proteins that are purified use a histidine tag for easy capture. This article covers how to automate the purification of histidine-tagged proteins and how purification conditions can be optimized to an automated four-step purification scheme that uses affinity-, ion exchange-, and size-exclusion columns. Using a multistep purification scheme removes the manual steps that cause loss of precious proteins and take more time, like dialysis, collection, and reinjecting samples. The final purification scheme reduces a 3–4-day process to 11.5 h from start to finish, all while improving reproducibility, yield, and comparable purity.
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Automated Multicolumn Purification of a Histidine-Tagged ProteinApproximately 40% of recombinant proteins that are purified use a histidine tag for easy capture. This article covers how to automate the purification of histidine-tagged proteins and how purification conditions can be optimized to an automated four-step purification scheme that uses affinity-, ion exchange-, and size-exclusion columns. Using a multistep purification scheme removes the manual steps that cause loss of precious proteins and take more time, like dialysis, collection, and reinjecting samples. The final purification scheme reduces a 3–4-day process to 11.5 h from start to finish, all while improving reproducibility, yield, and comparable purity.
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Application of a GPC-LC–MS/MS Method for the Determination of 31 Mycotoxins in Edible OIlsGel Permeation Chromatography (GPC) is widely used for sample clean up in mycotoxin analysis. The most commonly described methods use GPC columns packed with SX-3 BioBeads suitable for cleaning Zearalenone, Aflatoxins, and Trichothesenes from edible oils and fatty matrices. Separation of Fumonisins from the oil fraction are inadequate with this column.
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Fast Analysis of Third-Generation Cephalosporins in Human Plasma by SPE and HPLC MethodsA fast, selective, and reproducible high performance liquid chromatography (HPLC) method was developed and validated for the analyses of third-generation cephalosporin antibiotics, namely, ceftriaxone, cefixime, and cefdinir in human plasma. The analysis was carried out on a 150 mm Ã- 4.6 mm, 5.0-µm C18 column. The mobile phase used was 80:20 (v/v) 50 mmM phosphate buffer (pH 5.0)–methanol at a flow rate of 1.0 mL/min with 230-nm UV detection.
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Detection of Pyrethroids in Surface Water and SedimentA sensitive method for quantitation of pyrethroids in surface water and sediment samples using GC?MS?MS is proposed.
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Molecular Weight Analysis of Glatiramer Acetate and Related Compounds by Size-Exclusion Chromatography with Multi-Angle Light Scattering Detection (SEC-MALS)A method was developed for the molecular weight characterization of heterogeneous polymer mixtures, such as heparins and glatiramer acetate, noting that single molecular structures are not adequate for creating a molecular weight calibration curve. That limitation is overcome in this work, which demonstrates method validation and application to process samples.
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Detection and Identification of Natural Antioxidants in Edible Oils Using LC Fractionation with Off-Line Effect-Based DetectionMultiple fractions can be tested in parallel with this fast method.
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Monoclonal Antibody Analysis (May 2023)This application note shows that a single column to be used for the analysis of a wide range of molecular sizes, from intact proteins and monoclonal antibodies to digested peptides.
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Epitope Mapping of an Interleukin Receptor for Three Therapeutic Antibodies by Hydrogen-Deuterium Exchange Mass SpectrometryAmong all the analytical techniques available for epitope mapping studies, hydrogen–deuterium exchange mass spectrometry (HDX-MS) is usually the fastest and easiest to carry out. We present here the epitope mapping of three distinct monoclonal antibody (mAb) candidates targeting the same antigen, an interleukin receptor. The goal is to establish the binding mode of these mAbs, and explain possible differences observed for in vitro binding and in vivo function.
