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Untargeted LC–MS Lipidomics with Data Independent Acquisition using Sequential Window Acquisition of All Theoretical Fragment-Ion SpectraA focus on untargeted UHPLC–MS/MS lipidomics with data independent acquisition using SWATH technology. This article explores the wide-ranging potential and peculiarities of SWATH–MS hyphenated with UHPLC for the profiling of lipidomes of various biological samples.
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Overcoming Incomplete Peptide Mapping of Antibody Complementarity-Determining Regions with Alternate Digestion WorkflowsPepsin digestion and guanidine hydrochloride post-digestion can improve sequence coverage in antibody peptide mapping compared with trypsin digestion.
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Multidimensional Gas Chromatography: Benefits and Considerations for Current and Prospective UsersWhen should multidimensional GC approaches be used for analyzing complex samples and analytes?
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Applying Sustainability Concepts to Modern Liquid ChromatographyGovernments are striving to implement policy changes towards a greater use of green technology, specifically around the generation of energy. Individuals and industrial organizations have also taken up the challenge, and now many companies are driving to significantly reduce their environmental footprint, or indeed become carbon negative within very short time frames.
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Detailed Glycosylation Analysis of Therapeutic Enzymes Utilizing Comprehensive 2D-LC–MSIn this article, the use of comprehensive two-dimensional liquid chromatography (LC×LC) coupled to mass spectrometry (MS) for characterizing glycosylation of therapeutic enzymes is presented.
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The Power of Trypsin Immobilized Enzyme Reactors (IMERs) Deployed in Online MDLC–MS ApplicationsCommercially available trypsin IMERs can digest proteins with high sequence coverage and robustness, facilitating online multidimensional LC–MS.
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The Benefits of Custom Bonded SilicaNot all chromatography resins are created equal. Off-the-shelf chromatography resins might not always meet the rigorous purification requirements of biopharmaceutical manufacturing. Custom bonded silica from Grace can address a wide range of separation challenges, leading to real performance improvements. Discover more about the latest innovations in chromatography silica from Grace, including VYDAC® and DAVISIL®.
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A Study on the Optimization of the Ion-Pair Reversed Phase Liquid Chromatography Analysis of Protected And Unprotected DNA OligonucleotidesThis article describes a comprehensive study on optimizing ion-pair reversed-phase liquid chromatography for analysing protected and unprotected single-stranded DNA oligonucleotides.
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Combined Chromatographic and Spectrometric Approaches for Cleaning Verification of Small-Molecule Pharmaceutical Compounds in the Manufacturing EnvironmentWe assess recent advances in cleaning verification methods for small-molecule pharmaceuticals, and propose a workflow.
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Purification and Isolation of Cannabinoids: Current Challenges and PerspectivesThe current challenges and future perspectives of the purification of cannabinoids from cannabis extracts are presented in this review article.
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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 Intricacies of Oligonucleotide SeparationsPeter Pellegrinelli, Applications Specialist at Advanced Materials Technology (AMT) explains the complexity of oligonucleotide separations due to the unique chemical properties of these molecules. Issues such as varying length, sequence complexity, and hydrophilic-hydrophobic characteristics make efficient separations difficult. Separation scientists are addressing these challenges by modifying mobile phase compositions, using varying ion-pairing reagents, and exploring alternative separation modes like HILIC and ion-exchange chromatography. Due to these complexities, AMT has introduced the HALO® OLIGO column, which offers high-resolution, fast separations through its innovative Fused-Core® technology and high pH stability. Alongside explaining the new column, Peter looks to the future of these separations and what is next to come.
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Rapid Quantitative Analysis of Ethylene Oxide and 1,4-Dioxane in Polymeric Excipients Using SIFT-MSPharmaceutical excipients, such as polyethylene glycol-based polymers, must be tested for the presence of ethylene oxide (EtO) and 1,4-dioxane as part of a safety assessment, according to USP Chapter <228>.
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Online Ion-Exchange Solid-Phase Extraction Cleanup for PFAS in Food of Animal OriginOnline SPE–LC–MS/MS combined with the method presented enabled automated cleanup of food extracts and determination of PFAS compounds in the ng/kg range.
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Liquid Chromatographic Peak Purity Assessments in Forced Degradation Studies: An Industry PerspectiveThis review article discusses scientific rationales and current best practices in the pharmaceutical industry for performing chromatographic peak purity assessments (PPA). These activities are associated with the development and validation of liquid chromatographic (LC) stability-indicating analytical methods applicable to regulatory submissions of small-molecule drug candidates. The discussion includes a comprehensive overview of the PPA-related regulatory and scientific landscape and common industry approaches to obtain PPA results, as well as the strengths and weaknesses of PDA-facilitated ultraviolet (UV) PPA and other PPA techniques.
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Sample Preparation by Electric Field–Assisted ExtractionIntegrating electric fields into extraction techniques increases sensitivity and selectivity. These approaches are compatible with miniaturized, portable, and many biological samples.
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Py-GC-MS Investigation of Pyrolysis Behaviours and Decomposition Products of α- and β-2,7,11-Cembratriene-4,6-DiolsThe study of the thermal behaviour and pyrolysis products of these terpenoids could possibly suggest flavour precursors that could be used to provide specific flavours to tobacco.
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Anomalous Retention Prediction Using Modelling Software in Gradient Reversed-Phase Liquid Chromatography: Why it Can Occur and How to Prevent ItThe success of screening column and mobile phase combinations that generate dissimilar selectivity is highlighted in a typical method development strategy.
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High-Throughput Profiling of Long Chain Fatty Acids and Oxylipins by LC–MSLong chain fatty acids (LCFAs) function as a source of metabolic energy, substrates for membrane biogenesis, and storage of metabolic energy. Oxylipins, oxygenated derivatives of LCFAs, regulate the activity of many cellular processes. Existing methods for the analysis of LCFAs and oxylipins have limited compound coverage and sensitivity that, therefore, prevent their application in biological studies. In this work, we developed a high-throughput LC–MS method for analysis of 51 LCFAs and oxylipins. LCFAs and oxylipins were first extracted from biological samples via solid-phase extraction. The extracted molecules were analyzed by targeted comparative metabolomics. Saturated and monounsaturated LCFAs were analyzed in single ion reaction mode, while polyunsaturated LCFAs and oxylipins were analyzed in multiple reaction monitoring mode. Using this method, we successfully quantified 31 LCFAs and oxylipins from mouse livers.
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Turbulent-Flow LC for LC–MS and LC–MS–MS BioanalysisThis month's "Directions in Discovery" gives a brief overview of turbulent- flow liquid chromatography, a technique for fast separations. Two examples demonstrate the use of the technology for high-throughput bioanalytical separations in drug discovery.
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Method Development for Reversed-Phase Separations of Peptides: A Rational Screening Strategy for Column and Mobile Phase Combinations with Complementary SelectivityThis review article summarizes the results obtained from the combined efforts of a joint academic and industrial initiative to solve the real-life challenge of determining low levels of peptide-related impurities in the presence of the related biologically-active peptide at a high concentration.
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Multivariate Optimization Procedure for Dynamic Headspace Extractions Coupled to GC(×GC)A generalized approach using DoE is presented for the optimization of DHS extraction parameters.
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Tips & Tricks: GPC/SEC Analysis of Aqueous Polymer DispersionsPolymer dispersions are used in numerous applications including paints, binders, and adhesives. These complex mixtures usually contain polymeric components that contribute significantly to their physical and chemical properties.
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A Suitable Therapeutic Drug Monitoring Method for Amoxicillin in Plasma by High Performance Liquid Chromatography–UV (HPLC–UV) in NeonatesThis simple, rapid, and accurate HPLC-UV method can facilitate routine therapeutic drug monitoring in neonates.
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Ion-Exchange Displacement Chromatography: Scale-Up and Displacer Clearance for Recombinant Human Brain-Derived Neurotrophic FactorDisplacement chromatography is a viable alternative to elution chromatography, but the biotechnology industry has yet to fully exploit this technique. The authors present results of a pilot-scale ion-exchange displacement process developed for the removal of variants from recombitant human brain-derived neutrotrophic factor.
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Monitoring for Per- and Poly-Fluoroalkyl (PFAS) with Advanced Mass Spectrometry– Based MethodsPer- and poly-fluoroalkyl substances (PFAS) are a family of potentially thousands of synthetic compounds that have long been used in the manufacture of a variety of common products with stain-repellent and nonstick properties. Their signature strong fluorine and carbon bonds make them difficult to break down and, as a result, they are among the most persistent of today’s environmental pollutants. Alarmingly, PFAS can be found in drinking water and have been shown to accumulate in the body with the potential to cause multiple health problems, such as hormone disruption and cancer. Advances in mass spectrometry have facilitated the detection of known PFAS contaminants as well as the identification of poorly studied and novel compounds in watersheds. This article explores the detection of known and novel PFAS contaminants in aqueous film-forming foams and raw drinking water sources in North Carolina, using new advances in mass spectrometry and data acquisition to improve identification and quantitation.
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Development of Highly Sensitive LC–MS and CE–MS Methods for In-Depth Proteomic and Glycomic Profiling of Limited Biological SamplesBetter sample preparation and miniaturized separations are enhancing these analyses.
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Determination of Polychlorinated Biphenyls in Water Samples Using a Needle Trap Device Combined with Gas ChromatographyThe method presented here, which uses a novel needle trap device (NTD) with sol-gel PEG-coated fibers in conjunction with GC, is a simple, inexpensive, and accurate tool for the analysis of trace levels of PCBs in water samples.
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Nontargeted Screening for the Verification of Allergenic Ingredients and Perfume Authenticity by GC-ecTOF-MSIn this study, the experimental nontargeted screening approach and corresponding data analysis workflows—simultaneously using molecular ion information and structural information—are presented for the molecular identification and authenticity verification process from a brand perfume using GC–ecTOF-MS.
