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Comprehensive Multilevel Characterization of Biologics Using Sheathless Capillary Electrophoresis Hyphenated to Tandem Mass SpectrometryAn analytical methodology for the characterization of the primary structure of biotherapeutic proteins using sheathless CE–ESI-MS-MS instrumentation is presented. For the first time, complete sequence coverage can be achieved using a bottom-up proteomic approach from a single analysis of a tryptic digest. In a biosimilarity assessment, a single amino acid substitution was detected.
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Optimizing MS-Compatible Mobile Phases for IEX Separation of Monoclonal AntibodiesThe impact of ionic strength, buffer capacity, and pH-response on the retention behavior and peak shape of mAb species characterization is evaluated for IEX-MS. The aim of the present study was to understand the impact of ionic strength, buffer capacity, and pH-response on the retention behavior and peak shape of mAb species.
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Advanced Antibody–Drug Conjugate Structural Characterization by Sheathless Capillary Electrophoresis–Tandem Mass Spectrometry Using Complementary ApproachesWith this method, a single injection was sufficient to characterize the amino acid sequence with complete sequence coverage. In addition, glycosylation and drug-loaded peptides could be identified from MS/MS spectra. A drug-loaded peptide fragmentation mass spectra study yielded drug-specific fragments, which reinforced the confidence about the identifications. The results reveal the ability of the sheathless CZE–MS/MS method to characterize an ADC’s primary structure in a single experiment.
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Why and How to Avoid Ionic Contamination in Water Used for LC–MS AnalysesIonic contaminants in the water used in UHPLC analyses with MS detection method lead to adduct formation and reduced analytical signals because of ion suppression. In MS, the preferred ion type is the protonated molecular ion, especially in peptide analysis, since the partially mobile proton charge enables more meaningful fragmentation analysis, as compared to a sodiated peptide ion. Moreover, the occurrence of protonated analyte signals indicates that solvents and reagents, as well as the MS instrument used in analyses, are clean and do not contribute any contaminating cationic components to the analytical process. In the experiments presented here, it was observed that the signal intensities of the protonated species decreased as the sodium ion concentration in the water increased. This was accompanied by an increase in the intensity of sodiated adducts.
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Mass Spectrometry in the Clinical Laboratory—Challenges for Quality AssuranceTo translate the enormous potential of MS into meaningful, actionable, and safe test results in the specific setting of a clinical laboratory is a very substantial challenge. It is essential to realize that reliability is not inherent to this technology but must be addressed carefully and questioned systematically.
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Removal of Contaminant Peaks in Reversed-Phase Gradient Liquid Chromatography for Improved Detection of Pharmaceutical ImpuritiesThis article presents a method for comparing the levels of baseline interference arising from common laboratory mobile phase contamination sources and assesses different approaches for removing dissolved contaminants to generate interference-free chromatogram baselines. The authors demonstrate that recirculating mobile phase through a semi-preparative scale column using a reagent delivery pump has advantages over previously published mobile phase decontamination methods.
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Removal of Contaminant Peaks in Reversed-Phase Gradient Liquid Chromatography for Improved Detection of Pharmaceutical ImpuritiesThis article presents a method for comparing the levels of baseline interference arising from common laboratory mobile phase contamination sources and assesses different approaches for removing dissolved contaminants to generate interference-free chromatogram baselines. The authors demonstrate that recirculating mobile phase through a semi-preparative scale column using a reagent delivery pump has advantages over previously published mobile phase decontamination methods.
Latest:
Removal of Contaminant Peaks in Reversed-Phase Gradient Liquid Chromatography for Improved Detection of Pharmaceutical ImpuritiesThis article presents a method for comparing the levels of baseline interference arising from common laboratory mobile phase contamination sources and assesses different approaches for removing dissolved contaminants to generate interference-free chromatogram baselines. The authors demonstrate that recirculating mobile phase through a semi-preparative scale column using a reagent delivery pump has advantages over previously published mobile phase decontamination methods.
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HPLC Determination of Residual Primary Amine Content in Epoxy-Amine AdductsLC Determination of Residual Primary Amine Content in Epoxy-Amine Adducts
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Quantification of Total w-6 and w-3 Fatty Acids and w-6/w-3 Ratio in Human Serum Using GC-MSThis article demonstrates the superiority of the GC-MS approach over spectrophotometry.
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GC–MS Analysis of Aroma Compounds in Edible Oils by Direct Thermal DesorptionGC–MS Analysis of Aroma Compounds in Edible Oils by Direct Thermal Desorption
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Bisphenol A Evaluation in Baby Feeding BottlesThe monomer bisphenol A (BPA) is used to make polycarbonate plastic and epoxy resins and has been present in many plastic bottles and metal food and drinks cans since the 1960s.
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Avoiding Reversed-Phase Chromatography Problems Through Informed Method Development Practices: Choosing the Stationary-Phase ChemistryUnderstanding the chemistry of embedded polar group and perfluorophenyl phases leads to better decisions during method developement
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Effective Cleanup of Fat Containing Samples in the Analysis of Contaminant ResiduesHigh fat content of foods has been a problem when analyzing samples for nonpolar contaminants such as pesticides, PCBs, and PAHs. Extraction methods for these compounds tend to generate samples that are highly contaminated with fatty matrix, causing a number of problems with the subsequent chromatographic analysis. Traditional cleanup techniques, such as gel permeation chromatography (GPC) and normal phase column chromatography can be very effective, but are often expensive and time consuming. In this seminar, we will present an alternative approach to the cleanup of fats using a novel zirconia-based family of sorbents, for both QuEChERS (dispersive SPE) and traditional cartridge SPE.
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Analysis of Barbiturates in Urine with Agilent 6430 LC–MS–MS and Poroshell 120 EC-C18Toxicology Laboratory at the Veterans Administration, Portland, Oregon, USA, Agilent Technologies
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Advances in Sample Preparation: Removing Phospholipids from Biological SamplesAdvances in Sample Preparation: Removing Phospholipids from Biological Samples
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Advances in Sample Preparation: Removing Phospholipids from Biological SamplesAdvances in Sample Preparation: Removing Phospholipids from Biological Samples
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Future-Proofing Validated Pharmacopeia Methods: A Case Study of Improving Throughput and Decreasing Operational CostHow to modernize an older pharmaceutical monograph from an HPLC column to an UHPLC column, along with calculated time and solvent savings.
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Evaluation of Automated Solid-Phase Extraction for Nitrosamines Using US EPA Method 521Disinfection by-products (DBP) are an ever-present nuisance in the efforts to purify drinking water, wastewater, and municipal waters from various sources.
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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
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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
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Tips & Tricks: Influence of Sample Dispersity on the GPC/SEC Separation of Multi-Component SystemsThis instalment of Tips & Tricks focuses on whether a complete separation can be achieved using GPC/SEC and, if so, under what conditions.
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Separation Science in Drug Development, Part II: High-Throughput CharacterizationThis installment provides an overview of high-throughput characterization techniques of drug leads to support small molecule drug discovery programs in a pharmaceutical company. A myriad of analytical chemistry techniques including separation science methodologies are used to confirm the structures and identities, quantitating the concentrations of stock solutions, and measuring key physicochemical properties of the new chemical entities (NCE). A case study is used here to illustrate the details of these applications in high-throughput characterization.
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Challenges in the Determination of Protein Aggregates, Part IIHere in part II of our series on assessing protein aggregation, we provide an overview of best practices for achieving this goal, including the importance of using a multimethod approach.Here in part II of our series on assessing protein aggregation, we provide an overview of best practices for achieving this goal, including the importance of using a multimethod approach.
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From “Green” to “Sustainable” Sample Preparation in Omics Studies in the Natural Product Field: Case Studies Dealing with Cannabis sativa L.To measure a method’s environmental friendliness and its sustainability, one must consider its productivity and analytical performance.
