Mass Spectrometry

May 01, 2017
Special Issues
In this study, a simple method was used for extraction and concentration of trace organic compounds in water, followed by injection using a coiled wire filament and GC–MS analysis. Common semivolatile organic compound contaminants at low parts-per-billion levels were detected in less than 10 min.
May 01, 2017
Special Issues
With computational chemistry, chemists can now study chemical phenomena by performing computationally intense calculations on computers rather than examining reactions and compounds experimentally. This is especially attractive when the laboratory experiments are time consuming, costly, dangerous, or difficult. Modern computational chemistry tools are capable of determining molecular structures, molecular spectra, and energetics, and of elucidating reaction pathways and chemical reaction products.
Mar 02, 2017
Sponsored Content
In this Tech Note, CESI-MS was used to characterize and compare a marketed reference mAb with biosimilar candidates. A single injection of each digested mAb provided PTM hot-spot detection (deamidation, Asp isomerisation, etc), glycosylation site mapping and 100% Sequence coverage. This allowed a rapid assessment of candidate biosimilars for continued development.
Mar 01, 2017
Special Issues
The isotopic profile of a material refers to the ratios of the stable isotopes of elements contained within, such as 2H/1H, 13C/12C, and 18O/16O. Biological, chemical, and physical processes cause variations in the ratios of stable isotopes; analysis of a material for its distinctive isotopic signature can thus be used to reveal information about its history. Isotope ratio mass spectrometry (IRMS) is a technique used to measure the relative abundance of isotopes in materials. Forensic investigators have used IRMS to measure a variety of materials, such as drugs, explosives, food, and human remains. In a recent web seminar, Lesley Chesson, the president of IsoForensics, Inc., explained how IRMS works and discussed the use of IRMS in forensic science, illustrating her discussion with several case examples.
Mar 01, 2017
Special Issues
With 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.
Mar 01, 2017
Special Issues
When adhering to sound analytical principles, the inclusion of mass spectrometry in the clinical laboratory can lead to accurate, selective, and precise quantitative methods by detecting new classes of compounds with greater efficiency and sensitivity than is possible with older, established technologies.
Mar 01, 2017
Special Issues
A new peptide mapping method was developed specifically for mAb characterization that employs optimal enzyme pH for robustness, but with short digestion times and time-course elements to minimize and monitor deamidation–isomerization, respectively, enabling a more accurate assessment of potential CDR sequence liabilities.
Jan 01, 2017
LCGC North America
This accurate, precise method overcomes matrix interference problems
Jan 01, 2017
LCGC North America
Clustering is particularly useful for diverse sample sets.
Dec 01, 2016
LCGC North America
Tips for choosing the ionization technique and polarity, tuning key parameters such as ESI source voltages, flow rates, and temperature, and optimizing SRM conditions.
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