High efficiency columns increase resolution by reducing peak widths. This enables easier peak integration and identification, as the peaks of interest are better separated from each other and from potential background or excipient peaks. There are several ways for an analyst to improve separation efficiency; one being to use columns packed with smaller particle size stationary phases. Another way is to use longer columns. However, a drawback in the use of both options is that they can be limited by the system operating pressure. Another path forward is the use of solid-core or superficially porous particles (SPP), which have been proven to improve efficiency without sacrificing operating pressure. This app note shows incremental steps on how to improve separation efficiency for a mixture of three analytes.
Inside the Laboratory: Measuring Molecular Tracers of Emerging Aerosol Sources
October 14th 2024Inside the Laboratory is a joint series with LCGC International and Spectroscopy, profiling analytical scientists and their research groups at universities all over the world. This series spotlights the current chromatographic and spectroscopic research their group is conducting, and the importance of their research in analytical chemistry and specific industries.
Top-down characterization of engineered Bcl-xL proteoforms
October 11th 2024Top-down fragmentation enables rapid characterization of phosphorylated proteins without extensive sample preparation and digestion. In this study, electron capture dissociation (ECD) was used to fragment proteoforms of the cell death-related protein, Bcl-xL. Using these methods, 85–90% sequence coverage was achieved for Bcl-xL proteoforms, allowing for effective localization of phosphorylation within minutes.
Antibody peptide mapping using the new Agilent ExD cell
October 11th 2024Enhanced antibody analysis using electron capture dissociation (ECD) allows for precise glycan localization in low-abundance glycopeptides. This study compares the fragmentation of trastuzumab tryptic digests using ECD and collision-induced dissociation (CID). While CID generates abundant glycan HexNAc ions at 204 m/z, ECD preserves the labile glycan group, enabling accurate site localization.