ABSTRACT
The introduction of electrospray and matrix-assisted laser desorption ionization in the 1980s has successfully addressed the transfer of ions from biological molecules such as proteins to the gas phase. These ionization processes have offered an entirely unexplored field to mass spectrometry (MS), represented by the analysis of biological compounds and/or samples. Concomitantly, the analysis of intact proteins has demonstrated a growing interest in various research fields such as the study of non-covalent complexes and the characterization of biopharmaceutical products. Intact proteins represent complex macromolecules with an extended range of potential heterogeneities. The coupling of high-resolution capillary electrophoresis separations with high-sensitivity and selectivity MS detections represents a relevant approach for targeted or comprehensive analyses of intact proteins. A special attention is therefore paid to adjust the composition of the additional liquid to obtain the best performances. Liquid junction interfaces retain some of the characteristics of sheath-liquid interfaces.
