With increasing evidence of the important role of peptides in pathophysiological processes, a trend towards the development of highly sensitive bioanalytical methods is ongoing. Inherent to the electrospray ionization process
of peptides and proteins is the production of multiple charge states which may hamper proper and sensitive method development. Supercharging agents allow modifying the maximal charge state and the corresponding distribution of charges, thereby potentially increasing the number of ions reaching the detector in selected reaction monitoring mode. In this study, the use of mixtures of charge state modifying additives, i.e. m-nitrobenzylalcohol (mNBA), sulfolane and dimethyl sulfoxide (DMSO), to specifically increase the abundance of
one charge state of interest has been investigated. Screening experiments were performed to define an experimental domain, which was then further investigated via a response surface design to predict the optimal
combination and concentration of superchargers. Using a combination of mNBA and DMSO (0.008% and 0.5% m/v respectively), we were able to increase the abundance of the +4 charge state of the investigated peptide neuromedin U from 64% to 87%. Unfortunately, charge state coalescence did not result in repeatable sensitivity improvements in this case study. However, it remains an attractive approach during method development of peptide bioanalytical methods, as coalescence to a particular intermediate charge state is difficult to obtain by using only one supercharging agent.
Original languageEnglish
Pages (from-to)206-214
Number of pages9
JournalTalanta
Volume198
DOIs
Publication statusPublished - 2019

    Research areas

  • Charge state, Electrospray ionization, NanoUHPLC-MS/MS, Neuromedin U, Peptide, Superchargers

ID: 44104236