AUTHOR=Wouters Sam , Pijpers Ils , Vanden Haute Ninon , Meston Daniel , Dillen Lieve , Cuyckens Filip , Eeltink Sebastiaan 

TITLE=Making high salt concentrations for optimal chromatography compatible with electrospray ionization mass spectrometry using an ion exchange membrane suppressor: Analysis of biomarkers for transporter protein inhibition as a case study

JOURNAL=Frontiers in Analytical Science

VOLUME=Volume 2 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/analytical-science/articles/10.3389/frans.2022.1002935

DOI=10.3389/frans.2022.1002935

ISSN=2673-9283

ABSTRACT=This study reports on the potential of using ion-exchange suppressor technology in liquid chromatography - electrospray ionization mass spectrometry workflows. The aim was to overcome the incompatibility of using high salt concentrations to improve separation performance, with electrospray ionization, where this will lead to significant ion-suppression. As a case study, we apply the concept to the hydrophilic interaction liquid chromatography separation and detection of taurine and glycochenodeoxycholate sulfate, endogenous biomarkers for organic anion transporter protein inhibition. The desired chromatographic selectivity was achieved applying 100 mM ion-pairing agent, while ions negatively affecting MS sensitivity were actively removed post-column from the solvent via a charged partially permeable membrane and replaced with protons, resulting in an up to 10-fold increase in detection sensitivity.