An Electrochemical Cell for On-Line Electrochemistry/Mass Spectrometry

Abstract

A new electrochemical flow-through cell has been developed for on-line electrochemistry/mass spectrometry (EC/MS) that allows easy access to the working electrode for resurfacing or replacement and that can withstand back pressures of ∼2000 psi. Simple off-line hydrodynamic electrochemical methods have been developed to determine the cell conversion efficiency. The methods can be used to determine the number of moles of analyte transferred from the cell to the LC/MS interface and thereby estimate the sensitivity in on-line EC/MS. The results that have been obtained show that the mobile-phase composition may influence the cell conversion efficiency. The highest conversion efficiency in the flow-through cell (∼32%) was obtained using 90/10 CH3OH/H2O as the mobile phase, while the lowest conversion efficiency (∼1.8%) was observed with an aqueous mobile phase. Using different mobile phases, the electrochemical flow-through cell was tested in thermospray and particle beam (PB) EC/LC/MS. Conversion efficiencies...