Capillary‐zone electrophoresis with fraction collection for desorption mass spectrometry

Abstract

Abstract A simple method for off‐line coupling of desorption mass spectrometry and capillary‐zone electrophoresis (CZE) is described. Use of a “porous glass joint”, near the cathodic end of the CZE column, facilitates fraction collection in a manner similar to that used with liquid chromatography. This method allows independent optimization of both the CZE and mass spectrometry parts of the experiment. It is directly applicable to a number of desorption mass spectrometry methods (including plasma desorption (PD) and UV laser desorption (LD)). In the present study, PD mass spectrometry was used for eluant characterization. The fraction collection procedure is described, as is mass transfer through the porous glass joint. Detection limits are discussed and the approach is illustrated by analysis of a simple mixture of bradykinin derivatives. Finally, a brief comparison to current on‐line CZE/mass spectrometric methods is presented.