Liquid junction coupling for capillary zone electrophoresis/ion spray mass spectrometry

Abstract

A liquid junction coupling has been developed to couple capillary zone electrophoresis (CZE) with ion spray mass spectrometry. The liquid junction was found to compensate for the different eluent flows required by the ion spray liquid chromatograph/mass spectrometer interface and the CZE column. The utility of the CZE/mass spectrometry union is demonstrated by its application to the separation of acid pesticides, sulfonated azo dyes and a tryptic digest of recombinant bovine somatotropin by CZE and detection by mass spectrometry and tandem mass spectrometry. Mass spectrometric detection was carried out in both positive and negative ion modes. Separation efficiencies are shown ranging from 50 000 to 300 000 theoretical plates with peak asymmetries of 1.2–1.8 for the components separated in the tryptic digest.