Design and construction of an interface for direct liquid introduction coupling of a microbore high-performance liquid chromatograph to a quadrupole mass spectrometer

Abstract

Recently various efforts have been made to transfer the compounds separated by high-performance liquid chromatography into the ion source of a mass spectrometer. One development in such interfacing is the on-line direct liquid introduction of the column effluent. In this paper we describe the design and construction of a splitless micro-high-performance liquid chromatography-mass spectrometry interface which allows the unrestricted flow of the eluent and jet-formation directly into the ion volume of a quadrupole mass spectrometer. The use of a water-cooling, laser-punctured orifice or diaphragm at the probe tip was not necessary in our experiments. The desolvation of the mobile liquid phase in the transline, an open glass capillary, is controlled only by the selected parameters for ion source temperature, the flow-rate of the chromatographic pump and by the high vacuum of the mass spectrometer. Tests on different transline materials have been carried out and the results are discussed; applications and mass spectra obtained by this procedure are presented.