ELUENT JET INTERFACE FOR COMBINING CAPILLARY LIQUID FLOWS WITH ELECTRON-IMPACT MASS-SPECTROMETRY

A new interface based on an eluent jet in combination with a conventio nal gas chromatography momentum separator for use with electron impact mass spectrometry is described. The formation of the eluent jet is ba sed on radio frequency inductive heating. The aerosol formation in the ; interface is discussed in relation to commercial particle beam (PB) interfaces. The interface is tested in combination with electron impac t mass spectrometry using flow injection analysis at now rates in the range of 5-15 mu L/min commonly encountered in microcolumn liquid chro matography. Electron impact spectra at 1-10-ng levels are found to be comparable with reference spectra. In the single-ion mode, 50 pg of ca ffeine is detectable with a signal-to-noise ratio of 3:1. Contrary to many other PB systems, linear calibration plots are obtained in the te sted range of 3-200 ng of caffeine.