ONLINE REVERSED PHASE LIQUID CHROMATOGRAPHY-MASS SPECTROMETRY

The addition of a modified segmented-flow extractor between a liquid chromatograph (LC) and a mass spectrometer (MS) permits the direct coupling of an LC, operated in the reversed phase mode, to an MS without compromising the operational characteristics of either. This combination is accomplished by the extraction of solutes into a volatile organic solvent, which is then transported into the MS via a moving belt interface. The system has been tested with a mobile phase consisting of 40-60 (v/v) MeOH-H2O, 0.1 M NaH2PO4, pH 2.5 at a flow rate of 0.5 mL/min and was operated for a significant period of time with no deterioration of the performance of the MS. The applicability of the interface to the analysis of carbamate pesticides has been examined. The effects of the interface on peak broadening and sample recovery have also been examined. This system provides a means of performing reversed phase liquid chromatography, even with nonvolatile buffers, in an on-line combination with an MS. © 1979, American Chemical Society. All rights reserved.