ABSTRACT
Most Supercritical Fluid Chromatography SFC/Mass Spectrometry (MS) interfaces were originally designed for SFC/MS or liquid chromatography (LC)/Mass Spectrometry (MS) and were modified for the special requirements of SFC/MS. Many of the high-flow-rate interfaces are modified versions of commercial LC/MS interfaces. The mobile-phase-elimination or "transport" interfaces are designed to increase the ratio of analyte to mobile phase entering the ionization region. A portion of the effluent is split after the expansion step, but before the ionization region, in what people consider "post-expansion-splitting" interfaces. The column effluent is introduced directly to the ion source when the direct-fluid-introduction interface is used for open-tubular or packed-capillary SFC/MS. A good deal of effort has been devoted to the interfacing of SFC to plasma ionization-mass spectrometry. Though compatible with packed-column flow rates, the heated nebulizer/atmospheric pressure chemical ionization interface has most frequently been used for open-tubular SFC/MS.
