PACKED-COLUMN SUPERCRITICAL-FLUID CHROMATOGRAPHY MASS-SPECTROMETRY WITH PARTICLE-BEAM INTERFACE AIDED WITH PARTICLE FORMING SOLVENT

The particle beam interface aided with particle forming solvent was ev aluated for packed column supercritical fluid chromatography-mass spec trometric coupling. Fundamental studies on the effects of various oper ational parameters were undertaken. Factors influencing aerosol format ion (nebulizing capillary I.D., particle solvent type and flow-rate) w ere evaluated. Pure CO2 and methanol-modified CO2 were utilized with e qual success. The sensitivity of the system was evaluated in terms of limit of detection (LOD). The electron impact scan and single ion moni toring modes were determined to be 10 and 1 ng for caffeine, respectiv ely. These LODs are 10 to 100 times better than previous reported esti mates. Separations of carbamate pesticides and polyaromatic hydrocarbo ns are shown as examples of the system's utility. Electron impact spec tra were artifact-free and comparable to on-line library spectra.