The particle beam interface aided with particle forming solvent was evaluated for packed column supercritical fluid chromatography-mass spectrometric coupling. Fundamental studies on the effects of various operational parameters were undertaken. Factors influencing aerosol formation (nebulizing capillary I.D., particle solvent type and flow-rate) were evaluated. Pure CO 2 and methanol-modified CO 2 were utilized with equal success. The sensitivity of the system was evaluated in terms of limit of detection (LOD). The electron impact scan and single ion monitoring modes were determined to be 10 and 1 ng for caffeine, respectively. These LODs are 10 to 100 times better than previous reported estimates. Separations of carbamate pesticides and polyaromatic hydrocarbons are shown as examples of the system's utility. Electron impact spectra were artifact-free and comparable to on-line library spectra.