PACKED-COLUMN SUPERCRITICAL-FLUID CHROMATOGRAPHY WITH 220000 PLATES

Up to 250 000 plates and 298 plates/s were simultaneously observed in nonprogrammed packed column supercritical fluid chromatography. Up to 400 000 or even 667 000 plates appear possible. In programmed runs, substantially higher apparent efficiencies were observed. These results were obtained in spite of repeated assertions in the literature that efficiency in packed column supercritical fluid chromatography has a practical upper limit of 20 000 theoretical plates. The simultaneous high efficiency and high speed appear to substantially exceed all previous reports using packed columns and dense fluids.