SAMPLE INTRODUCTION AND ELUTION METHOD FOR PREPARATIVE SUPERCRITICAL FLUID CHROMATOGRAPHY

The loading capacity in preparative supercritical fluid chromatography with different injection and elution methods was investigated. With the ordinary valve injection method using a syringe, the maximum loading capacity onto a column (250 mm × 10 mm I.D.) packed with 5-μm silica gel was only a few milligrams. However, this value was increased by a factor of ten (a few hundred milligrams) for a column (125 mm × 10 mm I.D.) packed with 10-20 μm silica gel using a programmed extraction-elution method employing a small extraction vessel (1 ml) connected to the column and stepwise pressure gradient elution. © 1990.