Development of a supercritical fluid chromatography high-resolution separation method suitable for pharmaceuticals...

A method has been developed for the analysis of a broad spectrum of pharmaceuticals using packed column supercritical fluid chromatography (pSFC) on a cyanopropyl silicagel stationary phase. Five 25 cm x 4.6 mm I.D., 5.0 microm columns were coupled to generate ca. 100000 plates. The selectivity was tuned by varying the nature and concentration of various modifiers and additives in the carbon dioxide mobile phase. It was noted that pressure influences both efficiency and selectivity of the chromatographic process. Final method conditions are: outlet pressure 100 bar, flow 2.0 mL/min, temperature 40 degrees C, organic modifier program from 5% (1 min) to 40% at 2.0%/min, organic modifier composition methanol:acetonitrile in a ratio of 3:1 (variable according to sample composition) with peak symmetry additives trifluoroacetic acid and diisopropylamine both at levels of 0.5%.