Evaporative Light Scattering Detection for Supercritical Fluid Chromatography

Abstract

A high-performance liquid chromatograph-evaporative light scattering detector is modified and interfaced with a supercritical fluid chromatograph. The detector performance is evaluated by monitoring the response of several steroids. Specifically the effects of nitrogen makeup gas flow rate, carbon dioxide modifier type, modifier concentration, evaporative light scattering detector orifice size, and detector temperature are determined. As the nitrogen gas flow rate increases, the response of the analyte decreases, but the increased flow improves peak shape to mimic that obtained with ultraviolet detection. Furthermore, increasing the detector temperature causes the response of the analytes to decrease. A detection limit of 10 ng or less is determined for progesterone and testosterone with 2% and 20% (v/v) methanol-modified carbon dioxide on a Deltabond cyano column (4.6 mm × 15 cm, 5 µm) at 150 mL/min and 1000 mL/min decompressed carbon dioxide. The separations of polyethylene glycols and ginko biloba leaf extract with the optimized conditions