Development of supercritical fluid extraction coupled to comprehensive two-dimensional supercritical fluid chromatography (SFE-SFCxSFC)

Supercritical fluid extraction was coupled to comprehensive two-dimensional supercritical fluid chromatography with conventional packed columns. With this system, three modes of operations were feasible, such as SFE-SFC, SFCxSFC, and SFE-SFCxSFC. The operations for valve switching and data acquisition were automated using in-house software. In order to evaluate the present system, SFE-SFC for polymer additives in polypropylene, SFCxSFC for a mixture of benzene derivatives with different polarities, and SFE-SFCxSFC for styrene oligomers in polystyrene were performed. With SFE-SFCxSFC, diastereomers were resolved for linear tetramers and pentamers as well as trimers with the tetraline moiety.