Fast analysis of indole alkaloids from Evodiae fructus by supercritical fluid chromatography

Abstract

A fast chromatographic separation of indole alkaloids from Evodiae fructus was developed by supercritical fluid chromatography (SFC). The initial screening of four stationary phases was investigated with a standard mixture of evodiamine and rutaecarpine, and a complex sample of indole alkaloids prepared from Evodiae fructus as probes. Later, the effects of chromatographic parameters on separation were studied including injection volume, organic modifier, additive, temperature and back pressure. The injection volume had significant impact on the peak shape. With the additives in the mobile phase, slight changes in peak shape and retention time were observed in separation. Variation in organic modifier led to dramatic change in chromatographic behavior. Both decreased temperature and increased back pressure shortened the retention time. Finally, a fast analytical method using SFC, on a Waters ACQUITY UPC2 BEH column, methanol as modifier, under 35 degrees C and 2.07 x 10(7) Pa, was developed to separate a complex sample of indole alkaloids in less than 15 min. Another rapid approach for the separation of a complex sample of indole alkaloids was developed by using ultra-high performance liquid chromatography (UHPLC). As a result, SFC can be used in the separation of natural products, giving high performance, good resolution and fast analysis speed. The difference in selectivity with UHPLC can be used to the development of natural product separation.