Alkaloids analysis using off-line two-dimensional supercritical fluid chromatography × ultra-high performance liquid chromatography

Abstract

In this study, an off-line two-dimensional (2-D) supercritical fluid chromatography (SFC) × ultra-high performance liquid chromatography (UHPLC) method with high orthogonality was developed for the analysis of the practical amide alkaloids fraction from P. longum L. The effects of SFC parameters such as column type, organic modifier, temperature and back-pressure on separation were systematically evaluated. Different selectivity was observed for different columns (BEH, BEH 2-EP, XAmide and CSH FP). An investigation was then carried out of the orthogonality of different columns and systems following a geometric approach with a set of amide alkaloid samples. The orthogonality between a CSH FP column and a BEH column reached 50.79%, which was much higher than that for the other columns. While the orthogonality between SFC and UHPLC based on an XAmide column and an HSS T3 column reached 69.84%, which was the highest of all the combinations. At last, the practical amide alkaloids fraction was analyzed with an off-line 2-D chromatography SFC × UHPLC system. In total, at least 340 peaks were detected by this method. Rapid separation in these two dimensions and easy post treatment of SFC facilitated this 2-D system for the separation of complex samples.

Liquid chromatographic separation of alkaloids in herbal medicines: Current status and perspectives

“…[80]. The combined SFC and UHPLC was applied in the analysis of the amide alkaloids fraction from the fruits of Piper Longum L. [81]. Rapid separation achieved with this 2D‐LC method and convenient posttreatment of SFC were two main advantages for the separation of complex samples.…”

Supercritical Fluid Chromatography in Natural Product Analysis – An Update

“…The separation of the amine alkaloids in Piper longum was reached through the offline coupling of SFC and UHPLC [50]. The first dimension was performed on a SFC system using a XAmide column and methanol as modifier.…”

Purification of lignans from Fructus Arctii using off‐line two‐dimensional supercritical fluid chromatography/reversed‐phase liquid chromatography

“…For instance, Li et al. developed an off‐line 2D SFC × UHPLC using XAmide and HSS T3 columns to separate the alkaloids. Thanks to the different separation mechanisms, the method has properties of high orthogonality and fast analysis speed.…”