A one-step sample pretreatment and loading method for complex sample separation with supercritical fluid chromatography

Abstract

Solvent mismatches as well as impurity interference have become obstacles for supercritical fluid chromatography (SFC). In this study, a one-step sample pretreatment and loading method was developed for separation of Hedyotis diffusa (H. diffusa) with SFC. H. diffusa was firstly mixed with C18-bonded silica, and then subjected to a loading device, which was in line with a SFC column. Non-targeted components were firmly retained on C18-bonded silica in the condition of 100% CO2 at a flow rate of 15 mL/min for 10 min, while targeted fractions were eluted to the SFC column, where the targets were enriched and then separated. Thus, a one-step pretreatment and direct loading of target components were achieved with the use of chromatographic material, which in turn solves the issue of solvent incompatible as well as co-existing impurities. Finally, a rapid and effective SFC separation of the targets in H. diffusa was achieved with sharp peaks.