IONIC LIQUID-BASED DISPERSIVE LIQUID-LIQUID MICROEXTRACTION FOLLOWED BY HPLC FOR THE DETERMINATION OF SIX EFFECTIVE COMPOSITION OF Silybum marianum

Abstract

A novel pretreatment method ionic liquid-based dispersive liquid-liquid microextraction followed by high-performance liquid chromatography (HPLC) was established and applied in the analysis of silychristin, silydianin, silybin, silybin B, isosilybin A, isosilybin B in Silybum marianum. The critical parameters affecting dispersive liquid-liquid micro-extraction (DLLME), including selection of dispersive solvent and extraction solvent, volume of dispersive solvent and extraction solvent, adjustment of pH, salt concentration, extraction time, were investigated by single factor study. Under optimum conditions, all of the target analytes presented good linearity (r > 0.9991) and satisfied recoveries (recoveries > 89.5%, relative standard deviation (RSD) < 4.6%). The limits of detection and quantification were 0.16 to 0.74 ng kg^–1 and 0.42 to 2.52 ng kg^–1, respectively. The developed method is sensitive, rapid, accurate and employable to simultaneously determine six target compounds in Silybum marianum.

Keywords:
ionic liquid; dispersive liquid-liquid microextraction; HPLC; Silybum marianum; seed