Rational approach to solvent system selection for liquid–liquid extraction–assisted sample pretreatment in counter–current chromatography

• DOI: 10.1016/j.jchromb.2017.04.013
• Publication Date: 2017-04-04T16:44:59Z
• Authors: Jiajia Wang; Dongyu Gu; Miao Wang; Xinfeng Guo; Haoquan Li; Yue Dong; Hong Guo; Yi Wang; Mengqi Fan; Yi Yang
• Keywords: Liquid–liquid extraction; Sample (material); Sample Preparation

A rational liquid-liquid extraction approach was established to pre-treat samples for high-speed counter-current chromatography (HSCCC). n-Hexane-ethyl acetate-methanol-water (4:5:4:5, v/v) and (1:5:1:5, v/v) were selected as solvent systems for liquid-liquid extraction by systematically screening K of target compounds to remove low- and high-polarity impurities in the sample, respectively. After liquid-liquid extraction was performed, 1.4g of crude sample II was obtained from 18.5g of crude sample I which was extracted from the flowers of Robinia pseudoacacia L., and then separated with HSCCC by using a solvent system composed of n-hexane-ethyl acetate-methanol-water (1:2:1:2, v/v). As a result, 31mg of robinin and 37mg of kaempferol 7-O-α-l-rhamnopyranoside were isolated from 200mg of crude sample II in a single run of HSCCC. A scale-up separation was also performed, and 160mg of robinin with 95% purity and 188mg of kaempferol 7-O-α-l-rhamnopyranoside with 97% purity were produced from 1.2g of crude sample II.