Preparation of molecularly imprinted polymers coupled with high-performance liquid chromatography for the selective extraction of salidroside from Rhodiola crenulata.

Salidroside is one of the bio-active compounds found in Rhodiola crenulata. To find an easy, time saving and efficient way to extract, purify and enrich salidroside from Rhodiola and other natural plants, we prepared a highly selective molecularly imprinted polymer (MIP) for extraction and preconcentration of salidroside using salidroside (SD) as a template, acrylamide (AM) as a functional monomer, ethylene glycol dimethacrylate (EDMA) as a crosslinking monomer, and dimethyl formamide (DMF) as a porogen. The performance of the MIPs was evaluated through selective recognition capacity and adsorption isotherms and kinetics. The results showed that MIPs possessed excellent specific recognition toward SD and could effectively discriminate its structural analogue. The application of the developed MIPs as a selective sorbent for solid-phase extraction (SPE) of SD was also investigated. Under the optimum conditions, a rapid, economical, and efficient method based upon MIP-SPE coupled with high-performance liquid chromatography (HPLC) was developed for the determination of SD in Rhodiola crenulata. The method showed satisfactory recoveries (from spiked real samples at 3 fortification levels of 0.5, 1 and 10 mg L-1) of 88.74%- 97.64% with relative standard deviations (RSDs) ranging from 2.05%-3.54%. Furthermore, MIP-SPE was successfully used to separate and purify SD from different parts in Rhodiola crenulata and it should be available for determination of salidroside in others herbs.