Separation and determination of alkylamides from prickly ash powder using molecularly imprinting technique

In this work, a molecularly imprinted polymer solid phase extraction method was developed to extract Zanthoxylum alkylamides from prickly ash. Surface molecularly imprinted polymers (SMIP) were prepared using the molecular structural analogs of sanshool as a dummy template molecule and acylated silica as backbone. The structural characteristics of the polymers were determined by Fourier-transform infrared spectroscopy and scanning electron microscopy. Dynamic adsorption and isothermal adsorption were investigated. SMIP was used to prepare a molecularly imprinted solid-phase extraction column (SPEC) for the extraction of Zanthoxylum alkylamides from prickly ash powder, followed by high performance liquid chromatography (HPLC) determination. Through separation by SMIP-SPEC, the purity of alkylamides in prickly ash extracts increased from 27.26%-93.58 %. Good linearity for alkylamides standard solution was obtained in the range of 1.0-800.0 mu g/mL, and low detection and quantification limits were 0.044 and 0.147 mu g/mL, respectively. The method recoveries at four concentration levels of alkylamides were found within 90.3-97.1 % with relative standard deviations (RSDs) of 2.5%-5.9%. These indicate the good recognition ability and affinity to Zanthoxylum alkylamides of SMIP and the novelty of the method for the extraction of alkylamides. The method described could be used for the enrichment of alkylamides and rapid detection.