Quick Supramolecular Solvent-Based Microextraction Combined with Ultra-High Performance Liquid Chromatography for the Analysis of Isoflavones in Soy Foods

摘要

A simple, sensitive, rapid, and economic method was developed for the quantification of isoflavones (daidzein, genistein, biochanin A, glycitin) in soy foods using supramolecular solvent (SUPRAS)-based microextraction combined with ultra-high performance liquid chromatography-ultraviolet detection (UHPLC-UV). Several conditions affecting SUPRAS-based microextraction efficiency, for example amount of decanoic acid, percentage of tetrahydrofuran (v/v), SUPRAS volume, and extraction time, were investigated and optimized. The chromatographic separation of the target analytes was performed with a core-shell analytical column using 0.05 % trifluoroacetic acid in water and acetonitrile in gradient elution mode. Under the optimal conditions, the detection limits of isoflavones in flour samples were reported to be 0.7 mu g g(-1). The linear dynamic range of isoflavones is 0.7-33 mu g g(-1). The recoveries obtained for isoflavones were from 90.3 to 105 %, and concentration factors were between 381 and 410. Finally, the proposed method was applied to determine the concentrations of isoflavones in a variety of commercial soy foods and dietary supplements.