Simple and selective extraction of quercetin with MEPS method using modified glass powder by a molecularly imprinted polymer followed by spectrophotometric determination

Abstract

A new sample preparation method based on microextraction in packed syringe (MEPS) was developed for preconcentration of quercetin prior to its spectrophotometric determination. Molecularly imprinted polymers (MIPs) as packing material was used for higher extraction efficiency. First, Glass powder as support material because of low-cost and available substrate were modified and then MIPs synthesized by the sol-gel method using 3 aminopropyltriethoxysilane (APTES) as a functional monomer and tetraethyl orthosilicate (TEOS) as cross-linker. The combination of a molecularly imprinted polymers (MIPs) and microextraction in packed syringe (MEPS) increased the selectivity and sensitivity. The surface morphology and functionality of the prepared MIPs was characterized using Fourier-transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM) and Thermogravimetric analysis (TGA). Different influencing parameters on extraction efficiency such as effect of the number of sample sorption/desorption cycles, type and volume of desorption solvent, pH of the sample solution and MIP amounts were optimized. Under the optimum condition, the proposed method displayed a linear range from 0.01 to 5 μg mL-1 and detection limit of 3.68 ng mL-1. Relative standard deviations (RSD) for 3 replicate determination of 1 μg mL-1 quercetin was 2.1 %. The proposed method was applied successfully for the selective extraction of quercetin from tea and coffee samples.