Preparation Of Molecular Imprinting - Solid Phase Microextraction Extractor And Its Application In Estrogen Analysis In Food

This paper reports a novel molecularly imprinted polymer (MIP) coated fiber for estrogens, a method combining the SPME with high performance liquid chromatography-ultraviolet (HPLC-UV) was used for the determination of micro-trace level of estrogen in food. The MIP coated fiber was fabricated using silica fiber as substrate. A rationally designed 17-ethylestradiol (ED) that exhibits resemblance to estrogens has been synthesized and used as pseudo template, which effectively solved the template leakage of the traditional molecular imprinting. A DFT-based computational simulation method was proposed to choose the best functional monomer and porogen, and we select 2-(trifluoromethyl) acrylic acid (TFMAA) and acrylic acid (AA) as composite functional monomer which enhanced the adsorption capacity and selectivity. Scanning electron microscopy showed that the surface of SPME coating which was compact and uniform. The heterogeneity and adsorption property of MIP coating were modeled with the Freundlich isotherm equation, the experiment demonstrated that the SPME coating had a high adsorption capacity and selectivity. The kinetics study showed the fast adsorption and desorption capacity. A method, for determination of estrogens in milk powder samples, combining molecularly imprinted solid phase micro-extraction (MISPME) with high performance liquid chromatography-ultraviolet (HPLC-UV) was developed. The limits of detection were in the range of 0.83-2.5 ng mL-1, the recoveries were 86-92%,88-97%,90-93% and 95-99% with RSD<6.7% for estrone, 17β-estradiol, estriol and 17-ethynylestradiol, respectively. With the advantages of high recoveries, good accuracy, simple, rapid and efficient, this method was reliable for the analysis of estrogen.