Synthesize Characteristics Of Molecularly Imprinted Polymer For Estradiol And Its Application In Food Detection

Estrogens which may be residual in animal foods possess potential influence to human health. The residual of estrogens can disturb the balance of hormone, lead to women’s menopausal disorders, cause lower fertility, girls’precocious puberty and feminization of men. Meanwhile it has strong carcinogenic and teratogenic effects. The residual quantity of estrogens in the milk belongs to trace levels, so we established the methods of combination of molecularly imprinted solid phase extraction and high performance liquid chromatography and molecularly imprinted solid phase extraction and spectrophotometric spectrophotometry to overcome the detection of residual estradiol. Contrast to traditional methods, this method possess higher sensitivity and provide an effective method for the detection of trace estradiol in milk.1. Herein we used estradiol as the template molecules,3-aminopropyl triethoxysilane as the functional monomer, tetraethoxy silane as a crosslinking agent, then utilized the method of combination of surface molecular imprinting technique and the sol-gel technology to synthesis molecularly imprinted polymers which have selective recognition ability to estradiol. The results demonstrate that:different polymerization conditions can affect the adsorption and identification characters of imprinted polymer. Acetonitrile as solvent, when the molar ratio of template, functional monomer and cross linker is1:8:8and the reaction temperature is60℃, the imprinted polymers possess optimal selectivity and adsorbability. Adsorption experiment results dedicated that the saturated adsorption capacity Qmax of estradiol imprinted polymers is30.437mg/g, however non-imprinted polymers is10.383mg/g.The synthesis of molecular imprinted polymers were used as adsorption materials, we established the method of combining molecularly imprinted solid phase extraction and high performance liquid chromatography, the recovery of estradiol in milk samples in three different concentrations (2mg/L,4mg/L and6mg/L) was92.1%-98.4%. This experiment provides a new adsorption material for the detection of trace residues of estradiol in animal foods and this method is simple, accurate, and can satisfy the demands of trace residues in veterinary drugs.2. We used the tetraethvl rhodamine fluorescence estradiol as the template molecule,3-aminopropyl triethoxysilane as the functional monomer, and tetraethoxysilane as a crosslinking agent, and then utilized the method of combination of surface molecular imprinting technique and the sol-gel technology to synthesis fluorescent molecularly imprinted composite microsphere of estradiol. Adsorption experiment results dedicated that maximum adsorption capacity Qmax of estradiol fluorescent molecules imprinted composite microspheres is28.052mg/g, however non-imprinted polymers is10.383mg/g.The synthesis of estradiol fluorescent molecularly imprinted composite microsphere was used as adsorption material, and then we established the method of combining molecularly imprinted solid phase extraction and spectrophotometric method. The recovery of estradiol in milk samples in three different concentrations (2mg/L,4mg/L and6mg/L) was91.8%-96.5%.Maximum adsorption capacity, the recovery rate and the lowest limit of detection of the molecularly imprinted polymer with a single estradiol synthesis as a template have higher sensitivity than tetraethyl rhodamine labeled estradiol as the template synthesis of molecularly imprinted composite microspheres, but the latter sensitivity still can satisfy the national standard (GBT22967-2008), meanwhile need less time and effort contrast to the former.