Synthesis Of The Copolymer Of Graphene And Methyl Methacrylate And Its Application To Solid Phase Extraction Of Phenolic Estrogens

Solid-phase extraction（SPE）is widely applied in sample pretreatment,and the adsorbent material is the core of this technology,so developing new adsorbent materials is a focal point in the field.Graphene is attracted more and mord attention in SPE in virtue of its excellent performance.Herein,we studied the synthesis,characterization and real application of a new SPE material based on poly（methyl methacrylate-graphene）.The main content of research includes three aspects as follow.1.Synthesis of copolymer of graphene oxide and methyl methacrylate(P_GO-MMA)and its reduction(P_GO-MMA)The suspension polymerization,dispersion polymerization and precipitation polymerization were inverstigated,respectively.The precipitated polymerization method was been screen out to obtain a black product with high degree of copolymerization of graphene and methyl methacrylate.The product was further reacted with hydrazine/ammonia to obtain graphene and methyl methacrylate copolymer.Optimized proportion of prepolymer components was achieved.IR spectrum indicated that graphene and methyl methacrylate was copolymerized effectively.Scanning electron microscope image showed lamellar microstructure,and polarizing microscope showed the particle size ranging 10⁵0μm.In several conventional solvents including methanol,ethanol,acetonitrile,acetone and N,N-dimethylformamide,the swelling degree was very small,this indicated its good stability in these solvent.The products were filled in columns with good permeability.The two resulted products in this chapter would be applied to subsequent SPE.2 P_GO-MMA material was applied to the extraction of bisphenol A（BPA）in water sample and detected by HPLC.Optimized SPE conditions.The proposed method was applied to the analysis of BPA of SiYu Lake water located on the campus of Fujian Medical University.Satisfactory spiked recoveries 82.4%¹15%were obtained,the RSD%was less than 14.9%（n=3）.By comparison of related materials including P_GO-MMA,P_Gr-MMA,P_MMA and C₁₈ column for SPE,the results showed that the extraction ability of the first two were better than P_MMA and C₁₈ column,indicating that graphene/graphene component improving adsorption performance obviously.In addition,the extraction capacity of P_GO-MMA to BPA was better than that of P_Gr-MMA,it was because that the hydroxyl groups in P_GO-MMAO-MMA material could produce hydrogen bonds with BPA molecules to enhance the adsorption capacity.Experimental results show that P_GO-MMAO-MMA material could be effectively applied to extraction of BPA.3.Detection of five estrogens in mask by SPE using P_Gr-MMA as adsorbent materials combined with HPLCCombined with HPLC method,SPE based on P_Gr-MMA sorbent was used to analyze five estrogens,including estradiol,ethinylestradiol,estrone,diethylstilbestrol and dienestrol in facial mask.Under optimized SPE conditions,the melthod was applied to the anlysis of standard addition of 5 estrogens in facial mask sample,and with optimized extraction condition,i.e.The recoveries of estradiol,ethinylestradiol,estrone,diethylstilbestrol and dienestrol were 104.26%¹11.63%,100.35%¹08.39%,84.27%¹15.83%,79.62%⁹8.34%,77.53%⁹4.35%,respectively,RSD%was less than 7.6%（n=3）.In comparison with several related materials(P_GO-MMA,P_MMAMA and commercialized product C₁₈8 silica gel),P_Gr-MMAr-MMA materials as SPE adsorbent exhibited the best extraction efficiency for five estrogens,meanwhile,P_MMA can’t enrich 5 estrogens completely,and P_Gr-MMA and P_GO-MMA were better than C₁₈.The experimental results indicated that graphene could effectively enhanced adsorption capacity.Therefore,the proposed method was suitable for the determination of estrogens in cosmetics.This paper provided a novel graphene composites as adsorbent material for SPE,which graphene was dispersed uniformly in the organic polymer with good stability.This material was effectively applied to SPE of phenolic estrogens.It is also desirable to extend to extraction of other compounds and systems.