Preparation Of Porous Polymerized Microspheres And Application In Trace Element Detection

Porous polymeric microspheres(PPMS),a hollow spherical material based on addition polymerization of unsaturated monomers,are formed by random cross-linking and stacking of chains.PPMS was characterized by uniform pore,dense structure and convenient modification,and it can be widely used in drug delivery,separation and catalysis by virtue of highly cross-linked and rich functional groups.In this paper,template formed by precipitation polymerization were used as carriers for shell coating,and removed by solvent etching.Finally,two kinds of microspheres-functionalized were obtained through hydrolysis.And FTIR,N2-adsorption,SEM,TEM were employed for the characterization of prepared PPMS.The diameter of PPMS-1 was 1.4 ?m,and PPMS-2 was 950 nm.The prepared PPMS was filled in solid phase extraction(SPE)as filler for enrichment of elements,and inductively coupled plasma mass spectrometry(ICP-MS)was used in quantification for SPE-ICP-MS method.The factors of SPE such as pH,material amount,extraction flow rate,eluent concentration and volume were optimized through batch experiment.For the column filled with 30 mg of PPMS-1,the optimum extraction was obtained only when the pH was 5.0,extraction flow rate was 2.0 ml min-1,the elution concentration was 0.75 mol L-1,and the elution volume was 2.0 mL.And similarly results were observed when the pH was 6.0,extraction flow rate was 2.5 ml min-1,the elution concentration was 1.0 mol L-1,and the elution volume was 3.0 ml for 30 mg of PPMS-2.The model of adsorption isotherm,kinetic and thermodynamic were used and shows that the adsorption process can be characterized by spontaneous single-layer chemisorption.In optimal conditions,the linearity range of Pb(?)and As(?)was in the range of 0.1-50 ?g L-1,and the detection limits were 6.3 and 9.5 ng L-1 for the method based on PPMS-1.And for PPMS-2,the linearity range of V(V),Cu(?),Cr(?)were 0.05-15 ?g L-1,the detection limits were 2.6,1.3,3.2 ng L-1 respectively,and the linearity range of Cd(?),Pb(II)were 0.05-30 ?g L-1,the detection limits were 1.9 and 0.8 ng L-1.The test of tolerance demonstrated that the material has good property in condition of 500-2000 times interference ions,and 15 cyclic utilization proved the better recyclability of material.The certified reference materials(GBW10052,GBW10043)were used for the verification of accuracy,and shows good similarity between experiment and reference.Besides,practical foods(seaweed,fish,chicken)were used to prove the practicality of the method through the experiment of SPE and returns-ratio,indicated the recovery varies from 84%to 103%.