材料期刊网

制备了苯乙烯（St）和甲基丙烯酸（MAA）共聚物改性的磁性微球 Fe3O4@P（St-co-MAA），并将其作为磁固相萃取吸附剂，建立了磁固相萃取（MSPE）-气相色谱（GC）-火焰光度检测（FPD）联用分析有机磷农药（OPPs）残留的新方法。以5种有机磷农药（二嗪农、甲基毒死蜱、杀螟硫磷、毒死蜱和喹硫磷）为目标分析物，考察并优化了吸附和解吸条件，确定了最佳实验条件。在最优的实验条件下，方法对5种 OPPs 的检出限（ S/N＝3）为0.013~0.305μg/L，方法的相对标准偏差（ RSD，n＝7）为3.1％~8.8％，富集倍数为406~951，线性范围达3个数量级。将该方法应用于新鲜番茄汁、草莓汁样品中的 OPPs 残留分析，加标回收率为85.4％~118.9％。该方法具有检出限低、分析速度快、富集倍数高等优点，为有机磷农药的残留分析提供了新的技术平台。

A novel method for the determination of organophosphorous pesticides( OPPs)in fresh juice samples was developed. Fe3O4@ P( St-co-MAA)magnetic microparticles were syn-thesized and modified with styrene( St)and methacrylic acid( MAA)by coating St and MAA on magnetic particles and characterized by a series of techniques. The results indicated that Fe3O4 magnetic nanoparticles(MNPs)have been successfully modified with St and MAA. Based on the prepared Fe3O4@ P( St-co-MAA)magnetic microparticles,a novel method of magnetic solid phase extraction( MSPE)-gas chromatography( GC)-flame photometric detection( FPD) was developed for the determination of OPPs. The extraction/desorption conditions of MSPE were optimized,and the analytical performance was evaluated under the optimal conditions. The limits of detection( LODs,S/N=3)for target OPPs were in the range of 0. 013-0. 305 μg/L with the RSDs(n=7)ranging from 3. 1% to 8. 8%. The enrichment factors varied from 406 to 951. The linear ranges were over three orders of magnitudes( R2﹥0. 99)and the reproducibil-ities were 7. 4%-14. 5%( n=5). Finally,the proposed MSPE-GC-FPD method was successfully applied to the analysis of the five OPPs in fresh tomato and strawberry juice samples,with the recoveries of target OPPs in the range of 85. 4%-118. 9% for the spiked samples. The proposed MSPE-GC-FPD method is featured with low cost,fast separation and high enrichment factor.