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建立了一种高效、选择性强的分子印迹-基质固相分散萃取结合高效液相色谱测定土壤中4种硫代磷酸酯类农药(毒死蜱、甲基立枯磷、甲基毒死蜱、甲基对硫磷)残留量的方法;并以甲基立枯磷为模板分子,以甲基丙烯酸(MAA)为功能单体,且n(模板分子)∶n(功能单体)=1∶4,以乙二醇二甲基丙烯酸酯(EDMA)为交联剂,以偶氮二异丁腈为引发剂,采用沉淀印迹聚合方法,合成了甲基立枯磷高分子印迹聚合微球(MIPs);以MIPs作为土壤样品提取液的基质固相分散吸附剂,采用HPLC检测处理后的样品,流动相为V(乙睛)∶V(0.1%乙酸水溶液)=3∶1,流速0.8 m L/min,进样量20μL,检测波长210 nm,采用Agilent Eclipse XDB-C8色谱柱(150 mm×4.6 mm,5μm),柱温25℃。结果显示:MIPs对甲基立枯磷有特异性吸附,对其结构相似物毒死蜱、甲基对硫磷和甲基毒死蜱也具有一定的吸附性能;在0.01~5.0 mg/kg范围内,各药剂的质量浓度与相应的峰面积间呈良好的线性关系,相关系数r为0.997 5~0.999 8;4种硫代磷酸酯类有机磷杀虫剂的检出限(LOD)为0.452~1.226μg/kg;添加回收率为76%~96%,相对标准偏差(RSD)为2.8%~7.3%。该方法可用于土壤中硫代磷酸酯类有机磷杀虫剂残留量的测定。
An efficient and selective molecular imprinting-matrix solid-phase dispersion coupled with high performance liquid chromatography (HPLC) was developed for the determination of four thiophosphate pesticides (chlorpyrifos, tolclofos - methyl, chlorpyrifos - methyl, Methionine as a template molecule, methacrylic acid (MAA) as a functional monomer, and n (template molecule): n (functional monomer) = 1: 4 to Ethylene glycol dimethacrylate (EDMA) was used as cross - linking agent, azobisisobutyronitrile was used as initiator, and MIPs were synthesized by precipitation imprinting polymerization. MIPs were used as matrix solid-phase dispersed sorbents for soil samples. The samples were analyzed by HPLC. The mobile phase consisted of V (acetonitrile): V (0.1% acetic acid in water) , Injection volume 20μL, detection wavelength 210 nm, using Agilent Eclipse XDB-C8 column (150 mm × 4.6 mm, 5μm), the column temperature 25 ℃. The results showed that MIPs adsorbed methylprednisolone selectively and had certain adsorption properties to its structural analogues chlorpyrifos, methyl parathion and methyl chlorpyrifos. In the range of 0.01-5.0 mg / kg, The correlation coefficient r was 0.997 5-0.9998. The detection limits (LODs) of the four phosphorothioate organophosphorus insecticides ranged from 0.452 to 1.226 μg / kg. The recoveries were between 76% and 96% with relative standard deviations (RSDs) between 2.8% and 7.3%. The method can be used for the determination of phosphorothioate organophosphorus pesticide residues in soil.