【摘要】 建立了土壤中43种农药及代谢物残留的高通量分析方法。土壤样品经乙腈超声萃取后,采用分散固相萃取法进一步对萃取液进行净化。选择修饰N-丙基乙二胺（PSA）的Fe₃O₄磁纳米材料和C₁₈为分散净化吸附剂,采用超高效液相色谱-串联质谱（UPLC-MS/MS）分析。优化实验结果表明,超声萃取时间为10 min、净化吸附剂Fe₃O₄-PSA用量为40 mg、C₁₈用量为30 mg时,农药的回收率最佳。除3-羟基克百威和水胺硫磷（5～250μg/L）外,各农药在2～250μg/L范围内呈良好线性关系,相关系数（R）均大于0.9700,检出限为0.1～1.0μg/L。在10、100和200μg/kg的添加浓度下,目标分析物在土壤中的回收率在74.1%～120.0%之间,相对标准偏差≤18.1%。本方法前处理过程简单,灵敏度高,净化效果好,适用于土壤中多农药残留分析。更多还原

【Abstract】 A simple and rapid sample pretreatment method was developed based on magnetic nanoparticles for multi-pesticides residue analysis in soil samples. The target analytes were extracted by acetonitrile under the assistance of ultra-sonication,followed by the purification of dispersive solid phase extraction. The magnetite（Fe₃O₄） nanoparticles modified with 3- （N,N-diethylamino） propyltrimethoxysilane （Fe₃O₄-PSA） and commercial C₁₈ were selected as the cleanup adsorbents to remove the matrix interferences. The target analytes were further analyzed by ultra-high performance liquid chromatography-tandem mass spectrometry （UHPLCMS/MS）. The factors influencing the recoveries of analytes,such as extraction time,amount of Fe₃O₄-PSA and C₁₈,were optimized. The optimal extraction time was 10 min,and the amount of Fe₃O₄-PSA and C₁₈ were 40 mg and 30 mg,respectively. The method showed good linearity in the concentration range from 2 μg/L to 250 μg/L except for 3-hydroxy-carbofuran and isocarbophos （5 μg/L to 250 μg/L）. The limits of detection（LODs） ranged from 0.1 μg/L to 1.0 μg/L. The recoveries ranged from 74.1% to 120.0% at three spiked concentration levels with relative standard deviations of lower than 18.1%. The proposed method was rapid,simple,low-cost and effective for detection of trace multi-pesticides residue in soil.更多还原