烯啶虫胺在柑橘和土壤中的残留及消解动态

Residue decline study of nitenpyram in orange and soil

应用超高效液相色谱-串联质谱(UPLC-MS/MS)建立了烯啶虫胺在柑橘和土壤中的残留分析方法,并采用该方法研究了烯啶虫胺在田间柑橘和土壤中的消解动态。样品分别采用乙腈和甲醇提取,UPLC-MS/MS检测,外标法定量。在0.1～5 mg/L质量浓度范围内,烯啶虫胺的仪器响应值与质量浓度呈良好线性关系,相关系数均在0.99以上。该方法的最小检出量为1.0×10-11g,在柑橘和土壤中的最低检测浓度均为0.05 mg/kg。当添加水平为0.05～2 mg/kg时,回收率在70.8%～104.1%之间,相对标准偏差在4.7%～12.3%之间。消解动态试验结果表明,烯啶虫胺在柑橘和土壤中消解的半衰期分别为3.4～10.7 d和1.8～5.4 d,表明烯啶虫胺属于易降解农药(t1/2<30 d)。

A rapid,accurate and sensitive method has been developed to determine nitenpyram residues in orange and soil samples by UPLC-MS/MS.The degradation dynamics of nitenpyram residues in orange and soil were studied under condition of field trials.The samples were extracted by acetonitrile or methanol,and detected by UPLC-MS/MS.External reference method was used for quantitative determination.The linearity was satisfied（r〉0.99） in the concentration range of 0.1-5 mg/L.The limit of detection was 1.0×10^-11 g,and the limit of quantification in orange and soil was 0.05 mg/kg.The average fortified recoveries varied from 70.8% to 104.1% and relative standard deviation varied from 4.7% to 12.3% when nitenpyram was spiked at 0.05-2 mg/kg level in various matrixes.The study of residue dynamics indicated that the decline curve accorded with the first-order kinetics equation,and the half-life of nitenpyram in orange and soil were 3.4-10.7 d and 1.8-5.4 d,respectively.