二氯吡啶酸·氨氯吡啶酸·烯草酮及其代谢产物在油菜籽与土壤中的残留分析方法

Residual Analysis of Clopyralid·Picloram·Clethodim and Its Metabolites in Rapeseed and Soil

[目的]建立一种同时测定油菜籽和土壤中二氯吡啶酸、氨氯吡啶酸、烯草酮及其代谢物烯草酮砜和烯草酮亚砜的高效液相色谱串联质谱法。[方法]油菜籽和土壤中的二氯吡啶酸、氨氯吡啶酸、烯草酮及其代谢物烯草酮砜和烯草酮亚砜用乙腈提取,采用QuEChERS法净化,用Agilent Zorbax RRHD Eclipse Plus C_(18)色谱柱分离,流动相为甲醇-水(0.1%甲酸和5 mmol/L乙酸铵),采用多反应监测模式(MRM),外标法定量。[结果]对样品中的二氯吡啶酸、氨氯吡啶酸、烯草酮、烯草酮砜和烯草酮亚砜进行不同水平的添加回收试验,方法的回收率为70.4%~108.6%,相对标准偏差为0.5%~14.8%。最低检测质量浓度为0.05 mg/L。在上述检测条件下,二氯吡啶酸、氨氯吡啶酸、烯草酮、烯草酮砜、烯草酮亚砜的最小检出量分别为0.08、0.1、0.008、0.004、0.007 ng。[结论]该方法的灵敏度、准确度、精密度符合农药残留分析的要求,适合大批量的油菜样品的检测。

[Aims] A new method for analysis of clopyralid, picloram, clethodim and the metabolites residues in rapeseed and soil by high performance liquid chromatography-tandem mass spectrum was developed. [Methods] The clopyralid, picloram, clethodim and the metabolites clethodim sulfone and clethodim sulfoxide residues in rapeseed and soil were extracted with acetonitrile and purified by QuEChERS method. Then Agilent Zorbax RRHD Eclipse Plus C^s chromatographic column was used to separate the residues, the mixture of 0.1% formic acid and 5 mmol/L ammonium acetate aqueous solution and methanol was used as mobile phase in gradient elution. Finally, the samples were detected under multiple reaction mode （MRM）. The matrix-matched external standard calibration curves were used for the quantitative analysis. [Results] The average recoveries ranged from 70.4 to 108.6%, the relative standard deviations were 0.5-14.8%. The lowest detectable concentrations for clopyralid, picloram, clethodim and the metabolites clethodirn sulfone and clethodim sulfoxide in samples were 0.05 mg/L. Under these conditions, the limits of detection for clopyralid, picloram, clethodim, elethodim sulfone and clethodim sulfoxide were 0.08, 0.1, 0.008, 0.004, 0.007 ng, respectively. [Conclusions] The method is simple, reliable, and met with the requirement for pesticide residue analysis, which can be applied for determining clopyralid, picloram, clethodim and the metabolites residues in rape samples.