氟唑磺隆、甲基二磺隆、炔草酯和炔草酸在小麦中的残留分析

Residue analysis of flucarbazone-sodium, mesosulfuron-methyl,clodinafop-propargyl and clodinafop in wheat

以QuEChERS前处理方法为基础,采用高效液相色谱-串联质谱(HPLC-MS/MS)检测技术,建立了除草剂氟唑磺隆、甲基二磺隆、炔草酯及其代谢物炔草酸4种化合物在小麦中残留的分析方法。麦粒样品中加入5 mL体积分数为0.1%的甲酸水溶液后,以10 mL乙腈提取,用50 mg C_(18)与100 mg无水硫酸镁净化;麦秆样品中加入10 mL体积分数为2%的甲酸水溶液后,以10 mL乙腈提取,用100 mg C_(18)与200 mg无水硫酸镁净化。结果表明:氟唑磺隆在0.005、0.01和0.1 mg/kg,甲基二磺隆在0.01、0.02和0.1 mg/kg,炔草酯和炔草酸在0.05、0.1和0.5 mg/kg添加水平下,4种化合物在麦粒中的回收率在76%～97%之间,在麦秆中的回收率在83%～102%之间,相对标准偏差均小于10%,r> 0.99。4种化合物在麦粒和麦秆中的定量限分别为:氟唑磺隆0.005 mg/kg,甲基二磺隆0.01 mg/kg,炔草酯和炔草酸均为0.05 mg/kg。该方法可满足小麦样品中4种化合物的残留分析要求。

A modified QuEChERS method was developed and validated for the determination of flucarbazone-sodium,mesosulfuron-methyl,clodinafop-propargyl and clodinafop in wheat kernel and straw by high-performance liquid chromatography coupled with tandem mass spectrometry(HPLCMS/MS).The wheat kernel was extracted with 10 mL acetonitrile,after 5 mL 0.1%formic acid solution was added to improve the extraction efficiency.Samples were cleaned up by 50 mg C18 and 100 mg anhydrous MgSO4.After adding 10 mL 2%formic acid solution,the wheat straw was extracted with 10 mL acetonitrile.100 mg C18 and 200 mg anhydrous MgSO4 were used to clean up the samples.The average recoveries of four compounds in wheat kernel and wheat straw were 76%-97%and 83%-102%,respectively,with the relative standard deviations(RSDs)for those four compounds less than 10%.Good linearity was achieved with determination coefficients higher than 0.99.The limit of quantity(LOQ)is 0.005 mg/kg for flucarbazone-sodium,0.01 mg/kg for mesosulfuron-methyl,0.05 mg/kg for clodinafop-propargyl and clodinafop.This method meets the requirements of pesticide residue analysis.