QuEChERS-高效液相色谱-串联质谱法测定黄瓜和土壤中甲基硫菌灵和多菌灵

Determination of thiophanate-methyl and carbendazim in cucumber and soil by QuEChERS-high performance liquid chromatography-triple quadrupole tandem mass spectrometry

建立了黄瓜和土壤样品中甲基硫菌灵和多菌灵的QuEChERS-高效液相色谱-电喷雾串联质谱(HPLC-ESI-MS/MS)检测方法。样品用乙腈溶液提取,经QuEChERS方法净化,以Agilent ZORBAX SB-C18色谱柱(30 mm×2.1 mm,5μm)进行HPLC分离,以电喷雾电离串联质谱正离子多反应监测(MRM)模式进行测定。对甲基硫菌灵和多菌灵在黄瓜和土壤中4个添加水平(0.01、0.05、0.1和1.0 mg/kg)下的回收率进行了测定,甲基硫菌灵在黄瓜中的添加回收率为87.3%～96.0%(相对标准偏差(RSD)为8.0%～9.3%),在土壤中的添加回收率为88.8%～93.4%(RSD为5.3%～9.9%);多菌灵在黄瓜中的添加回收率为87.1%～92.3%(RSD为5.2%～7.5%),在土壤中的添加回收率为85.8%～90.9%(RSD为5.3%～13.2%)。该方法样品前处理简单、快速,分析时间短,灵敏度、准确度和精密度均符合农药残留检测要求,适用于黄瓜和土壤中甲基硫菌灵和多菌灵残留的检测。

A method was developed for the determination of thiophanate-methyl and carbenda- zim residues in cucumber and soil by using QuEChERS-high performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry （HPLC-ESI-MS/MS）. The resi- dues in the samples were extracted by acetonitrile, cleaned up by developed QuEChERS method. and then analyzed by using LC-MS/MS in multiple reaction monitoring （MRM） mode via positive electrospray ionization with an Agilent ZORBAX SB-C18 column （ 30 mm×2. 1 ram, 5μm） as the analytical column. The recoveries of thiophanate-methyl spiked at four levels of 0.01, 0.05, 0. 1 and 1.0 mg/kg were from 87.3% to 96.0% with the relative standard deviations （RSDs） of 8.0%-9.3% in cucumber, from 88.8% to 93.4% with the RSDs of 5.3%- 9.9% in soil; the recoveries of carbendazim spiked at the same levels as those of thiophanate- methyl were from 87. 1% to 92.3% with the RSDs of 5.2% - 7.5% in cucumber, from 85.8% to 90.9% with the RSDs of 5.3% -13.2% in soil. The method is simple, rapid and characterized with acceptable sensitivity and accuracy to meet the requirements of the pesticide residue anal- ysis. This method is applicable to confirm the residues of thiophanate-methyl and carbendazimin cucumber and soil.