QuEChERS净化-超高效液相色谱-串联质谱法检测芒果中3种杀菌剂残留

建立了QuEChERS净化-超高效液相色谱-串联质谱(UPLC-MS/MS)同时检测芒果中吡唑醚菌酯、腈苯唑和烯唑醇残留的分析方法。样品经改进的QuEChERS方法萃取净化:使用不含缓冲盐的乙腈萃取,N-丙基-乙二胺(PSA)和C_(18)吸附剂填料分散净化,离心后过滤膜,经UPLC-MS/MS检测。采用ACQUITY UPLC~(TM)BEH C_(18)(2.1 mm×100 mm,1.7μm)色谱柱分离,经流动相为甲醇和乙酸铵水溶液梯度洗脱,电喷雾正离子源(ESI~+)多反应监测(MRM)模式检测,外标法定量。结果表明:在5~500 ng/mL范围内,吡唑醚菌酯、腈苯唑和烯唑醇的质量浓度与相对应的峰面积间呈良好的线性关系,相关系数均大于0.998,检出限(LOD)在0.2~0.6μg/kg之间;在0.50(腈苯唑为1.0)、2.5、5.0和50μg/kg4个添加水平下,平均添加回收率在70%~105%之间,相对标准偏差(RSD)在0.90%~4.6%(n=5)之间。该方法具有简便、快速、准确度高和成本低廉等优点,可用于同时检测芒果中吡唑醚菌酯、腈苯唑和烯唑醇的残留量。

Determination of three fungicides in mango using QuEChERS method and ultra-performance liquid chromatography-tandem mass spectrometry

A multiresidue method was developed for the simultaneous determination of pyraclostrobin, fenbuconazole and diniconazole in mango by using ultra performance liquid chromatography coupled with tandem mass spectrometry(UPLC-MS/MS). The sample preparation using the modified QuEChERS(quick, easy, cheap, effective, rigged, and safe) method completed the extraction and clean up steps. In this buffer-free QuEChERS method, samples were extracted with acetonitrile, cleaned up with primary secondary amine(PSA) and C18 sorbent, then centrifuged and filtrated before detection. The UPLC-MS/MS method was performed on ACQUITY UPLCTM BEH C18(2.1 mm×100 mm, 1.7μm) and the mobile phase were methanol and ammonium acetate aqueous solution. The positive electrospray ionization(ESI+) source under the multiple reaction monitoring(MRM) mode and external standard method were used for detection and quantification. The limits of detection(LOD) for three pesticides ranged from 0.2 to 0.6μg/kg. Calibration curves exhibited good linearity over the concentration range from 5 to 500 ng/mL, with their correlation coefficients above 0.998. At 0.5(fenbuconazole 1.0), 2.5, 5 and 50μg/kg spiked levels, average recoveries for pyraclostrobin, fenbuconazole and diniconazole ranged from 70% to 105%, with relative standard deviations(RSDs) ranged from 0.90% to 4.6%(n=5). The developed method was sensitive, rapid and inexpensive. It was applied for determination of pyraclostrobin, fenbuconazole and diniconazole in mango samples.