超高效液相色谱-串联质谱法测定茶叶中6种农药残留

Determination of 6 pesticide residues in tea by ultra performance liquid chromatography-tandem mass spectrometry

中文关键词:  超高效液相色谱-串联质谱  茶叶  农药残留

英文关键词:ultra performance liquid chromatography-tandem mass spectrometry  tea  pesticide residues

中文摘要:

      目的 建立超高效液相色谱-串联质谱法测定茶叶中吡虫啉、多菌灵、啶虫脒、水胺硫磷、三唑磷和甲基异柳磷6种农药残留的方法。方法 样品经乙腈提取, NH2固相萃取小柱富集、净化, 以二氯甲烷-甲醇(9:1, V:V)为洗脱溶液; 样品经浓缩定容后, 采用Thermo C18(2.1 mm×50 mm, 1.7 μm)色谱柱分离, 流速为0.3 mL/min, 以水-甲醇-乙腈为流动相进行梯度洗脱, 采用超高效液相色谱-串联质谱法多反应监测模式进行测定, 采用基质标准溶液外标法定量。结果 6种农药在0.005~0.25 μg/mL浓度范围内呈良好的线性关系, 相关系数为0.9973~0.9998。当添加水平为0.005、0.025、0.25 mg/kg时, 6种农药在茶叶中的加标回收率为72.4%~106.6%, 相对标准偏差为1.6%~10.0%。方法定量限为0.5~5 μg/kg。结论 该方法操作简单、快速, 可适用于茶叶中吡虫啉、啶虫脒、多菌灵、水胺硫磷、三唑磷和甲基异柳磷6种农药残留的测定。

英文摘要:

      Objective To develop a method for the determination of 6 kinds of pesticide residues (imidacloprid, carbendazim, acetamiprid, isocarbophos, triazophos and isofenphos-methyl) in tea by ultra performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS). Methods The samples were extracted with acetonitrile, then concentrated and cleaned up by NH2 solid phase extraction (SPE) using dichloromethane-methanol (9:1, V/V) as elution solution. Samples were prepared after concentration and constant volume, and separated by Thermo C18 (2.1 mm×50 mm, 1.7 μm) column using water-methanol-acetonitrile as mobile phase for the gradient elution at the flow rate of 0.3 mL/min. The target compounds were determined by UPLC-MS/MS under multi reaction monitoring (MRM) mode, and then quantitatively analyzed by external standard method using the matrix-matched standard solution. Results Six kinds of pesticides had good linear relationships between peak areas and concentrations in the range of 0.005~0.25 μg/mL, and the correlation coefficients were 0.9973~0.9998. The spiked recoveries of 6 kinds of pesticides in tea were ranged from 72.4% to 106.6% at the spiked levels of 0.005, 0.025 and 0.25 mg/kg, with relative standard deviations of 1.6%~10.0%. The limits of quantification were 0.5~5 μg/kg. Conclusion This method is rapid and simple, and can be applied for the determination of 6 kinds of pesticide (imidacloprid, carbendazim, acetamiprid, isocarbophos, triazophos and isofenphos-methyl) residues in tea.