高效液相色谱-串联质谱法测定蔬菜中杀虫磺的残留量

HPLC-MS/MS Determination of Residual Amount of Bensultap in Vegetables

采用高效液相色谱-串联质谱法测定蔬菜中杀虫磺的残留量。称取样品的匀浆10.00g,用乙腈提取3次(每次20mL),合并提取液并将其蒸缩至约5mL。此溶液通过TPT固相萃取柱净化,保留流出液(主液)。用乙腈-甲苯(3+1)混合液25mL淋洗固相萃取柱,淋出液与主液合并,先在45℃水浴浓缩至约5mL,再于35℃水浴上吹氮蒸干。用甲酸-乙腈(0.1+99.9)混合液溶解残渣并定容至10mL。按所选条件进行高效液相色谱-串联质谱法分析。杀虫磺的质量浓度在1~500μg·L^(-1)内与其对应的峰面积呈线性关系,不同基质中杀虫磺的检出限(3S/N)为0.1~0.4μg·kg^(-1)。以空白样品为基体进行加标回收试验,所得回收率为48.0%~97.7%,测定值的相对标准偏差(n=6)为1.8%~12%。

HPLC-MS/MS was applied to the determination of residual amount of bensultap in vegetables. Homogenized pulp （10. 00 g） of the sample was taken and extracted thrice with CHaCN （20 mL each）. The combined extract was evaporated to about 5 mL. The solution was then purified by passing through TPT SPE column. The eluate （main） was reserved. The SPE column was rinsed with 25 mL of a mixture of CHaCN and toluene （3＋1）. The eluate was combined with the main eluate, and evaporated first to about 5 mL at 45 ℃ in a water bath and then to dryness by N2-blowing at 35℃ in the water bath. The residue was taken up and made up to 10 mL with a mixture of formic acid-CH3CN （0. 1 ＋99. 9）. The solution was then analyzed by HPLC-MS/MS under the condition described. Linear relationship between values of peak area and mass concentration of bensultap was kept in the range of 1- 500 μg · L-1 , with detection limit （3S/N） of bensultap in different matrixes in the range of 0. 1- 0. 4 μg · kg-1. On the base of blank sample, test for recovery was made by standard addition method. Values of recovery found were in the range of 48. 0%--97. 7%, with RSD＇s （n= 6） in the range of 1.80%-12%.