稻米中13种苯氧羧酸类除草剂多残留的高效液相色谱-质谱测定

Simultaneous Determination of Phenoxyacid Herbicides in Rice by High Performance Liquid Chromatography-Mass Spectrometry

建立了高效液相色谱-质谱联用（HPLC—MS）选择离子监测（SIM）同时测定稻米中13种苯氧羧酸类除草剂多残留的方法。样品经过乙腈提取，盐酸酸化，SCX阳离子交换吸附剂分散固相萃取净化后，采用HPLC—MS测定。对13种苯氧羧酸类除草剂的液相色谱分离、样品前处理条件进行了详细的研究和优化，13种苯氧羧酸类除草剂在0．02～1．0mg／L范围内线性良好，相关系数为0．9954～0．9998。在0．05～1．0mg／kg范围内，平均添加回收率为77％～99％，相对标准偏差为0．9％～14．9％。

A high performance liquid chromatography -mass spectrometric method has been developed for simultaneous determination of 13 phenoxyaeid herbicides in rice. Phenoxyaeid herbicides was extracted with acetonitrile -water, acidified with HCl, then cleaned up with SCX dispersive solid phase extraction, and finally analyzed by high performance liquid chromatography （HPLC） -mass spectrometry （MS）. Sample preparation and HPLC - MS analytical conditions were critically examined and optimized in this paper. The method showed good linearity over the range of 0. 02 - 1.0 mg/L for 13 phenoxy-acid herbicides with correlation coefficients of 0. 995 4 -0. 999 8. The average recoveries of 13 phenoxy acid herbicides in spiked rice ranged from 77% to 99% , and the relative standard deviations were between 0.9% and 14. 9% .