溶剂萃取-气相色谱法测定粮食中硫丹类农药残留量

GC Determination of Residual Endosulfan in Grains with Separation by Accelerated Solvent Extraction

提出了粮食中α-硫丹、β-硫丹、硫丹乙酯、硫丹丙酯和硫丹硫酸盐5种硫丹类有机氯农药的气相色谱测定方法。样品粉碎后以丙酮为溶剂经快速溶剂萃取仪在加热(80℃)状态下静态提取5min、氟罗里硅土固相萃取柱净化后注入毛细管气相色谱仪分离测定。5种硫丹类农药的测定下限(10S/N)分别为0.82～1.75μg.kg-1,平均回收率为88.9%～99.1%,相对标准偏差(n=5)为6.80%～10.23%。

Sample of grain was crushed and extracted with acetone under static condition at 80 ℃for 5 min. The endosulfan pesticides （mainly theα-endosulfan, β-endosulfan, acetate of endosulfan, propyl ester of endosulfan and sulfate of endosulfan） were dissolved in the organic phase and separated from the grain matrix. The extract was evaporated to near dryness by rotary evaporator. The residue was dissolved with petroleum ether and purified by solid phase extraction. The SPE column was rinsed with mixed solvent of petroleum ether and acetone （9＋1）, and the eluate collected was evaporated to near dryness, and the residue was taken up with petroleum ether and used for GC analysis after separation on DB 1701 capillary colunm. The μ-ECD detector was used for the determination. Lower limit of determination （10S/N） for the 5 pesticides were found in the range of 0. 82--1.75 μg·kg-1, and values of RSD＇s （n=5） found were in the range of 6.80%-10. 23%. Values of average recovery found by standard addition method were in the range of 88. 9%-99. 1%.