中药中有机磷农药残留量的毛细管气相色谱测定方法

Determination of Organophosphorous Pesticide Residues in Medicinal Plants and Traditional Chinese Preparations by Capillary Gas Chromatography

建立了同时测定中药中8种有机磷农药残留量的前处理及其毛细管气相色谱测定法 ,选用氮磷检测器和SPB -1701毛细管柱,以丙酮 -石油醚混合溶剂提取残留农药。结果表明 :敌百虫、敌敌畏、甲胺磷、二嗪农、乐果、马拉硫磷、甲基对硫磷和对硫磷8种农药在25min内有良好的分离 ;3个不同浓度的标准添加 ,其回收率范围为74.96 %～116.8 % ,相对标准偏差范围为0.71 %～16.91 % ;检出限范围为1.1×10-2～3.36×10-1 pg。该法具有灵敏度高、选择性强、操作简便、重现性好、适用性广等特点 ,有着良好的应用前景。

An analytical method is described for the quantitative determination of residues of 8 organophosphorous pesticides in medicinal plants and traditional Chinese preparations: trichlorfon, dichlorvos, methamidophos, diazinon, dimethoate, malathion, methyl _ parathion and parathion. The pesticides in samples were extracted with acetone-petroleum ether (volume ratio 1∶1, 50 mL, 2 times), and the concentrated extract was determined directly. The residues were determined by capillary gas chromatography with nitrogen-phosphorous detector and a SPB-1701 column (30 m×0.32 mm× 0.25 μm). All those 8 pesticides were well separated in 25 min. The range of recovery and RSD of the pesticides spiked with 3 levels are 74.96%～116.8% and 0.71%～16.91%, respectively. The range of detection limits is 1.1×10-2～3.36×10-1 pg. This method is sensitive, selective, repeatable, and easy in operation.