气相色谱法测定小麦中的丙草胺残留

研究了丙草胺在小麦粉和植株中残留的分析方法。小麦粉和植株样品中丙草胺经丙酮：乙酸乙酯（体积比1：1）的混合溶剂提取；小麦粉采用超声波提取，植株采用高速匀浆提取；经弗罗里硅土柱层析净化后，气相色谱电子捕获检测器检测。丙草胺的最低检出量为5．0×10^-11g，最低检出浓度在小麦粉中为0．005mg／kg，在小麦植株中为0．01mg／kg，平均回收率在91．1％～95．9％之间，变异系数为2．8％～5．1％，符合残留分析要求。

Determination of Pretilachlor Residue in Wheat by Gas Chromatography

The methods for detecting pretilachlor residue in wheat flour and plants by gas chromatography(GC) were studied.The pretilachlor was extracted with the mixture of acetone and ethyl fluoroacetate at a volume ratio of 1∶1 through ultrasonic wave and high-speed homogenized from wheat flour and wheat plants respectively,and then was purified by Florisil and determined by GC with ECD-detector.The minimum detective limit of pretilachlor was 5.0×10-11 g,and the minimum detective concentration was 0.005 mg/kg and 0.01 mg/kg respectively in wheat flour and plants.The recovery rate of pretilachlor ranged from 91.1% to 95.9% with the variation coefficient between 2.8% and 5.1%.