气相色谱法测定淡水养殖环境中的4种拟除虫菊酯类农药残留

Determination of Four Pyrethroid Residues in Fresh Aquacultural Environment by Gas Chromatography

建立了气相色谱法测定淡水养殖水体、鱼、水生植物及沉积物中甲氰菊酯、氯氰菊酯、氰戊菊酯及溴氰菊酯4种拟除虫菊酯类农药残留。样品分别以正己烷、丙酮-石油醚(体积比为1∶3)、乙腈超声提取,经稀H2SO4、自制碳粉及中性氧化铝柱以及浓H2SO4净化后,以DB-5MS色谱柱(30m×0.25mm,0.25μm)分离,电子捕获检测器(ECD)检测,外标法定量。结果表明,4种拟除虫菊酯在1.0~100μg/L范围内线性关系良好(R2≥0.998),在水体、鱼、水生植物及沉积物中3个添加水平的平均加标回收率分别为81.1%~112.4%、62.3%~98.1%、78.3%~99.3%、69.8%~120.9%,相对标准偏差在2.65%~8.45%之间,检出限范围为0.005~1μg/kg。该方法简便、快捷,回收率高,稳定性好,溶剂用量较少,能满足淡水养殖环境中拟除虫菊酯类农药残留的检测要求。

A method for the determination of four pyrethroid residues in water,fishes,hydrophytes and sediments by gas chromatography was established.The samples were extracted with n-hexane,acetonepetroleum ether（1∶3,V/V）and acetonitrile,then the solutions were purified by sulfuric acid,homemade carbon powder and neutral alumina column,separated by DB-5 MS column（30 m×0.25 mm,0.25μm）,detected by GC-ECD,and quantified by external standard method.The results showed that the linearity of pyrethroids was good in the range of 1.0-100μg/L（R^2≥0.998）.At three spiked levels,the average recoveries of the four kinds of pyrethroids in water,fishes,aquatic plants and sediments were 81.1%-112.4%,62.3%-98.1%,78.3%-99.3% and 69.8%-120.9%,respectively with the relative standard deviations of 2.65%-8.45% and the detection limits of 0.005 and 1μg/kg.The methods were simple,rapid with high recovery rate and good stability,which can meet the requirements of pyrethroid residue detection and provide the method support for the relevant detection.