气相色谱法测定铁皮石斛、浙贝母和人参中嘧菌酯残留

本文建立了铁皮石斛、浙贝母和人参三种中药材中嘧菌酯的残留检测方法。样品采用乙腈提取,二氯甲烷液-液萃取,弗罗里硅土-中性氧化铝-活性炭柱层析净化,乙酸乙酯定容,气相色谱-电子捕获检测器(GC-ECD)检测,基质外标法定量。结果表明:在0.01~1.0mg/L范围内,不同基质中嘧菌酯的峰面积与其质量浓度间呈良好线性关系,相关系数均大于0.999;在0.01、0.1和0.5mg/kg的添加水平下,嘧菌酯在3种中药材基质中的平均回收率为85.0%~94.9%,日内相对标准偏差(RSD)均小于5.2%(n=5),日间RSD均小于6.7%(n=15);其在铁皮石斛、浙贝母和人参基质中的检出限(LOD)为0.002~0.004mg/kg,定量限(LOQ)均为0.01mg/kg。方法的准确度和精密度均满足残留分析要求,适用于铁皮石斛、浙贝母和人参中嘧菌酯的检测。

Determination of Azoxystrobin Residues in Dendrobium officinale,Fritiliariae thunbergii and Panax ginseng by Gas Chromatography

A method for determination of azoxystrobin residues in Dendrobium officinale,Fritiliariae thunbergii and Panax ginseng was established.Samples were extracted ultrasonically with acetonitrile,partioned by dichloromethane,and then cleaned up by column chromatography (florisil-neutral aluminaactivated charcoal).The sample extracts were determined by GC-ECD with matrix-matched external standard method.The results indicated that the matrix-matched calibration curves showed good linearity in the concentration range of 0.01-1 mg/L with correlation coefficients higher than 0.999.The average recoveries of azoxystrobin in the three matrices were between 85.0％ and 94.9％ at the spiked levels of 0.01,0.1 and 0.5 mg/kg,with intra-day relative standard deviations lower than 5.2％(n=5) and interday relative standard deviations lower than 6.7％ (n=15).The limits of detection (LOD) in Dendrobium officinale,Fritiliariae thunbergii and Panax ginseng were 0.002-0.004 mg/kg,the limits of quantification (LOQ) were 0.01 mg/kg.The method was easy,efficient,sensitive and accurate,which can be suitable for determination of azoxystrobin residues.