气相色谱-电子捕获检测器法测定柑桔和土壤中苯丁锡的残留

建立了采用气相色谱-电子捕获检测器(GC-ECD)测定柑桔和土壤中苯丁锡残留量的分析方法。样品经乙腈提取,浓盐酸衍生化,中性氧化铝柱净化。结果表明:在0.5~5.0 mg/kg添加水平范围内,苯丁锡的平均添加回收率为92% ~98%,相对标准偏差(RSD)为5.8% ~8.7%(n=5)。方法的最小检出量(MDL)为1×10-10g,苯丁锡在桔肉、桔皮、全果和土壤4种基质中的定量限(LOQ)均为0.5 mg/kg。该方法杂质干扰少,准确性及灵敏度满足农药残留检测要求,对检测硬件要求低,适用于柑桔和土壤中苯丁锡残留的分析。消解动态试验结果表明,苯丁锡在柑桔和土壤中的消解半衰期分别为9~14 d和9~11 d,属易降解农药。

Determination of fenbutatin oxide residue in citrus fruit and soil by gas chromatography with electron capture detector

A method for determination of fenbutatin oxide residue in citrus fruit and soil was established based on gas chromatograph with electron capture detector (GC-ECD).Residues were extracted from samples with acetonitrile,followed by clean-up using neutral alumina column and determination using GC-ECD.Average fortified recoveries in samples were found at the range of 92%-98% at fortified levels from 0.5 mg/kg to 5.0 mg/kg,with relative standard deviations of 5.8%-8.7% (n=5).The method detection limit (MDL) of fenbutatin oxide was 1×10^-10g,and the limit of quantification (LOQ) of fenbutatin oxide in samples was 0.5 mg/kg.No interferences were found by using this method for blank samples.The current method need no special instrument and can meet the requirements of pesticide residue analysis on accuracy,sensitivity and precision.In conclusion,this method is suitable for the analysis of fenbutatin oxide residue in citrus fruit and soil.The study indicated that the half-life of fenbutatin oxide in citrus fruit and soil was 9-14 days and 9-11 days.Fenbutatin oxide belongs to the easily degradable pesticide in citrus fruit and soil.