己唑醇在梨和土壤中残留量的气相色谱分析方法

建立了气相色谱仪测定梨果和土壤中己唑醇的残留分析方法,并开展了市售梨果样品中己唑醇残留量的检测。梨果和土壤样品以乙腈为提取溶剂提取,用中性氧化铝和弗罗里硅土的混合柱净化,经浓缩后正己烷定容,GC-ECD测定己唑醇残留量。在添加浓度范围内(0.01~0.5 mg·kg~(-1)),梨果中己唑醇的平均添加回收率为77.4%~99.1%,相对标准偏差为7.5%~9.8%;土壤中己唑醇的平均添加回收率为82.2%~95.3%,相对标准偏差为5.8%~9.9%。该方法的准确性、精确性均达到农药残留分析的要求。采用该方法对市售梨果实际样品的检测结果表明,梨果中己唑醇的残留量均未超过最高残留限量值。

Analytic method of hexaconazole residue in pear and soil

The analytic method for detecting hexaconazole residue in the pear fruit and soil was studied. The residues of prochaloraz in the pear fruit randomly collected from markets were determined. The residues in pears or soils were extracted with acetonitrile by mechanical oscillating and ultrasonic oscillation, cleaned up with mixed sorbents of Florisol and alumina in column chromatography, and detected with GC-ECD. Four concentrations of hexaconazole of 0.01, 0.05, 0.1 and 0.5 mg/kg were spiked in the pear fruit, respectively. The recoveries of hexaconazole in pears ranged from 77.4% to 99.1%, and in soils ranged from 82.2% to 95.3%; the CV ranged in pears between 7.5% and 9.8%, and in soils between 5.8% and 9.9%, correspondingly. The results showed that the accuracy of the method met the standard of pesticide residue analysis. Test results of pear fruits collected from markets showed that the residues in pears were under the maximun residue limit of hexaconazole in pear.