虫螨腈在中药材金银花上的残留检测方法与消解动态研究

目的建立一种金银花中虫螨腈的气相色谱分析方法,并运用该方法对田间消解动态实验采得的金银花样品进行测定,从而为金银花实际生产中虫螨腈的使用提供理论参考。方法金银花样品经丙酮涡旋提取,中性氧化铝层析柱净化后采用Agilent 6890N气相色谱仪(配电子捕获检测器)进行测定,外标法定量。结果在0.02⁰.5 mg·kg^-1的添加水平范围内,虫螨腈在金银花中的平均回收率为83.9%⁹7.6%,相对标准偏差(RSD)为0.6%⁹.2%,最低检测浓度为7.3μg·kg^-1;虫螨腈在金银花上的消解符合一级动力学方程消解半衰期为2.3 d。结论该检测方法经济节约,简便快捷准确度、精密度高,可满足虫螨腈在金银花中的残留分析要求;虫螨腈在金银花上消解速度快属于易降解农药。

Detection Method and Degradation Dynamics of Chlorfenapyr in Honeysuckle Under Field Conditions

OBJECTIVE To develop a gas chromatography(GC)method for determination of chlorfenapyr in flower buds of Lonicera japonica Thunb,and study the degradation dynamics of chlorfenapyr in honeysuckle collected through field experiment,thus providing theoretical references for the application of chlorfenapyr in practical production of honeysuckle.METHODS Honeysuckle samples were extracted with acetone using a vortex mixer and then cleaned up by passing through a neutral alumina chromatography column,followed by detection by gas chromatography with electronic capture detector(GC-ECD).External standard method was used for quantification.RESULTS At fortified levels of 0.02-0.5 mg·kg^-1,the average recoveries of chlorfenapyr in honeysuckle were from 83.9%to 97.6%,with RSDs of 0.6%-9.2%.The limit of detection was estimated to be 7.3μg·kg^-1.The degradation dynamics of chlorfenapyr in honeysuckle conformed to first-order dynamic equation.The degradation half-life of chlorfenapyr was 2.3 d.CONCLUSION The method developed in this experiment is simple,rapid,reliable and in line with the requirements of pesticide residue analysis.The degradation rate of chlorfenapyr in honeysuckle is relatively rapid.Chlorfenapyr belongs to pesticides which are liable to degradation.