吡虫啉在金银花中的残留动态研究

Study on residue trend of imidacloprid in Flos Lonicerae Japonicae

目的:采用高效液相色谱法研究吡虫啉在金银花中的残留动态。方法:样品经甲醇提取,二氯甲烷萃取,层析柱净化,采用十八烷基键合硅胶柱,流动相为乙腈-0.1%磷酸梯度洗脱,流速为1mL·min^(-1);检测波长270 nm。结果:样品的加样回收率为87.53%～98.50%,RSD 为1.8%～2.7%。试验结果表明,吡虫啉在金银花中的半衰期为1.58 d,施药10 d 后残留量由4.3025 mg·kg^(-1)降至0.0482 mg·kg^(-1),最终残留量在0.002 mg·kg^(-1)以下。结论:在正常喷药浓度的加倍剂量2000倍条件下,安全采收间隔期为10 d 以上。

Objective：To study on residue trend of imidacloprid in Flos Lonicerae Japonicae. Method：It was carried out by HPLC. Imidacloprid was extracted with methanol, dichloromethane, cleaned up with chromatography column,then separated on Spherisorb C18 column with acetonitrile -0.1% phosphoric acid as mobile phase, the flow rate was 1mL·min^-1, detected at 270 nm. Results： The fortified average recoveries varied from 87.53% - 98.50% ,and RSD was among 1.8% -2.7%. The half- life of imidacloprid in Flos Lonicerae Japonicae was 1.58 d,the residue amount of imidacloprid was from 4.3025 mg·kg^-1 to 0.0482 mg·kg^-1 after 10 d,the final residue amount was less than 0.002 mg·kg^-1. Conclusion：When normal concentration doubled was applied, that was diluted with 2000 times of water,the safe interval period was more than 10d.