超高效液相色谱法测定吡蚜酮在棉花和土壤中的残留

建立了超高效液相色谱-亲水色谱柱测定吡蚜酮在棉花和土壤中残留量的分析方法。样本在弱碱条件下采用分散固相萃取(QuEChERS)法进行前处理。结果表明:吡蚜酮在棉叶和棉籽中添加水平为0.05~0.50 mg/kg时,其平均回收率分别为76.9%~91.1%和76.4%~93.7%,相对标准偏差(RSD)为7.2%~8.2%和6.2%~9.8%;在土壤中添加水平为0.02~0.5 mg/kg时,平均回收率为83.8%~94.6%,RSD为5.3%~8.0%。在山东和河南两地按推荐剂量(有效成分30 g/hm2)和1.5倍推荐剂量(有效成分45 g/hm2)施用10%吡蚜酮·高效氯氟氰菊酯悬浮剂后4 d,吡蚜酮在土壤和棉叶中的残留量分别低于0.02和0.05 mg/kg;至收获时,其在土壤和棉籽中的最终残留量低于0.02和0.05 mg/kg。

Determination of pymetrozine residues in cotton and soil by ultra-performance liquid chromatography

A method based on QuEChERS sample preparation at weak alkali condition and ultra-performance liquid chromatography detection with hydrophilic chromatographic column was developed for determining pymetrozine residues in cotton and soil. The results indicated that average recoveries for cotton leaf at three levels (0.05, 0.1 and 0.5 mg/kg) ranged from 76.9%-91.1% with relative standard deviations (RSD) of 7.2%-8.2%, for cotton seed ranged from 76.4%-93.7% with RSD of 6.2%-9.8%. Average recoveries for soil at four levels (0.02, 0.05, 0.1 and 0.5 mg/kg) ranged from 83.8%-94.6% with RSD of 5.3%-8.0%. 10% pymetrozine·lambda-cyhalothrin suspending agent was applied in Shandong and Henan according to recommended dose (active ingredient 30 g/ha) and 1.5 times recommended dose (active ingredient 45 g/ha).The pymetrozine residues in soil and cotton leaf were less than 0.02 and 0.05 mg/kg at the 4th day in cotton dissipation experiment under field conditions . At harvest time, the residues of pymetrozine in cottonseed and soil were less than 0.05 and 0.02 mg/kg, respectively.