高效氯氟氰菊酯水乳剂在小白菜和土壤中的残留动态研究

Residue Dynamics of Cyhalothrin in Cabbage and Soil

采用田间试验的方法,研究了高效氯氟氰菊酯在小白菜及土壤中的残留动态,应用气相色谱法测定了高效氯氟氰菊酯在小白菜和土壤中的残留量。该方法小白菜中高效氯氟氰菊酯的平均回收率分别为91.03%～94.39%;土壤中高效氯氟氰菊酯的平均回收率分别为88.72%～91.70%。结果表明,高效氯氟氰菊酯在小白菜和土壤中消解较快,其半衰期分别为5.53～7.37天和3.09～7.15天。在小白菜上使用25g/L高效氯氟氰菊酯乳油,按照推荐使用剂量(有效成分7.5g/hm2)最多施药3次,最后1次施药7天后,采收的小白菜中高效氯氟氰菊酯残留量小于0.2mg/kg。

A field experiment was conducted to reveal residue dynamics and residues of cyhalothrin in cabbage and soil distributed in Changsha,Yangzhou,Hangzhou and Hangzhou. The residues of cyhalothrin in cabbage and soil were determined by gas chromatography with ECD detector. The average recoveries of cyhalothrin were in a range of 91.03%-94.39% in cabbage and 88.72%-91.70% in soil. The results showed that the degradation of cyhalothrin in cabbage and soil was in accord with the regression equation. The half-life of cyhalothrin were 5.53-7.37 d and 3.09 d7.15 d in cabbage and in soil,respectively. When the cabbage was sprayed three times with 7.5 g/hm2 cyhalothrin 25 g/L E.C,and the last application was done 7 days before harvesting,the final residues of cyhalothrin in cabbage was lower than 0.2 mg/kg,demonstrating that it was safe to apply cyhalothrin to cabbage.