RESIDUE AND DEGRADATION OF NITENPYRAM IN COTTON AND SOIL

A ultra-high performace liquid chromatograph (UPLC)-MS-MS method for determination of nitenpyram residues in cotton and soil was established. The results showed the average recoveries of nitenpyram were 99.41%—101.54% in cotton leaf,79.42%—94.19% in cotton seed and 96.68%—105.58% in soil with the variation coefficient of 2.88%—5.76%,1.06%—6.30% and 1.40%—4.81%,respectively. A field experiment was conducted to reveal dynamics of nitenpyram residues in cotton and soil. The field experiment results showed that the half life of nitenpyram was 5.75d and 5.58d in cotton leaf and 1.45d and 1.35d in soil in Shandong and Henan. When cotton was sprayed 3—4 times with 10% nitenpyram aqueous solutions of the recommended dose and 1.5 times of the recommended dose,and the last application was done 21d days before harvesting,the final residues of nitenpyram in cotton and soil were all lower than 0.006mg·kg-1. These demonstrate that nitenpyram is a low residual and easily degradable pesticide. So it is safe to apply nitenpyram in cotton with recommended dose.