关键词: 豇豆, 茚虫威, 残留, 消解动态, 安全使用技术

Abstract: The residual degradation and safe usage technologies of 15% indoxacarb oil in cowpea were studied by gas chromatography analyzing. The results of determination showed that the LOD of this method was 0.01ng, LOQ was 0.005mg/kg; The average append recovery in cowpea ranged from 84.7%~92.8% and RSD ranged from 3.43%~5.27%. The results of residual degradation dynamics experiments showed that the original sediment of indoxacarb sprayed twice at 7d intervals in cowpea were more than that of once. The residual degradation dynamics of indoxacarb were followed first order kinetic equation. When it was sprayed once, the degradation dynamics equation was C=2.7180·e^-0.2500t, DT₅₀ was 2.8d and T_0.99 was 18.4d. While it was twice, the degradation dynamics equation was C=2.3712·e^-0.2404t, DT₅₀ was 2.9d and T_0.99 was 19.2d. When close to harvest, sprayed once with 48.21 g/hm² of indoxacarb or twice at 7d intervals, the last residues in cowpea were less than 0.2mg/kg 11d after applied, the average residue was 0.103mg/kg and 0.111mg/kg respectively. The quality safety of products fulfils the MRL of Japan.

Key words: Cowpea, indoxacarb, residue, degradation dynamics, safe usage technology