菌核净在芹菜中的降解规律

Degradation Rule of Dimetachlone in Celery

为了探明菌核净的残留污染风险,在田间试验条件下,采用气相色谱-质谱法研究了菌核净在芹菜中的降解规律。结果表明,菌核净在芹菜中的降解动态符合一级动力学方程,降解半衰期为6.9 d;菌核净在芹菜中的残留量随施药量的增加和收获时间的缩短而增高;40%菌核净WP在芹菜旺盛生长期以低剂量(360 g/hm2)和高剂量(720 g/hm2)施药3次,距最后一次施药14 d后菌核净的残留量均小于0.60 mg/kg。菌核净在芹菜中的降解转化途径是光解(或水解)和脱氯作用。

To explore residual contamination risk of dimetachlone, degradation rule of dimetachlone in celery leaf were investigated under field condition using gas chromatography-mass spectrometry （GC-MS）. The results showed that degradation of dimetachlone in celery fitted to the first-order kinetics, and the half-life was 6.9 d. Residues of dimetachlone in celery appeared to increase with increasing the application dose and shortening the harvest time. The 40% dimethachlone WP was applied with the dosage of 360, 720 g/hm2 for 3 times in vigorous growth stage of celery, after 14 days application, residues of dimethachlone in celery were less than 0.60 mg/kg. The degradation transformation pathways of dimetachlone in celery were photolysis （or hydrolysis） and dechlorination.