三唑酮及其代谢物在烟叶中的降解规律

为制定烟叶中三唑酮及代谢产物的农药残留限量,研究了合理使用条件下,三唑酮及其代谢物三唑醇在烟叶中残留降解规律和残留水平。采用气相色谱电子捕获检测器(GC-ECD)建立了同时测定烟叶中三唑酮和代谢产物三唑醇农药残留的检测方法,结果表明:三唑酮在鲜烟叶和烤后烟叶中的最低检出量(LOQ)分别为 0.01、0.05 mg/kg。三唑酮、三唑醇在鲜烟叶和干烟叶样品中添加水平为 0.01~ 5 mg/kg时,平均添加回收率为 79.8%~97.3%, RSD为 1.5%~9.0%,符合农药残留检测方法要求。对 2011-2012年山东、湖南两地三唑酮残留试验的烟叶样品进行了检测。结果表明,三唑酮在自然生长条件下半衰期为 3.8~5.6d,在储存条件下的半衰期分别为 157~315 d。最终残留试验结果表明,施药剂量和采收安全间隔期与烟叶中农药残留量显著相关,末次施药后 7、14、21 d,烤后烟叶中三唑酮及代谢物的残留量分别为 0.33~6.44 mg/kg、0.15~2.77 mg/kg、0.18~2.53 mg/kg。建议三唑酮及代谢产物在烟叶中 MRL为 5mg/kg,安全间隔期(PHI)为 14 d。 

Degradation of triadimefon and its metabolites residues in tobacco leaves

Degradation of triadimefon and its metabolites triadimenol in tobacco leaves were investigated under GAP conditions. A method for simultaneous determination of triadimefon and its metabolite triadimenol in tobacco was established by method of gas chromatography with electron capture detector(GC-ECD). The limits of quantification(LOQs) of the proposed method were 0.01and 0.05 mg/kg in fresh tobacco leaves and cured tobacco leaves, respectively. The average recoveries of triadimefon and its metabolite triadimenol in fresh tobacco leaves and cured tobacco leaves were in the range of 79.8%~97.3% with relative standard deviation(RSD) of 1.5%~9.0% when spiked at 0.01~5.0 mg/kg. Results showed that half-life of triadimefon under field and storage conditions were 3.8~5.6d and 157~ 315d, respectively. The terminal residues of triadimefon in cured tobacco leaves were 0.33~6.44 mg/kg, 0.15~2.77 mg/kg and 0.18~2.53 mg/kg when collected 7, 14, 21 days after last application. It was recommended that the MRL of triadimefon in tobacco leaves was 5 mg/kg with safety interval(PHI) of 14 days.