Residue and decline dynamics of cytosinpeptidemycin in tobacco and soil

The field trial and sample analysis of cytosinpeptidemycin in tobacco leaf and soil were assessed.The sample of fresh tobacco leaf,cured tobacco leaf or soil was extracted with mixture of acetonitrile-water (19:1 or 17:3,V:V) and filtrated with PEP-SPE,and then determined with the high performance liquid chromatography (HPLC) equipped an ultraviolet (UV) detector.The limit of detection (LOD) of this method was 0.05 mg/kg.The average additive recoveries fortified at 0.05-2 mg/kg levels were 82.7%-89.6% in fresh tobacco leaf,and 78.7%-81.5% in cured tobacco leaves,and 79.6% -97.8% in soil.The half-lives of cytosinpeptidemycin in tobacco leaf ranged 3.4-5.1 d,and 1.3-3.1 d in soil,respectively.The results showed that the ultimate residue of cytosinpeptidemycin in cured tobacco leaves and soil sampled in different interval were below LOD,when 2% cytosinpeptidemycin AS was applied with the label recommended dose.