Determination of herbicide ZJ0273 residue in rapeseed by radioisotopic tracing method

Residue of herbicide ZJ0273 (propyl 4-(2-(4,6-dimethoxypyrimidin-2-yloxy)benzylamino)benzoate) in rapeseed under simulated field conditions was evaluated by radioisotopic tracing method. Radio-HPLC and HPLC–MS analysis revealed that the parent ZJ0273 is the only radioactive residue in rapeseed. The residue of propyl 4-(2-(4,6-dimethoxypyrimidin-2-yloxy)[phenyl-U-14C6]benzylamino)benzoate (RCZJ) in postharvest rapeseed from the rape seedlings (Brassica napus L.) in red clayey soil (S1) and in fluvio marine yellow loamy soil (S2) were 0.67 and 1.24 nmol/plant, respectively, based on the 14C radioactivity and the specific activity of the labelled ZJ0273. The RCZJs in the rapeseed (1 kg) from the seedlings in S1 and in S2 were 40.13 and 45.33 nmol, respectively, and the amounts of ZJ0273 in the rapeseed (1 kg) were 16.97 and 19.17 μg. The results suggested that only a trace level of residue of ZJ0273 presents in rapeseed due to the poor root absorption of ZJ0273 and the weak translocation of ZJ0273 from rape leaves.