Dissipation and residues detection of dioctyldiethylenetriamine cetate in rice plant and environment by QuEChERS method and liquid chromatography/electrospray tandem mass spectrometry.

Dioctyldiethylenetriamine acetate (Chinese common name: Xinjunan) is an effective bactericide and virucide widely used on many crops including vegetables and fruits in China. In this study, the dissipation of dioctyldiethylenetriamine acetate 1.8% (w/w) aqueous solution (AS) in rice, soil and water was studied. The result in the supervised field trials showed that the half-lives of dioctyldiethylenetriamine acetate in soil and rice plant were in the range 3.9-6.6 and 6.2-12 days, respectively. It also indicated that the decline followed first-order kinetics. The dissipation of Xinjunan in water, was stimulated in a laboratory container, showed that it could rapidly deposit on solid particles and might form bound residues in surface levels of soil. According to the toxicological data and the dietary intake of rice, a MRL (Maximum Residue Limits) of 0.1 mg/kg for dioctyldiethylenetriamine acetate in the rice was recommended for national accessment. The results indicated that the supervised trials median residues (STMR) is 0.02 mg/kg and only 0.2% of the acceptable daily intake (ADI) is occupied by dietary daily intake in the average Chinese population. It would be unlikely to pose any public health issues if dioctyldiethylenetriamine acetate was applied according to the use pattern suggested by the manufactures on the label.