[Residue degradation dynamics of spinetoram in wolfberry].

ABSTRACT

The safety interval period and residue dynamics of two main components (XDE-175-J and XDE-175-L) of spinetoram in wolfberry were measured. Field experiment design and sampling method were carried out according to the "Guideline on pesticide residue trials". The wolfberry samples were extracted with acetonitrile by ultrasonic, and analyzed by UPLC-MS/MS. The wolfberry was sprayed with 6% spinetoram suspension concentrate (SC) at recommended dosage (1 500 times) and doubling dosage (750 times) (one time) at fructescence of wolfberry. The half-lives of spinetoram residue under recommended dosage treatment was 3.65-4.25 d, and all the fresh and dried fruits conform to first order kinetics equation. The dissipation rate was over 95% in fresh and dried fruits at 14 d after application. In conclusion, spinetoram belongs to the easily degradable pesticide type.