Determination of Chlorantraniliprole Residues in Corn and Soil by UPLC-ESI-MS/MS and Its Application to a Pharmacokinetic Study

A rapid, highly sensitive, and selective method was developed for the determination of the insecticide chlorantraniliprole (CAP) in corn and soil using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Samples were extracted with acetonitrile, and aliquots were cleaned with solid-phase extraction cartridges. Two precursor-product ion transitions for CAP were measured and evaluated to provide maximum confidence in the results. Average recovery for soil, corn grain, and corn straw at different levels (5 or 10, 40, and 100 mu g kg(-1)) ranged from 74.9 to 97.5%, with intra-day relative standard deviation (RSD) values of 1.9-11.3% and inter-day RSD values of 4.7-10.4%. Coefficients of determination (R (2)) of 0.9988 or higher were achieved for CAP in soil, corn grain, and corn straw matrix calibration curves, from 5 to 1,000 mu g L-1. The CAP limits of quantitation in soil, corn grain, and straw were determined to be 5, 10, and 10 mu g kg(-1), respectively, which were much lower than the maximum residue levels established by the Environmental Protection Agency of United States. UPLC-MS/MS was used to determine the CAP residues in real corn and soil for studies on their dissipation. The trial results showed that the half-lives of CAP changed from 12.6 to 23.1 days in soils and ranged from 4.9 to 5.4 days in corn straws in the districts of Henan and Shandong, and the average levels of CAP residues in corn grains were all < 0.01 mg kg(-1) with a harvest withholding period of 180 days.