LAUSR

BACKGROUND Recently, chlorfenapyr and diafenthiuron were widely used to prevent and control diseases and pests in tea production. However, rare studies have investigated the dissipation patterns of chlorfenapyr, diafenthiuron, and their metabolites simultaneously in tea matrices. Here, we established an analytical method to investigate the degradation patterns of five target compounds in tea shoots and made tea samples. Moreover, the dietary intake risk assessment of chlorfenapyr-diafenthiuron mixture among Chinese populations was evaluated based on the supervised field experiment. RESULTS The mean recoveries of the primary analytes at five spiking levels were between 95.6%-112.6% in tea shoots and made tea, respectively, and the values of RSD were lower than the 9.7% for all the target analytes. The field trial results showed that the half-lives of chlorfenapyr and diafenthiuron based on the residue definition were 10.0-12.4 days and 4.3-5.9 days in tea shoots. For the dietary intake risk assessment, the risk quotient (RQ) values in made tea ranged from 30.4% to 73.9% at the pre-harvest interval of 14 days, which were significantly less than 100%. CONCLUSION The accuracy and precision of the developed method were satisfied with the measurement requirements according to the validation results. The dynamic dissipation experiments suggested that diafenthiuron was much easier to dissipate than chlorfenapyr. Moreover, the existence of tralopyril made the half-life of chlorfenapyr significantly increase, indicating that practical application of chlorfenapyr should take careful consideration of its metabolite. Finally, the potential chronic dietary risks of the chlorfenapyr-diafenthiuron mixture to human communities were within the acceptable range. This article is protected by copyright. All rights reserved.