Determination of Chlorfenapyr and Its Metabolite in Fruits and Vegetables by Ultra Performance Liquid Chromatography and Its Application in Residual Evaluation of Cabbage

KeyWord:ultra performance liquid chromatography  chlorfenapyr  tralopyril  residual evaluation  fruits  vegetables

Abstract:

      An ultra performance liquid chromatography£¨UPLC£© with solid phase extraction was developed for the simultaneous determination of chlorfenapyr and its metabolite tralopyril in fruits and vegetables£®The validation results showed that there was a good linear relationship in the range of 25£­5 000 ng¡¤mL-1 with correlation coefficients£¨r2£© of 0.997£­1.000. The average recoveries at three spiked levels of 0.05£¬1 and 2 mg¡¤kg£­1 ranged from 84.6% to 111%£¬with relative standard deviations£¨RSD£¬n = 5£© of 1.6%£­14%£®The limits of quantitation£¨LOQ£© were both 0.05 mg¡¤kg£­1 for the two target compounds. Field trials were carried out in 12 areas nationwide in 2020£¬after 360 g¡¤L-1 chlorfenapyr suspension was sprayed once at 20 mL/mu£¨125.28 g a.i./ha£©£¬the dissipation of chlorfenapyr in cabbage accorded with the first-order kinetics equation£¬and the half-life period was 4.1£­11.0 d£®When the sampling intervals were 14 d and 21 d£¬the residual levels of chlorfenapyr in cabbage were lower than 0.05£­0.488 mg¡¤kg£­1 and lower than 0.05£­0.370 mg¡¤kg£­1£¬respectively£¬while those of tralopyril in cabbage were both lower than 0.05 mg¡¤kg£­1£®Based on the MRLs of China£¬14 d was selected as the post harvest interval. The dietary risk assessment revealed that the national estimated daily intake of chlorfenapyr£¨definition for dietary risk assessment£© was 1.28 mg£¬accounting for 67.7% of the acceptable daily intake£¬which showed there was no significant dietary risk to residents' health.