Method Validation for Detection of Afidopyropen and M440I007 in Tea.

A TPT cartridge-based method for the solid phase extraction of afidopyropen and M440I007 from tea matrices was developed in this study. Extraction and clean-up conditions, including the composition, volume and temperature of elutions were optimized to achieve the best results. Both targets were extracted using water and acetonitrile, with a water:acetonitrile (v/v) ratio of 4/10 for fresh leaves and 8/10 for dried tea, which were then cleaned with a Cleanert TPT column and analyzed using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Both analytes demonstrated excellent linearity with the correlation coefficient above 0.998. The optimized analytical method offered the limits of quantifications (LOQs) of 0.005 mg·kg , 0.005 mg·kg , and 0.002 mg·kg (converted to dried tea) in fresh tea shoots, dried tea and tea infusion for both targets, respectively. Average recoveries of afidopyropen and M440I007 ranged from 79.0 to 101.5%, with relative standard deviations (RSDs)≤14.7%. The results showed that the determining method for these insecticides in tea matrices was practical and efficient. This article is protected by copyright. All rights reserved.