Persistence Study of Thiamethoxam and Its Metabolite in Kiwifruit for Establishment of Import Tolerance

Abstract

BACKGROUND: Pre-harvest interval and decline pat-tern of thiamethoxam were determined in kiwifruit using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The study was carried out to propose import tolerance using OECD maximum residue limit (MRL) calculator for the export promotion of kiwifruit to Taiwan. METHODS AND RESULTS: The thiamethoxam residue in kiwifruit was determined by using the LC-TriQ-MS/ MS with the analytical process to set up the import tolerance under greenhouse conditions for Taiwan. Excellent linearity was observed for all of the analytes with a determination coefficient (R 2 )≥0.99. The limit of quantification was determined to be 0.01 mg/kg for both thiamethoxam and clothianidin in kiwifruit. Linearity was determined from the co-efficient of determinants (R 2 ) obtained from the seven-point calibration curve. The standard calibration curve showed as follows; 1) Site 1 (Gimje): y =