Residues, fate and risk assessment of spirotetramat and its four metabolites in pineapple under field conditions

The aim of this study was to investigate the fate, terminal residues and risk assessment of spirotetramat and its four metabolites in pineapple and pineapple pulp samples. To achieve this goal, a simple, efficient and sensitive method based on QuEChERS technique was developed using LC-MS/MS. The limit of quantification was 0.01 mg/kg for all the target analytes with the average recoveries ranging from 77% to 109%. The validated method was successfully applied to investigate the fate and terminal residue of spirotetramat and its four metabolites in pineapple and pineapple pulp samples in China. The dissipation dynamics of spirotetramat in pineapple were investigated according to first-order kinetics and the calculated half-lives were 4.6 and 2.3 days in the two sampling locations. After two or three applications at the doses of 80 to120 mg a.i./kg, the highest spirotetramat residue (sum of spirotetramat and its four metabolites) that detected in pineapple and pineapple pulp samples were 0.203 and 0.064 mg/kg. The dietary risk assessment of spirotetramat in pineapple was assessed by risk quotients and the calculated risk quotient value was found to be far below 100%, indicating a low health risk to the consumers. As there was no recommended MRL value in pineapple in China, these results should be useful for safe and reasonable usage of spirotetramat in pineapple in China.