Comparation study on the metabolism destination of neonicotinoid and organophosphate insecticides in tea plant (Camellia sinensis L.).

The absorption, distribution, metabolism and primary risk evaluation data of four neonicotinoids and two organophosphate insecticides in tea plant (Camellia sinensis L.) were compared. 22 neonicotinoid metabolites and 2 organophosphate metabolites were identified. The amount ratio of each neonicotinoid metabolite to its corresponding parent (M/P) was lower than 0.076 in the treated time. The organophosphates (omethoate and methamidophos) increased sharply, with M/P as high as 1.111 and 0.612. The risks evaluation of insecticides and their metabolites in treated leaves on day seven showed that the chronic risk was from the lowest 0.0759 (clothianidin) to highest 43.6409% (dimethoate), and the acute risk was highest 0.0370 for all targets. The calculated combined toxicity of leaves treated with acephate reached 1.5 folds in mature, 1.5 folds in tender leaves than no metabolites, and which of dimethoate were 2.1 folds in mature and 3.7 folds in tender leaves.