| Tea, as one of the main export commodities, is of the greate importance in international market. More restrictive health standards, espesally on residue of pesticides were established with expression in more determination items and lower detection limit in some tea import countries. The problem of residue of pesticides in teas caused widespread public alarm and a falling export in China. Therefore, considering the key problems of tea safety and challenges we are facing since entry into the World Trade Organization (WTO), it is of vital importance to establish some accurate, quick, and sensitive determination methods for pesticide residues, which is significative for the safe production situation in teas, improving teas quality, breaking trade barrier, and protecting health of citizen.The aim of this study was to establish a method to measure residue of71pesticides in teas including organophosphorus, organochlorine and pyrethroid, etc with the pretreatment of extraction and purification.(1) Different extracting and separateing methods were used in accordance with different teas for the requirement of organophosphorus, organochlorine and pyrethroid measuration.(2) The results of recovery tests showed that, the recovery of organophosphorus is72.67%-102.5%, the relative standard deviation is0.33%-8.79%, and the recoveries of organochlorine and pyrethroid are72.02%-119.23%, the relative standard deviation of them is0.19%-9.56%.(3) The detection limits of organophosphorus, organochlorines and pyrethroids (except for triadimenol and flutriafol) are0.2μg/kg～60μg/kg.In lack of some other confirmatory analysis of pesticide residues, for example:GC-MS, GC temperature on dual columns is a simple and quick method. According to this, GC temperature on dual columns was used for the confirmatory analysis of pesticide residues to establish a confirmatory analysis method. Meanwhile, GC-MS was also used for confirmatory analysis of pesticide residues in teas. |
