Simultaneous Determination of Pyrethroids Residues in Green Tea Leaves, Processed Tea, Tea Infusion and Spent Tea Leaves

A simple method for the simultaneous determination of pyrethroids residues in green tea leaves, processed tea, tea infusion and spent tea leaves is reported. The target analytes were extracted from selected tea matrices with ethyl acetate followed by dispersive solid phase extraction (d-SPE) based on QuEChERS procedure of clean up with primary secondary amine sorbent to remove co-extractives prior to analysis by gas chromatography with electron capture detector (GC-ECD). The recoveries ranged from 76 to 106 per cent with relative standard deviations below 11 per cent. The limits of quantification for pyrethroids ranged from 0.01 to 0.05 μg g⁻¹. The method was successfully applied to analyse residues of pyrethroids insecticides in actual processed tea samples.