Simultaneous Determination of 70 Pesticide Residues in Coffees by Gas Chromatography-mass Spectrometry

An efficient and sensitive method for simultaneous determination of 70 pesticide residues in coffees has been established and validated. The multiresidue analysis of the pesticides in coffees involved extraction with ethyl acetate, clean-up using gel permeation chromatography (GPC) and solid-phase extraction (SPE), and subsequent identification and quantification of the selected pesticides by gas chromatography-mass spectrometry (GC-MS). and then quantified with an external standard method. Recoveries of pesticides ranged from 61% to 127% at the spiked level of 0.005-2.5 mg/kg, while the relative standard deviation was between 2% and 17%. In addition, the limits of determination (0.005 mg/kg to 0.5 mg/kg) revealed that simultaneous determination of multi-residues in coffees was possible.