Abstract:The trichlorfon, dichlorvos, and coumafos are commonly used as organophosphorus pesticides to control pests or natural enemies of bees, but they easily contaminate the honey. A simultaneous determination method for trichlorfon, dichlorvos and coumafos residues in honey is developed by high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS). Samples are extracted with ethyl acetate and concentrated extracts, and then the residue is dissolved by methanol, and separated by HPLC, detected by electrospray ionization (ESI)-MS/MS with multiple reaction monitoring mode (MRM). It is found that the linear ranges of the three organophosphate pesticides are 20~500 μg/L with correlation coefficients over 0.994, the detection limits (LODs) are 0.1 μg/kg and the limits of quantification (LOQs) are 4 μg/kg for all of the three pesticides. The average recoveries of the three pesticides in spiked honeies at concentration levels of 10~40 μg/kg range from 78.5% to 96.8%, and the relative standard deviations are in the range of 9.1%~13.1%.