Abstract
This paper presents a modified QuEChERS method to determine 346 pesticide residues in honey by LC/MS-MS and GC/MS-MS. Acetate buffered acetonitrile extraction followed by dispersive SPE clean-up with C18-E, PSA and MgSO4 sorbents were used for sample preparation. This method was validated according to the European Union SANTE/2019/12682 guidelines. Acceptable values were obtained for the linearity, the limit of detection (0.001–0.003 mg/kg), limit of quantification (0.002–0.008 mg/kg), trueness (for the four tested levels, the recovery assays values were between 76 and 112%), precision (RSD ≤20.0%) and measurement uncertainty tests (<50%). The method was used for the analysis of 100 honey samples from Northern Cyprus and residues of 4 pesticides (coumaphos, thiamethoxam, N-(2,4-dimethylphenyl)formamide, piperonyl butoxide) were quantified in 42 honey samples. Coumaphos (29%) and N-(2,4-dimethylphenyl)formamide (11%) were the residues frequently detected in the samples. N-(2,4-dimethylphenyl)formamide concentrations (0.56 and 0.84 mg/kg) were determined above the MRL limits (0.2 mg/kg) in two samples. This study shows that LC/MS-MS and GC/MS-MS in combination with modified QuEChERS can be used to routinely scan pesticide residues in honey samples and direct contamination with acaricides/veterinary drugs applied in the treatment of plagues in the hive during honey harvest is the main source of honey pollution in Northern Cyprus.
Disclosure statement
No potential conflict of interest was reported by the authors.