Determination of pesticide residues in honey: a preliminary study from two of Africa’s largest honey producers

Background: The presence of pollutants in honey can influence honey bee colony performance and devalue its use for human consumption. Using liquid chromatography tandem mass spectrometry (LC-MS/MS), various clean-up methods were evaluated for efficient determination of multiclass pesticide contaminants in honey. The selected clean-up method was optimized and validated and then applied to perform a preliminary study of commercial honey samples from Africa. Results: The most efficient method was primary-secondary amine (PSA) sorbent which was significantly different from the others (P <0.05; average recovery ~94 %) and was applied to analyze 96 pesticide residues in 28 retail honey samples from Kenya and Ethiopia. From our preliminary data, a total of 17 pesticide residues were detected at ~10-fold below maximum residue limit (MRL) established for food products except for malathion which was detected at almost 2-fold above its acceptable MRL. Conclusions: A highly efficient approach for determining pesticide residues in honey with good recoveries was developed. All residue contaminants were detected at levels well below their acceptable MRLs except malathion suggesting that the retail honey analyzed is safe for human consumption. Although PSA clean-up method was selected as the most efficient for cleaning honey samples, omitting the clean-up step was the most economical approach with potential applicability in the food industry.