Analysis of residues of veterinary drugs – nitroimidazoles in rare honey species
Authors: Mišetić Ostojić Dijana , Pavlešić Tomislav , Džafić Natalija , Boljkovac Begić Barbara , Bilandžić Nina , Kvrgić Kristina 
Published: November 2024

Honey is a natural product producedby honeybees valued for its nutritional andhealth benefits. However, contaminationwith veterinary drug residues, such as ni-troimidazoles (NMZ), poses a health risk toconsumers. Nitroimidazoles, banned in theEuropean Union due to their carcinogenicand genotoxic properties, have been mis-used in beekeeping to treat diseases suchas nosemosis. The aim of this study was todetect nitroimidazole residues in rare uni-floral honey species from Croatia, Ailanthusaltissima (Mill) Swingle and Mentha spp.,using a validated ultra-performance liquidchromatography-tandem mass spectrometrymethod. Although the applied method wasoriginally developed for the determinationof NMZs in poultry muscle and eggs, the re-sults of the validation study show that it isalso suitable for determination in honey withsome modifications. For all analytes, the de-cision limit and detection capability valueswere between 0.33 and 0.71 µg/kg, which isbelow the minimum method performancerequirement for NMZs in honey of 1 µg/kgset by the European Union Reference Labo-ratories. Ten nitroimidazoles were analysedin 11 honey samples and no residues weredetected, confirming compliance with Eu-ropean regulations. These results are in linewith broader studies showing rare NMZ con-tamination in the global honey market. How-ever, they emphasise the need for continuousHoney is a natural product producedby honeybees valued for its nutritional andhealth benefits. However, contaminationwith veterinary drug residues, such as ni-troimidazoles (NMZ), poses a health risk toconsumers. Nitroimidazoles, banned in theEuropean Union due to their carcinogenicand genotoxic properties, have been mis-used in beekeeping to treat diseases suchas nosemosis. The aim of this study was todetect nitroimidazole residues in rare uni-floral honey species from Croatia, Ailanthusaltissima (Mill) Swingle and Mentha spp.,using a validated ultra-performance liquidchromatography-tandem mass spectrometrymethod. Although the applied method wasoriginally developed for the determinationof NMZs in poultry muscle and eggs, the re-sults of the validation study show that it isalso suitable for determination in honey withsome modifications. For all analytes, the de-cision limit and detection capability valueswere between 0.33 and 0.71 µg/kg, which isbelow the minimum method performancerequirement for NMZs in honey of 1 µg/kgset by the European Union Reference Labo-ratories. Ten nitroimidazoles were analysedin 11 honey samples and no residues weredetected, confirming compliance with Eu-ropean regulations. These results are in linewith broader studies showing rare NMZ con-tamination in the global honey market. How-ever, they emphasise the need for continuousmonitoring, especially as the possible use ofbanned NMZs in honey production cannot becompletely ruled out. Future studies shouldalso investigate the transfer of NMZs frombeeswax to honey, emphasising the impor-tance of good beekeeping practises to avoidcontamination.monitoring, especially as the possible use ofbanned NMZs in honey production cannot becompletely ruled out. Future studies shouldalso investigate the transfer of NMZs frombeeswax to honey, emphasising the impor-tance of good beekeeping practises to avoidcontamination.