The effect of cooking on veterinary drug residues in food: Nicarbazin (Dinitrocarbanilide component)

Abstract

The change of concentration of residues of the marker compound for the anti-coccidial drug nicarbazin, N,N′-bis(4-nitrophenyl)urea (dinitrocarbanilide, DNC), was investigated in model oil and aqueous solutions and in chicken muscle and egg. In model aqueous solutions, DNC decreased rapidly in concentration upon heating followed by a much more gradual decomposition. The curves produced when this information was plotted were not typical of exponential decay. In model cooking oil solutions, DNC generally showed a slower decrease in concentration over time when compared with aqueous solutions. DNC residues in egg were stable to microwave cooking and residues in chicken muscle were stable to stewing and microwaving. Other cooking procedures led to a decrease in amount of DNC by 22% to 48% of the total amount of analyte present. Only a small amount (< 2%) of residue leached with juices which exuded as the food was cooked.

Keywords:

• Nicarbazin
• dinitrocarbanilide cooking
• HPLC
• residues

Acknowledgements

Tissue from chickens treated with nicarbazin was provided by the Veterinary Sciences Division of the Department of Agriculture and Rural Development, Northern Ireland. This work was funded by the Veterinary Medicines Directorate of the UK Department for Environment, Food and Rural Affairs.