Analysis of veterinary drug residues in fish and shrimp composites collected during the Canadian Total Diet Study, 1993–2004

Abstract

Thirty shrimp, marine fish, freshwater fish, and canned fish composite samples collected and prepared as part of the Canadian Total Diet Study were analysed for 39 different veterinary drug residues. The analyses were undertaken to obtain baseline data that could be used to estimate the dietary exposure of Canadians to these residues. The most frequently observed residue was AOZ (four out of 30 samples), the metabolite of furazolidone, at a range of 0.50 to 2.0 ng g⁻¹ wet weight. Other residues detected included enrofloxacin (three samples; 0.3–0.73 ng g⁻¹), leucomalachite green (three samples; 0.73–1.2 ng g⁻¹), oxolinic acid (two samples; 0.3–4.3 ng g⁻¹), AMOZ (the metabolite of furaltadone; one sample; 0.40 ng g⁻¹), chloramphenicol (one sample; 0.40 ng g⁻¹), and SEM (the metabolite of nitrofurazone; one sample; 0.8 ng g⁻¹). The results of this survey indicate that Canadians are exposed to low ng g⁻¹ concentrations of some banned and unapproved veterinary drug residues via the consumption of certain fish and shrimp.

Keywords:

• Aquaculture
• shrimp
• fluoroquinolone
• malachite green
• nitrofuran
• chloramphenicol
• dietary exposure
• liquid chromatography coupled with tandem mass spectrometry detection (LC/MS/MS)
• antibiotics

Acknowledgements

Funding for this work was provided by the Veterinary Drugs Directorate, Health Canada.