Analysis of sulfonamides, fluoroquinolones, tetracyclines, triphenylmethane dyes and other veterinary drug residues in cultured and wild seafood sold in Montreal, Canada

Abstract

Freshwater and marine seafood products purchased in Montreal, Canada, were screened for diverse veterinary drug residues including sulfonamides and potentiators, macrolides, lincosamides, nitrofurans, nitroimidazoles, amphenicols, quinolones and fluoroquinolones, one triphenylmethane dye and its leuco-metabolite, and tetracyclines. QuEChERS extraction ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) was validated in three model matrices (fatty fish, lean fish, and shrimp edible meat). Method detection limits were in the range of 0.002–3 μg/kg, and the accuracy of matrix-matched extracted calibrants was generally within acceptance criteria. The aquaculture or wild-caught samples of pangasius (basa), cod, salmon, sole, tilapia, trout, white shrimp and giant tiger prawn originated from Canada, China, India, Southeast Asia (Indonesia, Thailand, Vietnam), and other regions worldwide. Overall, 38 % of the tested fish and shrimp samples had detectable residues of at least one veterinary drug or metabolite, and 25 % were not compliant to Canadian guidelines. Leucomalachite green was detected across various sample types (detection frequency: 13 %; maximum: 0.9 μg/kg). Other detected compounds (2–11 % of samples) included tetracycline (maximum: 36 μg/kg), 4-epi-oxytetracycline (18 μg/kg), oxytetracycline (13 μg/kg), metronidazole (13 μg/kg), sulfamethazine (4.8 μg/kg), sulfamethoxazole (4.2 μg/kg), trimethoprim (0.59 μg/kg), florfenicol (0.27 μg/kg), flumequine (0.21 μg/kg), enrofloxacin (1.6 μg/kg), and ofloxacin (0.52 μg/kg).