Studies on the residue and degradation rules of nitrofurazone metabolites in hybrid snakehead (Channa maculata (♀) × Channa argus (♂)).

In this paper,the residues and depuration of semicarbazide(SEM) in hybrid snakeheads(Channa maculata(♀) ×Channa argus(♂))were tested.Hybrid snakeheads were drug-bathed 2 days with 2 mg/L nitrofurazone at temperatures of(30.5±0.5) ℃.During drug-bath,the samples were collected at 0.5,1,2,4,8,12,24,48 h,and at 0.5,1,2,4,8,12,24,48,96,192,288,384,480,720,960,1 200,1 440,1 920,2 400,2 880 h after drug-bath,and the SEM residues in muscle were measured by high performance liquid chromatography tandem mass spectrometry(HPLC-MS).The results showed that the SEM residue from 0.5 to 48 h in hybrid snakehead muscle increased gradually from(32.58±2.82) to(175.92±18.49) μg/kg during drug-bath.SEM residue was found to be the highest,(108.00 ±5.86) μg/kg at 1 h after drug-bath.The residues ranged between(53.60±4.90)and(69.21±5.71) μg/kg from 2 to 48 h after drug-bath but significantly decreased after 48 h,which was below the detection limit of 0.25 μg/kg at 1 440 h.The average degradation of SEM in muscle was 0.089 μg/(kg·h).The results showed that the nitrofurazone of muscle in this experimental condition was degraded after 60 days.