| Hybrid snakehead (Channa maculata (♀)×Channa argus (♂)) with its good command of heterosis, has been accounted for the majority of snakehead fishes in the breeding process. The snakehead fishes with delicate, delicious meat, a few bones and high dressing percentage, was loved by consumers at home and abroad. Besides, its medicinal value such as spleen diuresis, the blood and the new health tonic nursed back to health, that can be used as a trauma, surgery, and nourishing the aftercare diet materials. Hybrid snakehead has become the major farmed species in the Pearl Rever Delta because of these characteristics of the hybrid snakehead. The large-scale and high density farming have been caused outbreaks of various diseases. In order to pursue economic benefits, the illicit drugs(malachite green, nitrofurans) were used to treat hybrid snakehead parasites or bacterial diseases, this would impact the quality and safety of aqutic products, and threaten seriously on physical and mental health of human beings. In this study, the residues and depuration of malachite green and its metabolite, nitrofurazone and furazolidone metabolites in hybrid snakehead muscle were tested. This law has practical significance in determining the three doping monitoring period and troubleshooting time, which can provide a theoretical basis for the enforcement check of the relevant law enforcement department, hybrid snakehead healthy farming practices and potential risks investigation in the breeding process. In this paper, the residues and depuration of semicarbazide(SEM) in hybrid snakeheads were tested. Hybrid snakeheads were drug-bathed2days with2mg/L nitrofurazone at temperatures of (30.5±0.5)℃.During drug-bath, sampled at0.5、1、2、4、8、12、24、48h,and after drug-bath, sampled at0.5、1、2、4、8、12、24、48、96、192、288、384、480、720、960,1200、1440、1920、2400、2880h,the SEM residue in muscle were measured by high performance liquid chromatography tandem mass spectrometry(HPLC-MS).The results showed that the SEM residue from0.5to48h in hybrid snakehead muscle was increased gradually from (32.58±2.82) to (175.92±18.49) μg/kg during drug-bath. The SEM residue was up to the highest,(108.00±5.86) μg/kg at1h after drug-bath. The residue maintained between(53.60±4.90)and(69.21±5.71)μg/kg from2to48h after drug-bath, and then significantly decreased after48h,and below the detection limit of0.25μg/kg at1440h. The average degradation of SEM in muscle was0.089μg/(kg·h). The results showed that the nitrofurazone of muscle in this experimental condition was degradated after 60days.Meanwhile, the residues and depuration of3-amino-2-oxazolidinone (AOZ) in hybrid snakeheads were analysed. Hybrid snakeheads were fed2%of body weight ration with3‰furazolidone bait at the temperature of30.5±0.5℃,3times a day for5days. And sampled at0.5h、1h、2h、4h、8h、12h、24h、48h、、96h、192h、288h、384h、480h、720h、960h、1200h、1440h、1920h、2400h、2880h、3600h, the AOZ residues in muscle were measured by high performance liquid chromatography tandem mass spectrometry(HPLC-MS).The results showed that the AOZ residues from0.5h to24h in hybrid snakehead muscle increased gradually from (800.18±8.45) μg/kg to (5686.65±11.16) μg/kg, at48h to96h, the residues had little change, maintained between (5420.65±10.81) and (5390.08±7.24) μg/kg, after the administration, below the detection limit of0.5μg/kg at2880h. The results showed that the furazolidone metabolite of muscle in the present experimental conditions was depurated after120days.In addition, the residues and depuration of malachite green (MG) and its primary metabolite leuco-malachite green (LMG) in hybrid snakeheads were tested. Hybrid snakeheads were drug-bathed2days with200μg/L malachite green and large size hybrid snakehead at an average weight of (200±10) g were exposed to malachite green at a nominal concentration of200μg/L in pond. During drug-bath, seed sampled at0.5、1、2、4、8、12、24、48h,after drug-bath, the large size and seed sampled at0.5、1、2、4、8、12、24、48、96、192、、288、384、480、720、960、1200、1440、1920、2400、2880、3600、4320、5040、5760h, the residues of malachite green and leuco-malachite green in large size hybrid snakehead were measured by high performance liquid chromatography tandem mass spectrometry(HPLC-MS/MS), the residues of malachite green and leuco-malachite green in hybrid snakehead seeds were measured by high performance liquid chromatography. During drug-bath0.5to8h, the malachite green of muscle gradually increased to(382.09±11.78) μg/kg,followed by fluctuating gradually decline,48to96h,(31.36±7.13) μg/kg began to drop significantly to(9.73±11.03)μg/kg, changes tended to gentle until192h, the malachite green of hybrid snakehead muscle below the detection of limit after50d. During drug-bath, During drug-bath0.5to24h, the leucomalachite green of hybrid snakehead muscle gradually increased to (4865.71±11.75) μg/kg, after drug-bath,the residue of leuco-malachite green maintained between(1685.56±13.74)μg/kg～(1472±9.09) μg/kg from lto12h, the residue of leuco-malachite green dropped significantly after12h and belowed the limit of detection at40d.The residues of malachite green and leuco-malachite green from0.5h to96h in muscle increased unceasingly and were up to (543.77±22.14) μg/kg～ (220.51±7.93) μg/kg, respectively. The residue of malachite green decreased after96h, below the detection limit of0.5μg/kg at1920h. The residue of leuco-malachite green maintained between (73.72±4.85) μg/kg and (70.33±9.27) μg/kg from288h to480h, significantly decreased to (2.25±0.25) μg/kg at1920h, below the detection limit of0.5μg/kg at5040h. The results also indicated that leuco-malachite green was more slowly degradated than malachite green, which could be used as target analysis in whether malachite green was used in aquaculture. |
PDF Full Text Request