| The aquiculture with big area and high density is positive correlations for diseases. In China, with the development of aquiculture, diseases are getting more and more serious, so antibacterial drugs were often used for prevention and cure. But all kinds of drugs were misused seriously for lack of scientific direction, and as result, the residues of drugs can do very harm to people. After China entrance to WTO, aquatic organisms exported from our country had been rejected constantly by EU, America, Japan and so on for the residues of drugs exceeded the standard. And now, it was been found that the metabolites of some antibacterial drugs in aquatic organisms have the same harm to people as the original, some even serious than the original. So it has become very important to study on the residues and metabolites of antibacterial drugs in aquatic organisms and the technique of using drugs. Our studies focus on the residues of tetracycline, furan, enrofloxacin and sulfanilamide in aquatic organisms by HPLC and HPLC-MS. The safety of antibacterial drugs and its metabolite was evaluated scientifically at the same time. We also explained that how the residues of drugs were influenced by the temperature and others. The results we obtained can enrich and perfect the theory of pharmacokinertic and residues of antibacterial drugs, what's more it can give help to direct the aquiculture with safety and harmlessness. Main results obtained are listed as below:The residues and elimination of tetracycline (TC) and oxytetracycline (OTC) in muscles,liver and serum of Tilapias were studied after a single oral administration at a dose of 50mg/kg in different temperature. The results show that the residues of TC and OTC are mainly in liver, the muscle's is the least. After 216h the concentration of TC and OTC in muscles decreased to 0.1mg/kg. The rate of eliminations of TC and OTC are very slow in Tilapias. The rate of elimination is getting more and more slowly with the falling of temperature, and the elimination half-life is prolonged. The elimination half-life of TC and OTC in 23℃ is 1.79 and 1.68 times than which in 28℃ respectively.The residues of enrofloxacin and its metabolite in Jifu Tilapia and Penaeus chinensis were first studied after a single oral dose of 50mg/kg for 7 days,and the withdrawal time was made at the same time. The results show that the metabolite of enrofloxacin in Tilapia and Penaeus chinensis both is ciprofloxacin. Because of different animal, the rate of metabolizing in Tilapia is more higher than that in Penaeus chinensis, The maximal concentration of enrofloxacin and ciprofloxacin in Tilapia are 3.61μg/g, 0.22 μg/g ,but which in Penaeus chinensis are 1.68μg/g,0.066μg/g respectively. The predicted withdrawal time for Tilapia is 22d, and Penaeus chinensis is 12d.The residues of furazolidone [3-(5-nitrofurfurylidenamino)-2-oxazolidinone] and its main metabolite in tilapias were first studied by HPLC/MS. The results show that the main metabolite of furazolidone in tilapias is 3-amina-2-oxazolldinone (AOZ). After oral dose of 30mg/kgfor 7 days, the maximum level of furazolidone in tilapias was 413.00μg/kg after 6h, but that of AOZ reached maximum 31.15μg/kg when stopping giving drug. The concentration of furazolidone was lower than 10μg/kg after 24h, but that of AOZ was just lower than 1μg/kg after 528h. The results show that AOZ is very hard to eliminate compare to furazolidone. In view of AOZ is very hard to eliminate, the predicted withdrawal time of furazolidone for tilapias was 22d at least in this condition.The residues and elimination of Sulfaquinoxaline in muscles and liver of Scophthatmus maximus were first studied after a single oral administration at a dose of 40mg/kg. The results show that the main residues of Sulfaquinoxaline is in the liver of Scophthatmus maximus, and The rate of elimination is very slow. The maximum level of Sulfaquinoxaline in the muscle and liver are 0.696 μg /g, 0.778 μg /g respectively. The predicted withdrawal was 10d at least in thi...
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