| Thiamphenicol(TAP),also known as sulfone chloramphenicol,is a broadspectrum amphenicol antibacterial drug synthesized by substituting methyl sulfone group for nitro group on the molecular structure of chloramphenicol,which can be used in veterinary clinical treatment of intestinal and respiratory diseases caused by bacterial and mycoplasma infection.It has certain toxic and side effects,mainly reflected in reproductive toxicity,blood toxicity and immune suppression.Long-term consumption of livestock and poultry products with excessive residues of thiamphenicol will lead to anemia,neuritis and other diseases.In order to ensure the safety of food from animals,China has formulated a maximum residue limit of 50 μg·kg-1 for thiamphenicol in edible animal tissues.There are five types of thiamphenicol administered dosage forms approved for clinical use in veterinary drugs in China: powder,tablet,granules,soluble powder,and injection,and granules are only approved for use in chickens.However,there is no data support for the 28-day withdrawal time stipulated by our state.Therefore,the following studies were carried out to comprehensively monitor the residues of amphenicol including thiamphenicol,florfenicol and florfenicol amine in chicken tissues,to study the rule of thiamphenicol granules residual elimination in chickens,and to scientifically assess the current status of amphenicol veterinary drug residues in Henan market.1.A GC-MS method was established for simultaneous detection of TAP,FF and FFA residues in chicken tissues.The limit of detection was 5 μg·kg-1,and the limit of quantification was 10 μg·kg-1.The linear relationship was good in the range of 50 μg·L-1 to 5000 μg·L-1,and the average recoveries were 87.1% to 107.3% at the concentration of 10 μg·kg-1 to 5000 μg·kg-1 in chicken blank tissues.The relative standard deviation in the batch is between 1.2% and 10.9%,and the relative standard deviation between batches is between 1.6% and 9.1%.2.The residual elimination law of thiamphenicol granules in chickens was discovered.It was conducted in accordance with the requirements of Quality management Standard for Veterinary Drug Clinical Trials issued by Ministry of Agriculture of the People’s Republic of China No.2337 and Guidelines for Veterinary Drug Residue Elimination Tests issued by Ministry of Agriculture of the People’s Republic of China No.326.Chickens are given a mixture of 50 mg of thiamphenicol per 1 L of water for 5 days and slaughter to get samples at 4 h,1,3,5,7,10 and 15 days after withdrawal.After the detection and calculated by the withdraw software WT1.4.The results showed that the residual time of thiamphenicol in chicken was detected as1 day in muscle,5.91 days in liver,3.78 days in kidney,1 day in skin + fat and 4.59 days in lung.Therefore,when thiamphenicol granules are administered in the recommended dose of drinking water,the recommended withdraw time is 6 days.3.The residual status of thiamphenicol,florfenicol and florfenicol amine in chicken meat and liver sold in Henan Province was investigated and evaluated.Eight positive samples were detected out of 280 samples collected in supermarkets,farmers’ markets,and slaughterhouses,with a total detection rate of 2.8%.It shows that chicken liver is the sample tissue that should be monitored,and the slaughterhouse and the farmers’ market are the sampling links that should be monitored.Positive sample residues range from 15.1 μg·kg-1 to 33.4 μg·kg-1 and do not exceed the maximum residue limit.It shows that the residual risk of thiamphenicol,florfenicol and florfenicol amine in chicken meat and liver which are sold in the sampling area is low. |
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