Investigation And Analysis Of Four Fluoroquinolones Residues In Pork And Chicken In Baoding

In this thesis,600 samples of pork and chicken collected in Baoding were taken as the analysis objects,and using high performance liquid chromatography（HPLC）to collect samples of Ciprofloxacin,Dafloxacin,Ennofloxacin and Sarafloxacin in four fluoroquinolones drug residues in quantitative analysis.At the same time,the present situation of four fluoroquinolones residues in pork and chicken in Baoding was investigated,and the harm control measures of veterinary drug residues were explored,so as to provide scientific basis for the monitoring of veterinary drug residues in animal foods in the city.1.By preparing a series of mixed standard solutions with Ciprofloxacin,Ennofloxacin,Sarafloxacin concentrations of 5 ng/m L,10 ng/m L,50 ng/m L,100ng/m L,500 ng/m L,and Dafloxacin concentrations of 1 ng/m L,2 ng/m L,10 ng/m L,20 ng/m L,100 ng/m L,after the analysis by HPLC,the standard curve was drawn and the regression equation was obtained.The linear relation coefficients were all above0.999.2.The sensitivity of the method was determined by preparing blank additive samples with Ciprofloxacin,Ennofloxacin,Sarafloxacin concentrations of 5μg/kg,10μg/kg,20μg/kg,and Dafloxacin concentrations of 1 ng/m L,2 ng/m L,4 ng/m L.The results showed that the detection limit of the first three in pork and chicken were 10μg/kg and the quantitation limit was 20μg/kg,the detection and quantification limits of Dafloxacin were 2μg/kg and 4μg/kg,respectively.3.Six groups of repeatability tests with three concentrations and six parallel were performed on pork and chicken samples.And each group was added with three concentration levels of Ciprofloxacin,Ennofloxacin,Sarafloxacin concentrations of20μg/kg,50μg/kg and 100μg/kg,Dafloxacin concentrations of 4μg/kg,10μg/kg and 20μg/kg,and six parallel samples were taken at each concentration.Then recovery rate is calculated after determination of the relative standard deviation.The results showed that the recoveries of pork and chicken samples were both between60%and 100%,the intra-group relative standard deviation of pork was between 0.8%and 13.5%,the inter-group relative standard deviation was between 5.0%and 11.9%,the intra-group relative standard deviation of chicken was between 0.8%and 11.2%,and the inter-group relative standard deviation was between 4.5%and 12.2%.The results of the two samples were similar and this method was also suitable for the detection of four FQs in chicken.4.500 randomly selected pork samples were divided into 25 groups,and 100chicken samples were divided into 5 groups.One blank control and two parallel quality control samples with Ciprofloxacin,Ennofloxacin,Sarafloxacin concentration of 50μg/kg,Dafloxacin concentrations of 10μg/kg were inserted into each group,and the standard mixed solution with Ciprofloxacin,Ennofloxacin,Sarafloxacin concentration of 25 ng/m L,Dafloxacin concentrations of 5 ng/m L was used as a single point control.The samples were extracted twice by phosphate buffer solution,purified and concentrated by C₁₈solid phase extraction column,and determined by HPLC.No target substance was detected in the blank control samples,and the recovery rate of quality control samples was in the range of 60%-100%.Test results:enrofloxacin was detected in one pork and ciprofloxacin was detected in two chickens,both of which were lower than the maximum residue limit stipulated by the state,and the overall detection rate was 0.50%.5.From 2019 to 2022,the detection rates of four fluoroquinolones were 3.3%,2.5%,0.9%and 0.5%respectively.It can be seen that the detection rate of fluoroquinolones in pork and chicken in Baoding has decreased year by year in recent years.