| A high performance liquid chromatography-fluorescence detection for the determination of danofloxacin,sarafloxacin and difloxacin residue in black-bone chicken.The residue depletion of danofloxacin,sarafloxacin and difloxacin in black-bone chicken were also investigated in this paper.The study was carried out by mixing 20% lactic acid with 70% acetonitrile as the tissue extract.The mixture was centrifuged and concentrated by steam.The volume was adjusted to 2 mL with water,and the water was saturated with N-hexane.The column choose Agilent 5 TC-C18(250 mm × 4.6 mm,5μm),The mobile phase was0.05 mol / L phosphoric acid / triethylamine solution(pH 2.4)-acetonitrile(80:20)at flow rate of 0.8 mL/min,and the column temperature at 25 ℃,and injection20μL,Fluorescence excitation wavelength was 280 nm,and emission wavelength was450 nm.The results showed that the calibration curves of danofloxacin,sarafloxacin and difloxacin were linear in the range of 0.01~0.2 μg/mL.The blank tissue was added at high,medium and low concentration,the recovery rate was 75.2% ~ 94.3%.The coefficient of variation was 0.5% ~ 17.6%,and the coefficient of variation was 1.1%~ 11.1%.The limit of detection(LOD)of danofloxacin in the muscle of black-bone chicken was 0.2 μg/kg and the limit of quantificatin(LOQ)was 0.5 μg/kg.The detection limit of sarafloxacin was 2 μg/kg,and the limit of detection was 5μg/kg.The detection limit of difloxacin was 1 μg/kg,and the limit of detection was 2μg/kg.The detection limit of danofloxacin in liver and sebum was 0.25 μg/kg and thelimit of quantification was 0.5 μg/kg.The detection limit of sarafloxacin was 2 μg/kg,the limit of detection was 4 μg/kg and The detection limit of difloxacin was 1 μg/kg,the limit of detection was 2 μg/kg.The method is simple,accurate and sensitive,and is suitable for the determination of the content of fdanofloxacin,sarafloxacin and difloxacin in tissue of black-bone chicken.The rabbits were randomly divided into 2 groups,110 rats in each group and 20black-bone chicken.Three weeks of age according to the danofoxacin 50 mg/L,continuous drinking for 3 days;according to difloxacin count 100 mg/L,continuous drinking for 5 days;by sarafloxacin 50 mg/L,continuous drinking 5 days.The dose was 20 mg/kg.bw.for sarafloxacin.Eight animals of danofloxacin and difloxacin were slaughtered after administration at 4hours and 1,3,5,7,10,14,21,28,35,42,49 days respectively.The contents of sebum,muscle,liver,kidney,myocardium and lung were measured at each time point for the determination.The sarafloxacin group was treated with 6 hours,12 hours,24 hours and 3,7,14,21,28,35,4 days and so on.Each time point mixed drink slaughtered 4 animalsand irrigation slaughtered 3animals,take sebum,muscle,liver,kidney and other tissue content determination.According to the results of the test:Danofloxacin in a tissue to eliminate the situation: After 35 days withdrawal in the muscle and After 1 day of withdrawal in the liver and After 35 days of withdrawal in the kidney and After 49 days in the lungs,the detection was lower than the MRL;and the detection rate was much higher than that of MRL at 49 days after drug withdrawal in the sebum;and in the muscle stomach was lower than that of MRL at 28 days after drug withdrawal.Difloxacin in a tissue to eliminate the situation: After 35 days withdrawal in the muscle and After 35 days of withdrawal in the kidney and After 35 days of withdrawal in the muscle stomach,the detection was lower than the MRL;liver were lower than the MRL;and the detection rate was much higher than that of MRL at 49 days after drug withdrawal in the sebum;The average amount of tissue and drug residues was 535.7 μg / kg,which was slightly lower than that of MRL at 49 days after drug withdrawal in the lungs.Sarafloxacin in a tissue to eliminate the situation: The average detection rate was 41.3 μg / kg after 48 days of withdrawal in the muscle.After 7 day of withdrawal in the liver,the detectionamount was lower than that of MRL;and 48 days after in the sebum Higher than that of MRL;After 14 days of withdrawal in the kidney,the detection amount was lower than that of MRL.The results showed that the residuals of danofloxacin and difloxacin in the tissues of black-bone chicken were as follows: sebum,lung,kidney,muscle,stomach,muscle,liver.Sarafloxacin were as follows: sebum,muscle,kidney,liver.Tissue eliminate time from high to low sebum,lungs,muscles,muscles,kidneys,liver,Sarafloxacin as muscle,sebum,liver,kidney.Drugs in the sebum in the residual amount of the largest,easy to accumulate and easy to eliminate;followed by the lung,muscle and muscle stomach similar to the residual and elimination rate is similar;kidney residuals are large,but the eliminate time shorter than other tissues Two drugs in the kidneys to eliminate fast;early to eliminate the liver fast and rapid,is the danoxacin and difloxacin one of the main metabolic organs.Sarafloxacin compared with danofloxacin and difloxacin is different from the time of tissue eliminate and elimination of different speed,the slowest metabolism of muscle and followed by sebum;liver eliminate time longer than the kidneys. |
