Studies On Method Of High Performance Liquid Chromatography(HPLC)for Determination Of Chloramphenicol Resudues And Its Elimination In Eggsv

Chloramphenicol(CAP) was a high-effective broad-spectrum antibiotics used in animals. But it has been found that CAP residues in animal tissues and/or animal products had toxic effects to human body. Therefore, it was necessary to study an analytical method for the elimination of monitoring CAP residues in eggs.A high-performance-Hquid-chromatography(HPLC) method for measuring CAP residues in eggs was established. CAP residues were extracted and pured by acetonitrile, ethyl acetate, and n-hexane from the albumen and yolk of eggs, and then redissolved by mobile phase (acetonitrile: water,20: 80,v/v) and 35% acetonitrile solution respectively at Iml/min flow rate and 25 癈. Detection wave length of UV was set at 280nm. Under the above conditions, the detection limit of CAP in eggs was 0.002fig/g. The calibration curve was linear in the range of 0.002~20ng/g. At 0.002ng/g,0.5ng/g and 20ug/g concentration, the CV% between run was 5.29%, 3.43%, 2.61% for albumen and 5.58%, 3.37%, 1.59% for yolk respectively; the within run CV% was 6.03%, 3.52%, 3.44% (first batch), 6.32%, 3.47%, I.l4%(second batch), 3.90%, 3.73%, 1.10%(third batch), 5.58%, 2.46%, 3.03%(fourth batch) for albumen and 6.53%, 3.83%, 1.34% (first batch), 5.07%, 2.78%, 1.15%(second batch), 5.31%, 2.44%, 1.10%(third batch), 6.14%, 3.28%, 1.25%(fourth batch) for yolk respectively.The recoveries of CAP added to the albumen and yolk at levels of 0.002ug/g, 0.5ug/g and 20ug/g were 105.65 2.41%,94.89 0.95%,91.65 1.13% from albumen, and 104.79 2.70%,83.15 + 1.11 %,80.27 0.41% from yolk respectively. The results showed that this method was sensitive and reliable to measuring CAP residues in albumen and yolk of eggs.Depletion of CAP residues in eggs after oral administration was also studied. Twenty healthy Hailan laying birds were given CAP (lOOmg/kg b.w) consecutively for 12 days. After the end of administration, the CAP in albumen and yolk of eggs collected from these laying birds was detected everyday by the HPLC method above. The concentration-time data of CAP in albumen and yolk were analyzed with MCPKP computer program. On 1 day after the last-administration, the concentrations of CAP in albumen and yolk were 3.61ug/g and 14.51ug/g respectively. On 5 days of the last administration, the concentrations of CAP in albumen and yolk were 0.05|ig/g and 7.17ng/g respectively. On 8 days of the last administration, no CAP residues were detected in egg-albumen, but 0.80^g/g concentration of CAP residues in yolk was still detectable. On 12 days of the last administration, the CAP residues in egg yolk were below the detection limit. The results indicated that CAP residues in eggs were eliminated slowly, especially in yolk.The main pharmacokinetic parameters of CAP residues in eggs were as follow: AUC=9.96mg/l.day,Ti/2P=0.75d in albumen; AUC=81.46mg/l.day,T|/2 p=1.64d in yolk.The results suggested that the pharmacokinetic characteristics of CAP in eggs manifested a rapid absorption of CAP with higher concentration and slower elimination in yolk than that in egg-albumen.