氟苯尼考及其代谢物氟苯尼考胺在鸡肌肉中的残留消除规律

本试验旨在研究氟苯尼考及其代谢物氟苯尼考胺在鸡肌肉中的残留消除规律。鸡肌肉样品经丙酮、二氯甲烷提取,饱和正己烷脱脂,氮吹仪吹干浓缩后,以乙腈-磷酸二氢钠溶液(0.01mol.L-1,含0.005mol.L-1十二烷基硫酸钠和0.1%三乙胺)(体积比35∶65)为流动相,流速为1.0mL.min-1,在激发波长225nm、发射波长285nm处用高效液相色谱荧光检测器检测。结果:测得鸡肌肉中氟苯尼考、氟苯尼考胺的检测限分别为1.5和0.5μg.kg-1(S/N=3)、定量限分别为5和2μg.kg-1(S/N=10)。各试验组京海黄鸡分别按体质量以25.0、50.0和100.0mg.kg-1.d-1剂量给药,每天1次,连续5d内服给药后,休药第1天时,鸡肌肉中氟苯尼考及其代谢物氟苯尼考胺的残留量均达到峰值,且残留量随给药剂量的增大而增大,随休药期的延长而降低。休药第7天时,鸡肌肉中氟苯尼考及其代谢产物氟苯尼考胺的总残留量均低于MRLs(100μg.kg-1);休药第11天时,鸡肌肉中氟苯尼考及其代谢产物氟苯尼考胺的总残留量均低于检测限;氟苯尼考、氟苯尼考胺在鸡肌肉中的残留量及其总残留量均与给药剂量呈正相关。

Florfenicol and Its Metabolite Florfenicol Amine Residue Depletion in Chicken Muscle

A study on florfenicol(FF) and florfenicol amine(FFA) residue depletion was conducted in chicken muscle.FF and FFA were extracted from chicken muscle with acetone and dichloromethane.The extract solution was degreased in n-hexane saturated with acetonitrile,dried in nitrogen evaporator and residues were dissolved in mobile phase.FF and FFA were determinated by high performance liquid chromatography(HPLC) with fluorescence detector.The mobile phase was acetonitrile-monosodium phosphate solution(0.01 mol·L-1,containing 0.005 mol·L-1 SDS and 0.1% triethylamine)(35:65 by volume),the flow rate was 1.0 mL ·min-1.The fluorescence detection was with an excitation wavelength of 225 nm and an emission wavelength of 285 nm.Result were as follows: The limits of detection(LODs)of FF and FFA were 1.5 μg·kg-1(S/N=3) and 0.5 μg·kg-1(S/N=3),respectively.The limits of quantitation(LOQs)were 5 μg·kg-1(S/N=10)and 2 μg·kg-1(S/N=10),respectively.After the chickens orally administered successively FF capsules of 25.0 mg·kg-1,50.0 mg·kg-1 and 100.0 mg·kg-1 of body weight one time every day for 5 days,respectively,at the first withdrawal day,the maximum residues of FF and FFA were detected.The residues were rising with the dosage and reducing with the withdrawal time.At the 7th withdrawal day,the total residues of FF and FFA were all lower than the MRLs(100 μg·kg-1);and all lower than the lowest LOD at 11th withdrawal day.The residues and total residues of FF and FFA in chicken muscle were all positively correlated with FF orally administered doses.