GC/MS法研究鸡体内三聚氰胺的残留及代谢规律

Determination of residues and metabolism of melamine in chicken using GC/MS

研究建立了气相色谱-质谱法（GC／MS）测定鸡体内三聚氰胺残留的方法。样品以10g／L三氯乙酸溶液提取，CleanertPCX固相萃取柱净化，50℃水浴中氮气吹干后衍生化。以GCJMS选择99，171，327，3424个碎片离子进行定性定量分析。三聚氰胺在0．05～2．50mg／L呈线性（R0为0．999），鸡蛋中3种不同添加浓度0．05，0．10和0．50mg／kg下三聚氰胺平均回收率分别为84．71％，88．12％，92．62％；相对标准偏差分别为10．57％，7．12％，6．92％；样品中最低检测限（S／N=3）为0．005mg／ks。采用该方法研究三聚氰胺在鸡体内的代谢机理，结果表明：在较高饲喂浓度（1000mg／kg）时，用药后，鸡体内三聚氰胺蓄积量逐渐增加，最高蓄积浓度为16．465mg／kg，但停药后代谢又非常快。

A method for determination of melamine residues in chicken by gas chromatography-mass spectrometry （GC/MS） was developed. The melamine was extracted from chicken samples by employing 10 g/L trichioroacetic acid solution, the cleaning procedure was performed by Cleanert PCX solid phase extraction cartridge. The extracts were warmed with water at 50℃ and blowed with nitrogen until it got near to dryness and then it was derivated. Retention time and specific ions were used to identify melamine. The selective fragments were m/z 99,171,327,342, respectively. The calibration curve of melamine was linear （correlation coefficient： 0. 999） in the range of 0.05 - 2.5 mg/L. The average recovery rates （ at 0.05,0.10 and 0.50 mg/kg） were 84.71%, 88.12%, 92.62%, respectively; while the relative standard deviations （RSD） of the method were 10.57 %, 7.12%, 6.92 %, respectively; and the limit of detection （LOD）, defined in terms of 3 times baseline nosie was 0.005 mg/kg. The developing method was apphed to study the metabohc behaviour and mechanism of melamine in chicken. The results indicated that the residual contents of melamine was increased gradually in chicken fed with higher dosage （1 000 mg/kg）, and the highest content of melamine was 16.465 mg/kg. However, the content of melamine in chicken was reduced immediately after feeding withdrawal.