Abstract: 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 S／L trichioroaeetic acid solution，the cleaning procedure was performed by Cleanert PCX solid phase extraction cartridge．Th e 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 coeficient：0．999)in the range of O．05—2．5 ms／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 ms／kg．The developing method Was applied to study the metabolic behaviour and mechanism of melamine in chicken．Th e 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 ofmelamine Was 16．465 ms／kg．However，the content of melamine in chicken was reduced immediately after feeding withdrawal．

Key words: chicken, melamine, residual, gas chromatography—mass spectrome try(GC／MS)