Determination of melamine residues in milk products by zirconia hollow fiber sorptive microextraction and gas chromatography-mass spectrometry.

News stories about the contamination of milk with melamine in China emerged on Sept 11, 2008, and the situation has since become an international health scare. In this work, a novel analytical method based on enrichment and pretreatment of analytes in the milk sample, hollow fiber sorptive extraction and gas chromatography-mass spectrometry has been developed for the rapid analysis of melamine in the dairy products. In the proposed method, melamine in the fresh milk was extracted by zirconia hollow fiber, enriching on zirconia coating of the hollow fiber, and then analyzed by GC-MS. The method validations including linearity, limit of detection, limit of qualification, recoveries at three different concentrations, precision, and repeatability were investigated. It was found that the proposed method provided linear range from 0.001 to 1000 microg/mL (r(2)=0.9997), low detection limit of 0.001 microg/mL, and preferable recoveries at three different concentrations. The obtained results demonstrated that zirconia hollow fiber combined with GC-MS is a simple, rapid and solvent-free method for the analysis of melamine in the dairy products.