Synthesis and application of core-shell complex-imprinted polymer for the solid-phase extraction of melamine from dairy products

A core-shell complex-imprinted polymer (CIP) was synthesized and evaluated for selective extraction of melamine from dairy products. The CIP synthesis based on surface modification of home-made silicon microspheres was conducted via a metal complex as functional monomer, ethylene glycol dimethylacrylate as cross-link and melamine as template. The resulting CIP was characterized by SEM and Fourier transform infrared spectroscopy. When the amount of silica microspheres was 100 mg and the molar ratio of copper(II) methacrylate to EDGMA was 1:10, well-dispersed particles were obtained. The complex-imprinted SPE condition was optimized and the maximum enrichment factor of melamine can be up to 40. The reliability of complex-imprinted SPE for extraction and enrichment of melamine was investigated and proved by using spiked samples including milk and milk powder with the recoveries ranging from 87 to 92%.