Rapid preparation of melamine based magnetic covalent triazine polymers for highly efficient extraction of copper(II), chromium(III) and lead(II) ions from environmental and biological samples

•Melamine based magnetic covalent triazine polymers (MCTPs) was rapid synthesized.•MCTPs showed good affinity and fast adsorption kinetic toward Cu2+, Cr3+ and Pb2+.•A method of MSPE-GFAAS based on MCTPs was proposed for analysis of trace metals.•The proposed method is simple, sensitive and highly efficient.•Trace metals in environmental and biological samples was analyzed.