[Determination of serum copper and zinc in different chemical forms by graphite furnace atomic absorption spectrometry with ethanol-EDTA precipitation method].

A simple and reliable method was developed for the determination of serum copper and zinc in different chemical forms by graphite furnace atomic absorption spectrometry(GFAAS) with ethanol-EDTA precipitation.The serum and ethanol were mixed with volume ratio 1∶2.The mixture was incubated at 70 ℃ and ultra-centrifuged to precipitate proteins.Zinc and copper can be released from albumin after EDTA treating.Thus,macroglobulin-zinc,ceruloplasmin-copper,and albumin-bound zinc or copper could be determined by two proposed precipitation steps.The determination limit of copper(3σ) was 1.2 μg·L-1 and the recovery was 92.3%-104%,while the determination limit of zinc(3σ) was 0.098 μg·L-1,and the recovery was 90%-107%. This two-step precipitation method can be used to determine serum zinc and copper in various chemical forms in tumor,Wilson patients and heathy human.