建立两步沉淀蛋白质-石墨炉原子吸收法测定血清中非蛋白结合铜和锌的方法。无水乙醇以2：1与血清混合后，再经70℃温度变性处理，可将蛋白质完全沉降。用氘灯校正背景，石墨炉原子吸收法进行测定，方法检测限：Cu，1.2μg·L^-1，Zn，0.098μg·L^-1。回收率：Cu，92.3％-104％，Zn，为90％-107％。利用此方法测定了肿瘤患者血清中游离铜与锌，并与健康人作了对比。

A method was developed for the determination of trace free copper and zinc in serum sample by GFAAS after two-step precipitation. The serum and ethanol were mixed with volume ratio of 1:2. The mixture was subsequently denatured at 70 ℃ and centrifuged to precipitate proteins. The determination, limit of copper (3σ) was 1.2μg ·L^-1 and the recovery was 92. 3%- 104%, and the determination. Limit of zinc(3σ) was 0. 098μg ·L^-1 and the recovery was 90%-107%. This two-step precipitation method can be used to determine non-protein-bound copper in tumor patients and healthy people.