Ion-exchange chromatography (IC) in the determination of serum transition metals and its clinical application

The reproducibility of ion-exchange chromatography (IC) (Dionex Bio-LC) in measuring the serum transition metals Cu and Zn was found to be fairly good (CV = +/- 2.1% and +/- 2.7% within runs, and +/- 2.5% and +/- 4.3% among runs for Cu and Zn, respectively). For clinical application, sera from 20 normal volunteers and 20 patients with cancers of the digestive tract (10 early and 10 late stage cases) were analyzed. The means of serum Cu (15.54 +/- 0.31 mumol/L) and serum Zn (14.84 +/- 0.31 mumol/L) in normal volunteers were very close to the values previously determined by atomic absorption spectrophotometry in our laboratory. In the group of late stage cancer patients, the means of serum Cu (24.18 +/- 0.63 mumol/L) and the Cu/Zn ratio (1.97 +/- 0.07) were significantly elevated (P < 0.01), while serum Zn (13.01 +/- 0.61 mumol/L) was remarkably decreased (P < 0.05). There were no significant changes of serum Cu, Zn and Cu/Zn ratio in early stage cancer patients. It is concluded that the IC method is rapid, accurate, sensitive, relatively simple and could be useful in diagnosing late stage cancers of the digestive tract.