Flow-through dialysis of zinc(II) from model and human sera

Dialysis of zinc(II) through cellulose-acetate membranes was studied in a flow-through dialyzer. The metal ion concentration was determined with differential pulse anodic stripping voltammetry in a flow-through cell with a detection limit of 10(-9) M zinc(II). The concentration of zinc(II) in the dialysate decreased by x750 when albumin was added in an excess corresponding to the physiological concentrations. Addition of amino acids in physiological concentrations had little or no effect on the transfer of zinc(II) through the membrane. Albumin solutions and a model serum containing inorganic salts, amino acids, lipids, and carbohydrates were compared with pooled serum. Zinc(II) was transferred faster from the latter at equal concentrations of exchangeable total zinc. Predialysis of the pooled serum decreased the zinc(II) transferring capability indicating some unknown mode of transport from the untreated serum.