Use of an Anion-Exchange Column to Determine Serum Iron-Binding Capacity

Abstract

Abstract A rapid procedure is described for determining total iron-binding capacity (TIBC) by use of a small, disposable resin column. Serum is saturated with excess ferric citrate, and iron not bound to protein is then removed by passing the mixture through the column of anion-exchanger. Transferrin-bound iron in the effluent, the TIBC, is determined colorimetrically (AutoAnalyzer), with 2,4,6-tripyridyl-1,3,5-triazine as color reagent. The percentage saturation with iron may be obtained from colorimetric measurement of original serum iron and the TIBC, or by radioactive counting if 59Fe is incorporated in the ferric citrate used to saturate the serum. Our method is compared with the MgCO3 precipitation technique for the removal of excess iron after saturation and to an ultrafiltration technique in which protein-bound iron is retained by a membrane and the filtrate analyzed for unbound iron, thus obviating absorbents in the determination of TIBC. Results from the resin-column and ultrafiltration procedures correlated well, whereas those from the MgCO3 method were consistently lower and more erratic.