Macro and Micro Methods for the Determination of Serum Iron and Iron-Binding Capacity

Abstract

Blood serum is incubated with ascorbic acid and hydrochloric acid to liberate protein-bound iron. Proteins are precipitated with trichloroacetic acid in the presence of chloroform. To an aliquot of clear supernatant is added a solution of tripyridyltriazine and sufficient ammonium acetate to adjust the ρH between 4 and 5. Absorbance of the blue-colored complex is measured at 590 m µ . Iron-binding capacity is measured by saturation of serum with ferric iron followed by removal of excess iron with magnesium carbonate. Measurement of total bound iron is completed as above. Macro and micro technics for either determination require 2 ml. and 0.1 ml. of serum, respectively. Reliability of the methods has been established by recovery experiments, replicate analyses, and variation of reagent concentrations and incubation times.