Macro and micro methods for the determination of serum iron and iron-binding capacity.

Blood serum is incubated with ascorbic acid and hydrochloric acid to liberate protein-bound iron. Proteinsare 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 pH between 4 and 5. Absorbance of the blue-colored complex is measured at 590 m. Iron-binding capacity is measured by saturation of serum with ferric iron followed by removalof excessiron 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 concentrationsand incubation times.