Abstract
A highly sensitive, simple determination of serum Fe and binding capacity is described. FeIII/FeII reacts with chromazurol B and cetyltrimethyl ammonium bromide; the resulting substance is a highly colored ternary complex. Maximal absorbance of the complex occurs at pH 4.6-5.5 at 630 nm. Lambert Beer''s law holds between 0-80 .mu.mol Fe/l. Molar absorptivity is 1.68 .times. 105 l .cntdot. mol-1 .cntdot. cm-1 at 630 nm. Interference by other serum components is negligible even at high concentrations.