A commercial electrochemical method evaluated for measurement of iron status

I evaluated a commercial electrochemical method (Environmental Science Associates), based on potentiostatic coulometry, for determining iron and total iron-binding capacity (TIBC). The method requires 25 and 100 microL of serum, respectively, for these measurements. Serum iron concentrations so determined in 99 normal volunteers satisfactorily correlated with those determined by the Iron Panel Method (Br J Haematol 1978;38:291-4), although the former required correction for lower-than-expected values. The coulometric TIBC results, on the other hand, correlated poorly with those by the Iron Panel Method. However, when the samples for TIBC were prepared according to the Iron Panel Method, by using the magnesium carbonate technique, and then read in the coulometer, there was satisfactory correlation between TIBC values as determined by the two methods. Variability and analytical recovery of the electrochemical method are satisfactory, and the method should be useful for measurement of serum iron when only relatively small volumes of blood are available.