The action of certain reagents on the “loosely bound” iron in blood

Abstract
The action of thiolacetic acid, Na pyrophosphate and boiling 5 N HC1, respectively, on oxalated sheep''s blood, was examined. The former reagent attacks Hb iron and is therefore not suitable for the estimation of non-hemoglobin iron. Neither sodium pyrophosphate nor boiling 5 N HC1 was found to attack Hb-iron. Good recoveries of inorganic iron added to blood were given by the former reagent but the apparent non-hemoglobin iron values (0.71-0.97 mgms./100 ml.) were lower than those obtained by the latter reagent (1.22-2.00 mgms./lOO ml.). Fresh blood was found to give a higher non-hemoglobin iron value by the Na pyrophosphate method than blood which had been allowed to stand several days.