Reduction of Iron by Foods in Artificial Gastric Digestion

In order to carry out studies on the reduction of iron in the gastrointestinal tract a method was necessary for the determination of both ferric and ferrous forms of iron in digestion mixtures.The excellent methods existing for the determination of total iron in foods and biological materials (1) did not meet this requirement.Attempts to use the dipyridyl color reaction to determine ferrous iron in the presence of ferric iron were not successful.Thompson (2) has presented a thiocyanate procedure for total iron in which the colored complex is extracted with isobutanol.By adding the oxidizing agent to one aliquot and omitting it in another and by extracting with a mixture of isobutanol and tertiary butanol a satisfactory modification was developed.EXPERIMESTAL