Question

Give principle involved in the limit test for Iron. (Pharmaceutical Inorganic Chemistry)

Answer 1

Limit Test of Iron. Principle: Limit test of Iron is based on the reaction of iron in ammonical solution with thioglycollic acid in presence of citric acid to form iron thioglycolate which is pale pink to deep reddish purple in color. Earlier aamonium thiocyanate reagent was used for the limit test of iron.