Pyridine-2,3-diol as metal indicator in the chelatometric determination of iron(III) with EDTA

Abstract

Pyridine-2,3-diol can be satisfactorily used as an indicator in the chelatometric determination of iron(III) over the pH range of 1 to 4, the end-point being sharp and distinct. The indicator is effective in the presence of common bivalent metal ions. Interferences from some quadrivalent, tervalent and bivalent metal ions have been prevented by using masking agents, but oxalate and thiocyanate seriously interfere. Borate, tartrate and citrate do not interfere. However, the presence of a large excess of acetate ions must be avoided.