Iodimetric determination of iodate, bromate, hypochlorite, ascorbic acid and thiourea using flow injection amperometry

Abstract

Iodate, bromate and hypochlorite were determined as iodine by flow injection amperometry at a platinum or glassy carbon electrode by injecting them into an eluent 0.20 M in hydrochloric acid and 0.024 M in potassium iodide or an eluent 2 M in sulphuric acid and 0.12 M in potassium iodide. The rectilinearity range is from 10^–3 to 10^–7 M. Organic compounds that can be oxidised or iodinated by iodine were determined on-line by injecting them in acidic solution into an iodate-iodide eluent and observing the decrease in the iodine signal. The determination was also performed by injecting a pre-reacted solution of iodine and the organic compound and monitoring the excess of iodine.