Indirect polarographic determination of microgram amounts of iron by means of the catalytic oxidation of 5-aminosalicylic acid

Abstract

A sensitive indirect polarographic determination of microgram amounts of iron by means of the catalytic oxidation of 5-aminosalicylic acid with sodium bromate was examined. The most suitable conditions of the pH range, reaction temperature and standing time are 4.8–5.4, 50°C and 1 h respectively. A linear calibration curve is obtained over the range 0.002–0.016 μg ml −1 iron with a relative error of about 3%. Interference by various ions and compounds and the application to the determination of iron in city water and river water are described.