FIA determination of Criii in tap water with chemiluminescence detection

Abstract

CrIII has been determined by measuring the light emitted as a result of the CrIII-catalysed reaction between luminol and hydrogen peroxide. Increase in the sensitivity of the determination was achieved by introducing bromide into the reaction mixture while the selectivity was improved by the addition of EDTA. All the operations were performed on-line in an automated FIA system. The calibration curve for CrIII was linear in the range 0–500 µg l^–1 and the limit of detection was 0.5 µg l^–1. The method was applied to the determination of CrIII in tap water; the CrIII concentration varied between 10 and 20 µg l^–1 with a typical coefficient of variation of 2% (n = 5).