FIA determination of Cr~(III) in tap water with chemiluminescence detection

摘要

Cr~(III) has been determined by measuring the light emitted as a result of the Cr~(III)-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 Cr~(III) 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 Cr~(III) in tap water; the Cr~(III) concentration varied between 10 and 20 μg l~(-1) with a typical coefficient of variation of 2% (n = 5).