Flow-injection spectrofluorometric determination of gold with kojic acid

Abstract

A flow-injection spectrofluorometric method was devised for the determination of gold (III) based on the fluorescent oxidized product of kojic acid. The maximum wavelengths of the excitation and emission spectra of the oxidized product are 375 and 495nm, respectively. The carrier solution (0.1M sodium chloride) and buffer solution (pH 7.5) containing 8×10^-3 M kojic acid were each pumped at 1.5ml min^-1. The length of the reaction coil was 1m. The present method allows the determination of 110μg ml^-1 of gold (III) based on 100μl injection volume. The relative standard deviation of 1.2% (n = 9) was obtained at 3μg ml^-1 of gold ( III ). The sample throughput was about 20h^-1. Palladium does not interfere with up to 50-fold amounts under masking with nitrilotriacetic acid.