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 495 nm, respectively. The carrier solution (0.1 M sodium chloride) and buffer solution (pH 7.5) containing 8×10−3M kojic acid were each pumped at 1.5 ml min−1. The length of the reaction coil was 1 m. The present method allows the determination of 1–10 µg ml−1 of gold (III) based on 100 µl injection volume. The relative standard deviation of 1.2% (n=9) was obtained at 3 µg ml−1 of gold(III). The sample throughput was about 20 h−l. Palladium does not interfere with up to 50-fold amounts under masking with nitrilotriacetic acid. © 1995, The Japan Society for Analytical Chemistry. All rights reserved.