Reaction of gallocyanine methyl ester with uranyl ions

Abstract

The reaction of gallocyanine methyl ester with uranyl ions was studied spectrophotometrically in slightly acid or neutral solutions in 40% (m/m) ethanol. A violet complex of UO2L2 is formed at pH > 5. The conditional stability constants of the complex in the pH 6 - 7.4 range and the equilibrium constants of the coordination reaction were derived from the concentration curves and continuous variations curves. The optimum conditions were sought for the spectrophotometric determination of uranium based on the occurrence of the UO2L2 complex. The relative standard deviation obtained for a uranium concentration of 106 μg l-1 was sr = 2.13%.