A new procedure for determining copper in igneous rock and alloys

The influence of cationic surfactants, cetylpyridinium chloride (CPC), cetylpyridinium bromide (CPB), and cetyltrimethylammonium bromide (CTMAB), on the complexation of copper(II) with thenoyl-(2-oxopropyl)-N-(2-sulfo-4-nitro-5-oxyphenyl) azomethine (R) has been investigated. It has been found that monoligand compounds are formed at pH 4, while at pH 3 the formation of mixed-ligand compounds is observed. The detection limit for copper decreases and the stability constants of the complexes increase in the row Cu-R-CPC > Cu-R-CPB > Cu-R-CTMAB, with AN increase in the stability of the associates (Rh-CPC > R-CPB > R-CTMAB) in the complexation reaction. The ratio of components in monoligand (1: 1) and mixed-ligand (1: 1: 1) compounds has been determined. The limits of obedience to the Beer law have been found. A procedure has been developed for the photometric determination of copper in igneous rock and alloys.