SPECTROPHOTOMETRIC STUDIES OF 4-(2-HYDROXY-4-SUBSTITUTED-AZOBENZENE)-2 METHYL-QUINOLINES AS REAGENTS FOR THE DETERMINATION OF SILVER

The spectroscopic behaviour of some quinoline azo dyes has been studie d. A simple, rapid, accurate, and sensitive method for the spectrophot ometric microdetermination of Ag(I) ions using the title compounds is given. The conditions for the formation of the coloured complexes are obeyed up to 26 mu g . ml(-1); the optimum concentration range for app lication of the Ringbom method is 2.5-23 mu g . ml(-1). The molar abso rptivity and the Sandell sensitivity have also been calculated. The me thod proved to be successful in determining Ag+ in photography fixing solutions. The results agreed satisfactorily with those obtained using standard atomic absorption spectroscopy.