Liquid-liquid extraction combined with atomic-absorption spectrometry for determination of copper in waters, foods and analytical reagents using 1,2-naphthoquinone thiosemicarbazone

Abstract

An atomic-absorption spectrometric method for the determination of trace amounts of copper in solution with 1,2-naphthoquinone thiosemicarbazone is described. This compound reacts with copper in a weakly acidic medium to produce a complex that can be extracted into isobutyl methyl ketone. The atomic absorption of the organic phase is measured at 324.8 nm. The sensitivity of the method is 0.6 ng ml^–1 for 1% absorption in aqueous solution and the presence of several milligrams of 55 foreign ions is tolerated. The method has been applied successfully to the analysis of waters, foods and analytical reagents.