Determination of Trace Amounts of Indium by Graphite-Furnace Atomic Absorption Spectrometry after Preconcentration as the Acetylacetonato Complex on Activated Carbon

Abstract

A rapid and simple preconcentration method by selective adsorption using activated carbon as an adsorbent and acetylacetone as a complexing agent is described for the determination of trace amounts of indium by graphite-furnace atomic absorption spectrometry. The indium-acetylacetonato complex is easily adsorbed onto activated carbon at pH 6.0-8.0. After the activated carbon phase, the adsorbing indium-acetylacetonato complex is separated and dispersed in 5ml of a 2%(v/v) glycerine solution containing 700μg of palladium. The resulting suspension of activated carbon is introduced directly into the graphite-furnace atomizer. The detection limit was 0.025μg/l(s/n=3), and the relative standard deviation was 4.0-5.0% at 1.0μgIn/100ml (n=10). This method was applied to the determination of indium in water samples and proved to be a useful technique for the preconcentration of trace amounts of indium in water samples.