Flotation-spectrohotometric determination of germanium with phenylfluorone in coal fly ash.

Abstract

A precise and accurate method based on the flotation-spectrophotometry has been developed for the microdetermination of germanium in coal fly ash. The germanium-phenylfluorone complex was floated with cyclohexane at the phase boundary and separated from the excess reagent by removing the aqueous phase. Cyclohexane was a suitable extractant for the separation of germanium tetrachloride from foreign ions. Extractability of germanium was 90.3 ± 0.5 %. Coal fly ash was treated with aqua regia and hydrofluoric acid in a teflon decomposition vessel, and germanium was determined as phenylfluorone complex in a cyclohexane-ethanol medium at 505 nm. The absorbance of the reagent blank was 0.010 ± 0.002. The accuracy of the proposed method was studied by analyzing synthetic samples and NBS 1633 coal fly ash.