Determination of germanium in coal ashes by hydride generation and flame atomic-absorption spectrophotometry

Abstract

This paper describes the determination of germanium by atomic-absorption spectrophotometry with direct introduction into a dinitrogen oxide-acetylene flame of the germanium(IV) hydride generated by reducing with sodium tetrahydroborate(III) solution. A comparative study of the sensitivity of the germanium determination has been carried out and a study of interferences from lead(II), arsenic(III) and -(V), iron(II) and -(III), tellurium(IV), selenium(IV), antimony(III), tin(II), tartrates, oxalates and fluorides is described. The sensitivity of the proposed method is 0.012 µg ml^–1 and the detection limit is approximately 100 times better than obtained with silica tube atomisation at a wavelength of 265.14 nm. The method has been applied to the determination of germanium in lignite ashes with an average germanium recovery of 97.65% and a relative standard deviation of 2.87%.