Determination of scandium in coal fly ash and geological materials by graphite furnace atomic absorption spectrometry and inductively coupled plasma atomic emission spectrometry

Abstract

Two procedures for the determination of scandium in coal fly ash and other geological materials have been developed. The first procedure consists in dissolution of the samples with a mixture of nitric, perchloric and hydrofluoric acids in a sealed PTFE vessel followed by determination by graphite furnace atomic absorption spectrometry. In the second procedure, the sample is decomposed by fusion with lithium tetraborate, the melt is dissolved in 5% nitric acid and scandium is determined by inductively coupled plasma atomic emission spectrometry using an argon plasma. The limits of determination are 0.80 and 0.63 µg g^–1, respectively, for the two methods. The scandium concentration in eight coal ash samples obtained by GFAAS and ICP-AES compare well with those determined previously by NAA.