DETERMINATION OF BISMUTH IN GEOLOGICAL-MATERIALS BY FLAME ATOMIC-ABSORPTION SPECTROMETRY USING A SELECTIVE EXTRACTION TECHNIQUE

An investigation has been carried out to establish a rapid method for the determination of bismuth in geological samples (especially geochemical exploration samples) by flame atomic absorption spectrometry using a boosted-output hollow cathode lamp. Bismuth iodide is first extracted into isobutyl methyl ketone and then bismuth is stripped into an aqueous ethylenediaminetetraacetic acid solution for nebulization into an air-acetylene flame. In order to determine the accuracy of the method, geochemical exploration reference samples issued by the US Geological Survey and other international reference samples were analysed using the proposed method and the results obtained were compared with those obtained using other atomic absorption spectrometric procedures. The proposed method can be applied to a variety of geological samples for the determination of bismuth at levels as low as 0.4 ppm.