Determination of indium and tellurium in fifty nine geological reference materials by solvent extraction and graphite furnace atomic absorption spectrometry

The indium (In) and tellurium (Te) contents of fifty nine geological refere nce materials, issued by several reference material producers (USGS, CRPG, ANRT, GIT-IWG and GSJ) have been determined by graphite furnace atomic abso rption spectrometry, after aqua regia and HF digestion, and extraction of i odide complexes with trioctylmethylammonium (TOMA) - metyl isobutyl ketone (MIBK). Although the interferences from most elements can be minimised by t he addition of palladium solution as the matrix modifier, large concentrati ons of Bi, Cu, P6b or Sn suppress the absorbance of In and/or Te. Samples f or analysis were therefore restricted to those in which the concentrations of these interfering elements did not cause a significant interference. The limit of detection was 0.2 ng g(-1) In and Te for 1 g test portions. The a greement between the reported results and published data is satisfactory.