Solvent-extraction spectrophotometric determination of tungsten and molybdenum in single crystals of synthetic corundum and lithium niobate

Methods of extraction-spectrophotometric determination of tungsten and molybdenum in single crystals of synthetic corundum and lithium niobate, based on the formation of three-component complexes with potassium thiocyanate in the presence of cetyltrimethylammonium bromide are developed. Prior to extraction tungsten and molybdenum were reduced up to +5 oxidation degree. Conditions for formation and extraction of complexes depending on medium pH and reagent concentration are studied. Relative standard deviation when determining from 5x10-4 to 1x10-2 % of tungsten and molybdenum does not exceed 0.08 (n=10)