This method is for determining platinum in spent catalysts or catalyst residues at concentrations from approximately 0.05 to 1.0 mass-% by spectrophotometry. The method is applicable to catalysts that may range from gamma- or alpha-alumina to pure silica, aluminum silicates, corderite, mullite and cristobalite, etc. Catalyst residues containing high concentrations of barium sulfate cannot be analyzed.
