UOP 876-93

This method is for determining platinum by non-differential spectrophotometry in chloroplatinic acid (CPA) solutions that are homogeneous and free of precipitate. Platinum concentrations in the range of 20 to 30 mass-% are typically determined, but the method is not limited to this range. Platinum cannot be determined in the presence of rhenium, iridium and rhodium, which produce colored ions during the color development step and will cause a positive error. However, these elements are not expected to be present in quantities that interfere after the dilution step specified in this method.