ICP-MS Determination of Pt, Pd and Rh in Catalysts for Auto-exhaust-gas Purifier

Sample of catalysts for auto-exhaust-gas purifier was fused with Na2O2, and the melt was dissolved in hot water and acidified with HCl. An aliquot of the sample solution was taken for ICP-MS determination of Pt, Pd and Rh. 111Cd and 203Tl were used as internal standards. Values of detection limit (3s) of Pt, Pd and Rh found were 0.048, 0.056, 0.019 μg·g-1 respectively. The proposed method was used in the analysis of 5 catalyst samples, the results obtained were in conformity with those obtained by photometry. Values of recovery and RSD′s (n=12) found were 100.0% and 1.3% for Pt, 100.0% and 1.0% for Pd, 99.8% and 1.6% for Rh respectively.