ICP-MS Determination of Noble Metal Elements in Car-Use Ceramic Catalytic Converters

The sample of car-use ceramic catalytic converter was digested with HF and HNO3-HCl (3+4) solution, and the undissolved Al2O3 was reacted with NaOH to form mataaluminate, which was dissolved with HNO3-HCl (1+3) solution. The contents of 3 precious metal elements, i.e., Pt, Pd and Rh in the sample solution were determined by ICP-MS. Appropriate isotopes of the elements determined and correction equations were selected to overcome the mass spectrometric interferences, and dilution of sample solution were adopted to overcome the non-mass spectrometric interferences. Values of detection limit (3s) for the 3 elements were found in the range of 0.01-0.14 μg·L-1. The proposed method was applied in the analysis of substantial sample, giving values of recovery and RSD′s (n=6) in the ranges of 93.2%-98.0% and 0.63%-1.5% respectively.