Comparison of Microwave-Assisted Digestion Methods and Selection of Internal Standards for the Determination of Rh, Pd and Pt in Dust Samples by ICP-MS

Different temperature-pressure controlled microwave-assisted digestion methods were compared for the digestion of dust samples prior to the determination of rhodium and platinum by inductively coupled plasma mass spectrometry (ICP-MS). The results obtained for platinum and rhodium in the digested reference material (BCR-723, road dust) were generally in good agreement with the certified values. However, the determination of matrix elements (Zn, Rb, Sr, Y, Hf and Pb) showed clear differences between the digestion methods. In addition, different internal standards were compared in the determination rhodium, palladium and platinum by ICP-MS. According to the results, even serious non-spectral interferences can be corrected by choosing a suitable internal standard or combination of internal standards.