DETERMINATION OF PLATINUM, PALLADIUM, RHODIUM AND TITANIUM IN AUTOMOTIVE CATALYTIC-CONVERTERS USING INDUCTIVELY-COUPLED PLASMA-MASS SPECTROMETRY WITH LIQUID NEBULIZATION

ICP-RLS was used for the determination of Pt, Pd, Rh and Ti in automot ive catalytic converters, A microwave digestion procedure employing a mixture of H2O, HF, HCl and HNO3 was studied and compared with a proce dure using a mixture of H2SO(4), H3PO4 and aqua regia. The use of the latter results in significant losses of Pt and Ti, The influence of sa mple size on the recoveries of Pt, Rh, Ti and some REEs is discussed, It is shown that a sample amount larger than 0.12 g results in incompl ete recoveries of REEs with no significant loss of the other elements, Instrument calibration using the standard addition method and matrix matching are discussed, It is shown that close matrix matching using c ordierite, the substrate, with a washcoat, the catalyst support, provi des spectral interference correction for polyatomic oxide species, The results obtained are in good agreement with those obtained by wavelen gth-dispersive X-ray fluorescence analysis.