DETERMINATION OF VANADIUM, RHODIUM AND PLATINUM IN AUTOMOTIVE CATALYTIC-CONVERTERS USING INDUCTIVELY-COUPLED PLASMA-MASS SPECTROMETRY WITH SPARK ABLATION

A high voltage unidirectional spark source was used as a sampling tool for ICP-MS analysis of automotive catalytic converters, Electrical co nductivity of the samples, required for spark experiments, was provide d hy mixing samples with powdered graphite, Spark discharge parameters , such as peak current and repetition rate, which influence spark samp ling efficiency, were studied and optimized, Prior work involving liqu id nebulization ICP-MS analysis of series of 'palladium-only wavelengt h dispersive X-ray fluorescence secondary standards' was compromised o ffing to spectral interferences arising primarily from polyatomic oxid e species, Additional separation techniques were required in order to separate analyte from matrix elements in cases where interferences cou ld not be resolved, Spark ablation, with its dry plasma, was shown to result in a significant reduction in the formation of polyatomic speci es and simplification of the analytical procedure, Analytical results achieved by ICP-MS with liquid nebulization and with solid sampling ar e compared, Limitations of the spark ablation technique offing to high voltage rf interference on the ICP-MS instrument and spark discharge wander around the sample surface are discussed.