Determination of platinum,palladium,rhodium in motor metal catalyst by inductively coupled plasma mass spectrometry

After motor metal catalyst was dissolved with hydrochloric acid and filtered,the residue was treated by ashing and grinding.The sample was fused by alkali,and co-precipitated with tellurium for separation and enrichment of Pt,Pd and Rh.Consequently,a determination method of Pt,Pd and Rh by inductively coupled plasma mass spectrometry(ICP-MS)was established.The dissolution conditions,including sodium peroxide dosage,fusion temperature,hydrochloric acid volume,and tellurium co-precipitation time,were investigated by orthogonal test L9(34).The possible mass spectral interference was eliminated by selecting the appropriate determination isotope;and the influence of signal drift was canceled with In as internal standard element for Pd and Rh and Tl as internal standard element for Pt.The method was applied to the determination of Pt,Pd and Rh in the industrial reference material KTA038of motor metal catalyst.The results were consistent with the certified values,and the relative standard deviations were between 3.1%-4.9%.The recoveries were in the range of 98%-102%.