On the determination of platinum group elements in environmental materials by inductively coupled plasma mass spectrometry and microwave digestion

The interferences from Cd, Cu, Hf, Pb, Sr, Zn, Zr and Y on the inductively coupled plasma quadrupole mass spectrometry (ICP-MS) determination of Pt, Pd, Rh, Ru and Ir in geological (Pt-ore SARM-7, abundance range for platinum metals 0.07-3.74 mug/g) and environmental samples (sediment JSd-2 abundance range for Pt and Pd 0.0167-0.021 mug/g; road dust and plant sample) are evaluated using model solutions, real samples and comparison to inductively coupled plasma atomic emission spectrometry (ICP-AES) results. Pt, Rh, Ru and It can be determined usually after introduction of corrections for the interference in all investigated materials though in sediments the direct determination of Pt might be a problem depending on the actual Hf concentrations. The direct determination of Pd (after microwave-assisted acid digestion) is possible in ores using all investigated isotopes (Pd-105, Pd-106, Pd-108), in plants using Pd-108 and correction for the interferences of Zr, Mo and Cd, and not possible in sediments and road dust. Therefore, we developed a procedure for isolation of Pd using its diethyl-dithio-carabamate (DDTC) complex. The detection limits for Pt, Pd and Ir are 0.015 ng/g, and for Ru and Rh 0.03 ng/g. (C) 2003 Elsevier B.V. All rights reserved.