Direct precise determination of Pd, Pt and Rh in spent automobile catalysts solution by high-resolution continuum source graphite furnace atomic absorption spectrometry

This work investigates the analytical possibilities of high-resolution continuum source graphite furnace atomic absorption spectrometry (HR CS GFAAS) for the determination of Pd, N and Rh (PGMs) in spent automobile catalysts without chemical separation. A novel approach for the microwave dissolution with the mixture of HCl and H2O2 (4:1) was developed for the further HR CS GFAAS. It was found that within 20 min at the temperature 210 degrees C of the PGMs quantitatively and simultaneously transferred to solution. It did not show any matrix interferences in determining Pd and Rh, when using HR CS GFAAS for determining the PGMs. When determining N, the matrix effect can be expressly minimized by diluting the sample or applying a corrective model. Limits of quantification (mu g l(-1)) by HR CS GFAAS achieved were 1 (Pd), 2 (Pt), and 0.5 (Rh). Correlation coefficients were 0.9973 (Pd), 0.9995 (N), and 0.9983 (Rh). The relative standards deviation for PGM determination by the developed procedure was not higher than 5% in the concentration range 0.0005-0.5% weight. Moreover, validation of the developed multielement method demonstrated its robustness. The trueness of experimental results was assured by comparison with the atomic emission spectrometry with inductively coupled plasma method.