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A novel approach is developed for the determination of Co and Au dopants in advanced materials based on tin oxide using high-resolution continuum source graphite furnace atomic absorption spectrometry (HR CS GFAAS) with direct slurry sampling. Sodium carboxylmethylcellulose (Na-CMC) is an effective stabilizer for diluted suspensions. Use Na-CMC allows to transfer the analytes into graphite furnace completely and reproducibly. The relative standard deviation obtained by HR CS GFAAS was not higher than 4%. Accuracy was proven by means inductively coupled plasma mass spectrometry (ICP-MS) in solutions after decomposition as a comparative technique. To determine Au and Co in the volume of SnO2, the acid decomposition conditions (HCl, HF) of the samples were suggested by means of an autoclave in a microwave oven.

This paper describes the potential of high-resolution continuum source graphite furnace atomic absorption spectrometry for determination of Pt, Pd and Rh after separation and concentration by original in-house developed heterochain polymer S, N-containing sorbent. The methods of sample preparation of spent ceramic-based autocatalysts were considered, two of which were used: autoclave decomposition in mixture of acids HCl:HNO3 (3:1) and high-temperature melting with K2S2O7. Both methods anyway limit the direct determination of analytes by HR CS GFAAS. Using the first method it is an incomplete digestion of spent autocatalysts samples, since the precipitate is Si, and the rhodium metal dissolves with difficulty and partially passes into solution. In contrast to the first method, the second method allow to completely transfer analytes into solution, however, the background signal produced by the chemical composition of the flux, overlaps the analytical zone. It was found, that Pt, Pd and Rh contained in the spent ceramic automotive catalysts could be effectively separated and concentrated by heterochain polymer S, N-containing sorbent, which has high sorption capacity, selectivity and resistant to dilute acids. The chosen HR CS GFAAS analysis conditions enable us to determine Pt, Pd and Rh with good metrological characteristics. The concentrations of Pt, Pd and Rh in two samples of automobile exhaust catalysts were found in range of 0.00015-0.00050; 0.170-0.189; 0.0180-0.0210wt%, respectively. The relative standard deviation obtained by HR CS GFAAS was not more than 5%. Limits of detection by HR CS GFAAS achieved were 6.2·10(-6)wt% for Pt, 1.8·10(-6)wt% for Pd, and 3.4·10(-6)wt% for Rh. Limits of determination achieved by HR CS GFAAS were 1.1·10(-5)wt% for Pt, 6.9·10(-5)wt% for Pd, and 8.3·10(-5)wt% for Rh. To control the accuracy of PGM in sorption concentrates by HR CS GFAAS method, it was appropriate to conduct an inter-method comparative experiment. The researches on the application of atomic-emission spectroscopy method with inductively coupled plasma as a comparative method were conducted. In addition, the trueness control of the obtained results is confirmed by added-found method.

This work investigates the analytical possibilities of high-resolution continuum source graphite furnace atomic absorption spectrometry (HR CS GFAAS) for the determination of Pd, Pt 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 °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 Pt, the matrix effect can be expressly minimized by diluting the sample or applying a corrective model. Limits of quantification (μg l−1) by HR CS GFAAS achieved were 1 (Pd), 2 (Pt), and 0.5 (Rh). Correlation coefficients were 0.9973 (Pd), 0.9995 (Pt), 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.

A simple, fast and precise method for the electrothermal atomic absorption spectrometry (ETAAS) determination of Au(III), Ag(I), Pd(II) and Pt(IV) from a single aliquot at the level of 10 −4 % in complex samples was developed. The method is based on reducing the interfering effect of Al, Fe, Cu and Ni macrocomponents on determination of Au(III), Ag(I), Pd(II) and Pt(IV) by ETAAS by adjusting the acidic sample solution to pH 9–11 using aqueous ammonia. As a result, 98.4% of Al and 99.7% of Fe precipitated smoothly at room temperature and without additional reagents needed. Furthermore, Au(III), Ag(I), Pd(II) and Pt(IV) did not co-precipitate and remained in the soluble form as ammonia complexes. While soluble ammonia Ni and Cu complexes were also produced, they decomposed in a graphite furnace at 400 °C and did not interfere with ETAAS determination of noble metals. In addition, the benefit of the ETAAS determination of Au(III), Ag(I) in the ammonia complexes is that there were no losses of Ag and Au due to the formation of insoluble AgCl and vaporization of gold and silver chlorides before atomization or incomplete dissociation in the gas phase when conventional sample treatment methods were used The relative standard deviations (R.S.D.) were in the range of 8–10% for determination of Au and Pd in aluminium catalysts, Ag in pure gold samples, and Pt in nickel tailings.