Determination of platinum, palladium, osmium, indium, rhodium and gold as chloro complexes by capillary zone electrophoresis

摘要

The influence of pH, concentration of chloride in the background electrolyte, temperature, cetyltrimetylammonium, and other factors on the capillary zone electrophoresis of platinum group metals has been investigated. A high efficiency of the separation of Os(IV), Pt(IV), Ir(lll), Pd(II), Au(III), Rh(III) and reduction of the analysis time to 5-6 min under the optimal conditions was achieved at elevated temperature. The possibility of simultaneous determination of Pt(II) and Pt(IV), or Os(IV) and Os(III) has also been demonstrated. The stability constants of chloro complexes of Pd(II) l:n (Pd: Cl). n=2, 3, 4 and their mobilities were determined at ambient and elevated temperatures. In case of Pd(II) it was shown that the increase of the efficiency with temperature can be explained by changes of the stability constants of chloro complexes. The determination of platinum group metals in some real samples was made and compared to that of inductively coupled plasma atomic emission spectrometry. Detection limits achieved were in the range 0.1-0.6 ppm.