Analytical characterization of supramolecular species – determination of ruthenium and osmium in dendrimers by electrothermal atomic absorption spectrometry Original Research Article

Electrothermal atomic absorption spectrometric (ETAAS) methods for determining ruthenium and osmium have been developed and applied to the characterization of dendritic polynuclear complexes containing both metals. While in the determination of osmium the interference due to the ruthenium makes it necessary to use a standard addition procedure, the determination of ruthenium can be performed directly against standards in 1% (v/v) HCl. The absolute detection limits (3sB) are 65 pg for ruthenium and 3 ng for osmium. The method was preliminarily tested by analyzing chemicals of known composition. Results obtained for both Ru and Os have means which do not differ significantly (P=0.05) from the expected values. When dendrimers containing 12.2% Ru and 0.9% Os were analyzed, the relative standard deviations were, respectively, 7.2% and 11.6% (n=4). Moreover, analytical results for dendrimers containing both ruthenium and osmium were compared with those independently obtained by inductively coupled plasma–atomic emission spectrometry (ICP–AES). It is shown that the confidence intervals (95%) overlap to include the ETAAS mean values and the ICP–AES results.