ANALYTICAL CHARACTERIZATION OF SUPRAMOLECULAR SPECIES - DETERMINATIONOF RUTHENIUM AND OSMIUM IN DENDRIMERS BY ELECTROTHERMAL ATOMIC-ABSORPTION SPECTROMETRY

Electrothermal atomic absorption spectrometric (ETAAS) methods for det ermining ruthenium and osmium have been developed and applied to the c haracterization of dendritic polynuclear complexes containing both met als. 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 standard s in 1% (v/v) HCl. The absolute detection limits (3s(B)) 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 R u and Os have means which do not differ significantly (P=0.05) from th e expected values. When dendrimers containing 12.2% Ru and 0.9% Os wer e analyzed, the relative standard deviations were, respectively, 7.2% and 11.6% (n=4). Moreover, analytical results for dendrimers containin g both ruthenium and osmium were compared with those independently obt ained by inductively coupled plasma-atomic emission spectrometry (ICP- AES). It is shown that the confidence intervals (95%) overlap to inclu de the ETAAS mean values and the ICP-AES results. (C) 1998 Elsevier Sc ience B.V. All rights reserved.