Sorption of ruthenium(III) and ruthenium(IV) on silica gels chemically modified with mercapto and disulfide groups

Sorption of ruthenium(III) and ruthenium(IV) on silica gels chemically modified with mercaptopropyl and dipropyldisulfide groups was studied. It was shown that the sorption parameters depend on the oxidation state of ruthenium and the nature of the functional group. The maximum recovery was attained from 1-5 M HCl solutions at 95°C and a phase contact time of no more than 20 min. It was shown using EPR and diffuse reflectance spectroscopy that mono- and trans-disubstituted complexes of ruthenium(III) are formed in the sorbent phase during the sorption.