Vanadium detoxification: On the interaction of oxovanadium(IV) and other vanadium species with 2,3-dimercapto-1-propanesulfonate

The interaction of the VO2+ cation with the sodium salt of 2,3-dimercapto-1-propanesulfonic acid (DMPS) was investigated by electron absorption spectroscopy in aqueous solution, in the pH range between 4 and 12. The spectral behavior points to the generation of a [VO(DMPS)2]4− complex in which the oxocation interacts with two pairs of deprotonated –SH groups of the ligand. By spectrophotometric monitoring it was found that DMPS rapidly reduces vanadates(V) to VO2+ which may be chelated by an excess of the acid. DMPS produces also the slow reduction of a V2O5 suspension at pH 7.1. The results of this study suggest that DMPS may be a potentially useful detoxification agent for vanadium.