Identification and chromatographic separation of antimony species with α-hydroxy acids

Abstract

The ability of α-hydroxy acids to complex with Sb^III and Sb^V has been established in hydride generation atomic absorption spectrometric determinations of Sb^III and solvent extraction techniques. The nature of this complexation with Sb^V has yet to be rigorously investigated. NMR, electrospray ionisation mass spectrometry and HPLC–ICP-AES methods have been developed to confirm the existence of these complexes in aqueous media and to determine their molecular masses based on a mole-ratio method. It is shown that anion-exchange chromatography can be used to separate mixtures of Sb(OH)_x(L)_n complexes, [L = citric, DL-malic, lactic or (±)-mandelic acid], where n = 6 – x.