SPECIATION OF VANADIUM(IV) AND VANADIUM(V) USING ION-EXCHANGE CHROMATOGRAPHY AND ICP-AES

A speciation method for vanadium(IV) and vanadium(IV) is presented tha t uses a combination of HPLC and ICP-AES. In this method, 1 mM HNO3 so lution and 100 mM HNO3 solution were applied in sequence as eluent. A vanadium(IV) and vanadium(V) mixture was injected into a HPLC anion-ex change column; and vanadium(IV) cation was then eluted by 1 mM HNO3, w hile vanadium(V) oxoacid anion was trapped on the column. After this s eparation, vanadium(V) was eluted as a cation from the column by 100 m M HNO3. Vanadium was detected by ICP-AES. In this separation, about 15 % of vanadium(V) interfered with vanadium(IV), and trace vanadium(IV) interfered with vanadium(V), This interference could be estimated by s imple calculation based on standard observations, and the speciation o f vanadium(IV) and vanadium(V) was performed. The lower determination limit was 1 mu g/mL, which is insufficient to speciate vanadium sample d by conventional sampling methods in a working environment. However, impurity of the other valent vanadium species in a vanadium(V) reagent can be determined by the present method, which should be valuable in precisely assessing the toxicities of vanadium species.