engleski

Vanadium(IV) and vanadium(V) complexation with succinic acid by affinity capillary electrophoresis

The complexation of different vanadium species (+IV and +V) with succinic acid was examined by affinity capillary electrophoresis (ACE) in aqueous acid solutions at different pH values (1.5, 2.0 and 2.5). In this study, succinic acid is chosen as a complexing agent for V(IV) and V(V) species as it can be used as a simple model of structurally more complex NOM. ACE is based on the change in the electrophoretic mobility of detected species due to the interaction with other species present in the electrolyte. The injected sample contains a fixed amount of V species. A set of runs is performed using (H, Na)ClO4 mixtures at constant pH and ionic strength (0, 1 M), while the background electrolyte (BGE) contains varying amounts of succinic acid. The change in electrophoretic mobility with the increase of ligand concentration in the BGE is used to assess the speciation and equilibrium constants. Obtained data allow us to unravel the formation of protonated V(IV) and V(V) complex species and calculate their stability constant values.

vanadium ; capillary electrophoresis ; succinic acid ; complex stability

nije evidentirano