Ternary complex formation between vanadium(III) salicylic acid and small blood serum bioligands

The complex species formed between vanadium(III)-salicylic acid (H(2)sal) and the small blood serum bioligands: lactic (Hlac), oxalic (H(2)ox), citric (H(3)cit) and phosphoric (H3PO4) acids in aqueous solution were studied by means of electromotive force measurements emf (H) at 25 degrees C and 3.0 mol.dm(-3) KCl as ionic medium. Data analysis using the least-squares program LETAGROP taking into account the hydrolytic products of vanadium(III) and the formed binaries complexes indicated the formation of V(sal)(lac) complexes, [V(sal)(lac)(OH)](-) and [V(sal)(lac)(OH)(2)](2-) in the vanadium(III)-H(2)sal-Hlac system. Species V(sal)(Hox)(+), [V(sal)(ox)](-) were also detected. [V(sal)(ox)(OH)](2-), [V(sal)(2)(ox)](3-) and [V(sal)(ox)(2)](3-) were observed in the vanadium(III)-H(2)sal-H(2)ox system; the complexes V(sal) (H(2)cit), [V(sal)(Hcit)](-), [V(sal)(cit)](2-) and [V(sal)(cit)(OH)](3-) in the vanadium(III)-H(2)sal-H(3)cit system and the species V(sal)(H2PO4), [V(sal)(HPO4)](-) and [V(sal)(PO4)](2-) were detected in the vanadium(III)-H(2)sal-H3PO4 system. The corresponding stability constants were estimated. (C) 2015 Elsevier B.V. All rights reserved.