Spectrophotometric determination of vanadium [V] with tannie acid and its application to biological fluids

ABSTRACT

Tannic acid is used in spectrophotometric determination of vanadium [V]. The reagent formed purple-blue color 11 complex with vanadium ion in the pH range 5-6, the wave length of maximum absorbence working wavelength, molar absorptivity, 1 mol-1, Sandell's sensitivity [in ug Cm-2] and standard deviation are 332.2 nm; 8500; 0.028 and 0.52% respectively. The optimum working range is found to be from 0.2 to 10 ppm of vanadium. The stability constant and standard free energy of formation values are reported. The interference of several cations, anions, protein, peptone and some amino acids are investigated. Procedure for the elimination of such interference are suggested. The method has been used successfully for the determination of vanadium in biological fluids