Characterization of Cr-Curcumin Complex by Differential Pulse Voltammetry and UV-Vis Spectrophotometry

Differential Pulse Voltammetry (DPV) and UV-Vis techniques were used in characterizing the complexation of chromium with curcumin. It was observed that chromium complexed with curcumin in a 1 : 3 ratio. The experimental values that were used to calculate this ratio were independently determined by the two techniques used. The values obtained from each technique agree with each other reasonably well, within limits of experimental error. The stability constant or formation constant, Kf , of the complex, 1.58×1010 , was determined using the Lingane equation and Gibb’s free energy of formation was calculated as −58.18 kJ.