Determination of vitamin D-3 (cholecalciferol) by using voltammetric method

Herein, electrochemical behavior of cholecalciferol on a multiwalled carbon nanotube modified glassy carbon electrode was evaluated by using cyclic voltammetry. Voltammetric determination of cholecalciferol on the prepared modified electrode was carried out using linear sweep voltammetry. A good linearity was obtained with a correlation coefficient of 0,9914 between 5×10-5 – 1×10-3 M. The LOD and LOQ values were calculated as 1,7×10-5 and 5,1×10-5 M, respectively. The response of the proposed electrode was sufficiently repeatable for determining cholecalciferol. Finally, the proposed modified electrode was successfully applied to the determination of cholecalciferol in a commercial oral solution that contains 300.000 I.U cholecalciferol/mL. A simple liquid-liquid extraction technique by using methanol was followed to extract cholecalciferol from the oral liquid. The results obtained with the proposed method were in agreement with cholecalciferol content of the commercial oral solution.