Riboflavin (Vitamin B2) Assay by Adsorptive Cathodic Stripping Voltammetry (Adcsv) at the Hanging Mercury Drop Electrode (HMDE)

摘要

In this study the interactions of Riboflavin (Vitamin B2) with a mercury surface are investigated. Firstly, by using CyclicudVoltammetry, it is demonstrated that Riboflavin can be efficiently accumulated, by adsorption from buffered solutionsudcontaining an excess of NaClO4, onto the mercury drop of a HMDE. Secondly, it is shown that the adsorbed Riboflavinudcan be reduced through an electrochemical reaction whose stoichiometry is extricated by confronting simulated withudexperimental CV voltammograms acquired in a range of pH between about four and nine. Finally, the cathodic current,udsustained by the surface reduction of Riboflavin, is exploited for assaying Riboflavin via Differential Pulse AdsorptionudCathodic Stripping Voltammetry (DP AdCSV) within the frame of the standard additions calibration procedure.udBy applying the suggested DP AdCSV procedure with standard voltammetric equipment, typical DP settings andudpre-electrolysis time of about 10 s, a linear response is maintained if Riboflavin concentration in the electrolysed solutionuddoes not exceed about 2 mg/l. On the other side, a limit of detection (expressed as the concentration of Riboflavin in theudelectrolysed solution) of 7 μg/l has been achieved with a pre-electrolysis time of 68 s.