An Electrochemical Approach for the Direct Measurement of Buffer Capacity

In dilute buffer solutions, cyclic voltammograms (CVs) of hydroquinone (QH(2)) and quinone (Q) depends on the buffer capacity (beta). The explanation is that the pH changes at the electrode surface cause the electrochemical redox rates of QH(2) and Q rapidly decline and new peaks occur. An electrochemical approach has been developed for measuring beta, which requires the introduction of QH(2) or Q into the solution instead of a strong acid or base. Therefore, the approach has potential for measuring the intracellular beta i without interference from proton transportation. The approach was successfully applied to measure the beta of human saliva. (C) 2014 The Electrochemical Society. All rights reserved.