The simple voltammetric analysis of acids using highly boron-doped diamond macroelectrodes and microelectrodes

In this paper, the simplest methods developed so far for the analyses of pH and acid concentrations in acid solution are described, using a technique based on highly boron-doped diamond (BDD) electrodes. These simple analyses take advantage of a very attractive electrochemical property of BDD electrodes, i.e., a very wide potential window. It transpires that the value of the current generated by hydrogen evolution during the reduction of an acid when measured by linear sweep voltammetry (LSV) measurements accurately reflects the proton concentration (pH) when using a BDD macroelectrodes (hereafter designated as BDD-M), whereas accurate measurements are impossible when using conventional electrode materials such as glassy carbon, metal etc because of their narrow potential windows. Furthermore, the measurements of weak acid concentrations [HA] were also possible by using both the pH value (obtained by BDD-M) and the limiting current value obtained by using BDD microelectrodes (hereafter designated as BDD-m).