Now, it becomes possible to compensate for the asymmetry due to the H + or OH -contributions by changing the concentration of either species in order to improve the buffer index in the target pH-area, which is obtained by converging towards a set of concentrations C 1 and C 2 such that the single triple root is restored. In practice, here, we reached that goal by setting the value of C 1 and then optimizing C 2 .