General ion recruiting procedure for pH-based calculations

In this paper, a simple procedure is developed to numerically evaluate the total equivalents introduced by any buffer component in a solution. The same procedure calculates the corresponding derivative with respect to the hydrogen ion. The procedure is useful for generalising the pH calculation for any pH-dependent model with reduction of the model stiffness. It is also found to be useful to calculate total alkalinity and to simulate titration experiments for a solution with known buffer composition.