General equations to model cyclic voltammetric experiments at a large ITIES are presented for multiple ion transfer. A method of integration of the mass balance equations is exposed and further applied to the case of an amphoteric molecule. This approach is based on the definition of total concentrations and on a Nicholson-Shain integration of the convolution integrals. This numerical method is validated by comparison with simulations performed for simple and facilitated ion transfer reactions and by comparison with experimental results.