[en] A model of a multiple ion plasma is considered in which the system may contain many atomic species, each with an arbitrary number of charge states, but in which the atomic species are disparate in mass. Using this approximation is calculated in analytic form, the multispecies Spitzer function, from which there follow tractable expressions for the Ware fluxes and bootstrap current in a tokamak. In the collisional regime of a tokamak plasma, we obtain simple analytic results are obtained for the radial transport coefficients. These results give rise to an efficient method of solving the ensuing diffusion equations