[en] We present here a new validation approach wherein analytical charge-form speciation data obtained with resin columns verifies the relative quantities of anionic vs cationic plus neutral species calculated via the MINTEQ equilibrium thermodynamic geochemical model (Felmy and Jenne, 1983). We thereby generally validate thermodynamic calculations of charge-form speciation, identify instances of discordant results which could suggest a deficiency in the thermodynamic model or analytical technique, and demonstrate the necessity of using highly competent geochemical models. 18 references, 2 tables