High performance liquid chromatography (HPLC) was used to determine the association rate constants of antigen-antibody reactions at the solid-liquid interface. The adsorption of human serum albumin (HSA) on monoclonal and polyclonal anti-HSA antibodies immobilized on a HPLC silica support was studied by frontal analysis, The theoretical model assumes irreversible adsorption during the time scale of the experiment, The shape of the breakthrough curves reveals the presence of several kinetic adsorption steps : the model fits well the first part of the elution profile. Frontal analysis gives the apparent adsorption rate constant, which includes the mass transfer in the stagnant fluid phase, This effect can be accounted for by carrying out studies as a function of flow rate on columns packed with adsorbents having various densities of immobilized antibody, Within experimental error, the effective rate constant for the irreversible adsorption process is in good agreement with previous experiments performed by saturating the column with repeated pulse injections.