Changes in the molecular mass distribution (MMD) for polymer as a result of adsorption from binary and ternary Solutions have been studied by the exclusion chromatography method. It was found that the affinity of polymer components to a surface has a Crucial influence Oil the changes in MMD of polymers. The diminution of polydispersity in solutions after adsorption was observed for two polymers. In the case of the polar polymer poly(butyl methacrylate) (PBMA) the diminution of polydispersity is Caused mainly by the preferential adsorption of low-molecular-mass fractions, whereas in the case of the nonpolar polymer polystyrene (PS) it is caused by the transition of the high-molecular-mass fractions onto the adsorbent surface. The analysis of experimental results indicates that the quantity of the adsorbent affects the composition of the adsorption layer formed by polymers of different chemical nature. (c) 2004 Published bv Elsevier Inc.