Adsorption - accumulation of molecules or ions on the surface of any body. Examples of absorption : the absorption of gases and substances from solutions charcoal, clay. If absorbed substance (adsorbtive) chemically reacts with absorber (adsorbent), the process is called chemisorption. Adsorption is used in gas masks (see) for air purification from harmful gases for the analysis of complex mixtures (see Chromatography), and in the treatment of some diseases of the gastrointestinal tract (see Activated carbon). Cm. also Absorption.