Adsorbent type:

Various adsorbent types exhibit different selectivities towards different types of compound. Polar adsorbents such as metal oxides, magnesium silicate etc. selectively adsorbs unsaturated, aromatics and polar molecules such as alcohols, amines and acids. Polar adsorbents may be further sub-divided as acidic, basic or neutral, according to the pH of the surface. Silica, magnesium silicate is acidic and therefore, they chemisorb bases. The alumina surface holds both acidic and basic sites. The Non-polar adsorbents like as graphitized carbon that is a strong adsorbent and kieselguhr which is a weak adsorbent show no selectivity for the adsorption of polar molecules.