LAUSR

Adsorption mechanism of caffeine, quercetin and phenol as test substances in various chromatographic systems have been analyzed. The investigations were conducted using three different chromatographic columns packed with polar bonded stationary phases, i.e. amide, amine and zwitterionic. Methanol - water and acetonitrile - water systems with different organic solvent contents have been used as mobile phases. On the basis of adsorption isotherms obtained for the tested systems Scatchard plots and adsorption energy distributions have been determined. The most likely retention mechanisms have been discussed. The results of investigations indicate that: (i) the surfaces of tested adsorbents are energetically heterogeneous, (ii) the main role in sorption mechanism play low energy sites. This article is protected by copyright. All rights reserved.