A comparative study of hydrophobicity of octadecyl and alkylamide bonded phases based on methylene selectivityThe conformational dynamics of home-made monomeric and polymeric (octadecyl -C18 and alkylamide -AP) stationary phases have been investigated by analyzing the dependence of retention on the reciprocal temperature for different organic compounds. Theoretical considerations were based on the results of methylene selectivity determination. Two selected PAHs -naphthacene and benzo [a]anthracene, whose structures differ in the position of the ring -were chosen as solutes to study the thermodynamics of retention behavior. Standard enthalpies (DH 0 ) were obtained from the slope of the plots of the capacity factor logarithm (ln k) against the reciprocal temperature (1/T), i. e. van't Hoff plots, in a temperature range from 285 to 315 K. The conformation of the stationary phase (monomeric and polymeric) structure and the length of bonded ligands with their specific functional (N-acylamide) groups had a significant effect on retention.

No abstract

No abstract

No abstract