Effect of TLC support characteristics and coating on the lipophilicity determination of phenols and aniline derivatives.
The lipophilicities of 18 ring-substituted phenol and aniline derivatives are determined on alumina and silica thin-layer chromatographic supports impregnated with 2.5 and 10% (v/v) paraffin oil in n-hexane using a mixture of water-methanol as the mobile phases. The effect of calculated physicochemical parameters and chromatographic conditions on the retention is elucidated by stepwise regression analyis. It is established that the degree of impregnation exerts a greater impact on the retention than the character of the support. Not only the calculated lipophilicity but also various sterical and polarity parameters significantly influence the retention, indicating the involvement of factors other than hydrophobic forces in the retention mechanism.
Cserháti
Tibor
T
Institute of Chemistry, Chemical Research Center, Hungarian Academy of Sciences, PO Box 17, 1525 Budapest, Hungary.
Forgács
Esther
E