Unconventional TLC systems in lipophilicity determination: A review

ABSTRACT

This review focuses on four unusual thin-layer chromatography (TLC) approaches for the determination of lipophilicity: (1) the use of medium-polar stationary phases: CN, NH₂, and DIOL instead of RP plates, together with water-based mobile phase; (2) the use of silica gel in a typical normal-phase manner and treating extrapolated retention indices as the “reversed lipophilicity”; (3) the use of oil impregnated silica gel in the reversed-phase manner; and (4) the use of salting-out mobile phases. The chromatographic indices obtained in these systems are numerously reported as well correlated with lipophilicity and they are an interesting alternative to classical RP systems approaches.

GRAPHICAL ABSTRACT

KEYWORDS:

• Impregnated plates
• lipophilicity
• polar stationary phases
• QSRR
• salting-out chromatography
• thin-layer chromatography