Thin-layer chromatography correlation with HPLC

The cycloalkylcarbamates do not absorb UV light above 220 nm and therefore can be used as the CSPs for thin-layer chromatography (TLC).191 The TLC chromatogram was readily detected by UV radiation at 254 nm and showed the resolution of racemates into each enantiomer. The TLC results can be compared with those obtained by HPLC with the same CSP. The a values in HPLC are slightly larger than those in TLC, although a good correlation is observed between these a values. The cycloalkylcarbamates can be very useful CSPs for TLC as well as for HPLC resolution. 

Chromatographic Parameter-Relationships Correlations between Kov/ and various chromatographic parameters (CGP), such as HPLC retention time and thin-layer chromatography (TLC) capacity factors, allow the experimental estimation of Kow [19]. Usually, the CGP-A ow correlation is evaluated for a calibration set of compounds with accurately known K0w values. The Kow of a new compound can then be estimated by determining its CGP under the same experimental conditions as those used for the calibration set. 

A number of other surrogate procedures have been developed. These include the use of reverse-phase thin-layer chromatography (TLC) (Bruggeman et al. 1982 Renberg et al. 1985) to measure relative mobilities (Rm) or reverse-phase high-performance liquid chromatography (HPLC) to measure capacity factors (Veith et al. 1979b). These values are then correlated with experimentally established Pow values for standard compounds, and the correlation is then used to calculate values of Pow for the unknown compounds. 

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