Erratic Data in Thin Layer Chromatography Due to Anomalous Behavior of Correction Standards

Correction of crude thin layer chromatographic data usually enables a reliable comparison with reference data bases. However, when the correction standards are not spotted in the right positions, the calculation may produce false results if anomalous migration occurs. This was observed in the case of acidic and neutral drugs developed in the chloroform-methanol (9:1) system. In t roduct ion Correction of retention data in thin layer chromatography (TLC) is a basic requirement in systematic toxicological analysis. Existing methods of correction (1-5) enable an efficient use of reference data bases of compilations published by other toxicol-ogists. When the correction of raw retention data is made with standard substances, one condition must be fulfilled: the stand-ards must show comparable r tention behavior in relation to th