Volume 36, Issue 4 (July 1991)
Combined Information from Retardation Factor (Rf) Values and Color Reactions on the Plate Greatly Enhances the Identification Power of Thin-Layer Chromatography in Systematic Toxicological Analysis
A numerical color coding system has been developed to describe the colors of spots obtained after using location reagents in thin-layer chromatography (TLC). This system makes color reactions on the plate amenable to computer handling, so that the retardation factor (Rf) values plus color reactions can be used for identification of unknown substances in toxicological analysis. It is based on a series of four color reactions carried out in sequence on the same plate, and encoding of the observed color is done by means of a wheel of reference colors. The combined information of Rf values plus color reactions resulted in an eightfold increase in identification power in comparison with the information provided by the Rf value alone. Moreover, a single TLC system now provides a three- to four-times higher identification power than a single gas chromatography system like OV-1. The identification power of TLC can be enhanced even further by running two or more systems in parallel.