Rule for use of the fuchsine dyes as the visualizing reagents in TLC of organic compounds

MICROCHEMICAL

JOURNAL

16, 480-482

( 197 1)

Rule for Use of the Fuchsine Dyes as the Visualizing Reagents in TLC of ‘Organic Compounds ZBIGNIEW

GREGOROWICZ AND JOSEF SLIWIOK

Department of Analytical and General Chemistry, Silesian Technical University, Gliwice, Poland; and Department of Organic Chemistry, Silesian University, Katowice, Poland Received April 30, 1971

The problem of using the proper visualizing reagent in paper and thin-layer chromatography has high, analytical importance. The visualizing reagent which is to be applied in chromatographical analysis, ought to possessthe following properties: a. to visualize microgram amounts of analyzed substances; b. to react with the developed substances and to give possibly numerous color effects; c. to give satisfactory contrast between chromatographical spots and ground; d. to give chromatographical spots of high firmness; e. to provide quantitative determination of the developed substances. The reagents in use do not always correspond to the above characteristics. Generally, the visualizing reagents may be divided into two groups: of the preserving and destructive compounds. The purpose of this work is to show the results of our investigations devoted to the tracing of some regularities in the application of the fuchsine dyes as the visualizing reagents in TLC of organic compounds. DISCUSSION

The analyzed substances were separated by means of adsorption TLC, the particular conditions being described in our previous papers (I,2). We investigated substances of hydrophobic, faintly hydrophobic, and hydrophilic properties, all of them being visualized by means of new fuchsine. From the group of hydrophobic substances, the following compounds 480

TLC

OF ORGANIC!

481

COMPOUNDS

Hydrophobic substances without functional groups

Hydrophilic substances

Hydrophobic substances with functional groups Detectable Faintly hydrophobic substances with functional groups

Undetectable FIG. 1. This scheme concerns the possibility of predicting the detectability organic compounds in TLC by means of fuchsine dyes.

of

examined: high aliphatic monohydroxyl alcohols, high aliphatic monocarboxyl acids, and cholesterol, together with its esters. From the group of faintly hydrophobic substances, those examined included: some derivatives of naphthalene and of barbituric acid. The group of hydrophilic compounds included phenols, monosaccharides, and glycols. The results of our investigations with a number of organic groups of substances show that the fuchsine dyes act as good visualizing reagents in the case of hydrophobic substances possessing characteristic groups, for instance -OH, -COOH, and -NH,. In the case of hydrophobic and hydrophilic substances without functional groups, the fuchsine dyes do not visualize them. The scheme in Fig. 1 illustrates the above mentioned regularities. On the base of above quoted investigations and observations, one may conclude that the conditions necessary to detect an organic substance on a thin layer by means of the fuchsine dyes are its hydrophobic properties and presence of functional groups, for instance, -OH, -COOH, and -NH, in a molecule. The above presented scheme helps to foresee the possibility of use of the fuchsine dyes as the visualizing reagents in TLC of organic substances. were

482

GREGOROWICZ

AND

SLIWIOK

REFERENCES

I. Gregorowicz. Z., Sliwiok, J., Application of new fuchsine for quantitative determination of organic substances in thin-layer chromatography. Microthem. J. 15, 545-547 (1970). 2. Sliwiok. J., On the mechanism of detecting selected organic substances by means of fuchsine dyes and the method of thin-layer chromatography. Microchem. J. 14, 376-379 (1969).