The New TLC Method for Separation and Determination of Multicomponent Mixtures of Plant Extracts.

Elżbieta Matysik,Roman Paduch,Beata Polak,Helena Donica,Robert Rejdak,Anna Woźniak

doi:10.1155/2016/1813581

Abstract

The new mode of two-dimensional gradient thin layer chromatography (MGD-2D TLC) has been presented. Short distance development of sample in the first dimension leads to formation of the preconcentrated narrow zones. They are consecutively separated in the second dimension with the mobile phase gradient in several steps of development until the eluent reaches the further end of the chromatographic plate. The use of the above-mentioned technique allows isolating and then identifying the compounds of various polarity from the multicomponent mixture. The practical application of two-dimensional gradient thin layer chromatography has been performed for isolation of the two plant (Juniperus and Thymus) oils components as the examples of test mixtures. The experiments have been carried out with the use of silica gel plates as well as a normal phase condition. The results of solute separation with isocratic one-dimensional thin layer chromatography system have been compared with those of two-dimensional gradient system. It has been observed that application of the latter mode leads to almost triplicated number of zones in comparison with the former one. It is purposeful to apply the proposed mode to control the purity of the dominant component or components of the mixture.

Highlights

The separation and determination of compounds in multicomponent mixtures, that is, plant extracts, are usually performed with the use of high performance liquid chromatography, HPLC (e.g., [1, 2]), or planar chromatography (e.g., [3,4,5])
The sample components are identified by comparison of their retardation factor (RF) values with those of the separated standards
The aforementioned technique has some drawbacks owing to the differences in conditions of the separation process onto two chromatographic plates, what may cause errors in identification of the components of the plant extract

Summary

Introduction

The separation and determination of compounds in multicomponent mixtures, that is, plant extracts, are usually performed with the use of high performance liquid chromatography, HPLC (e.g., [1, 2]), or planar chromatography (e.g., [3,4,5]). The aforementioned technique has some drawbacks owing to the differences in conditions of the separation process onto two chromatographic plates, what may cause errors in identification of the components of the plant extract. It especially concerns compounds with similar polarity. Journal of Analytical Methods in Chemistry onto the distinct ends of the chromatographic plate has been presented in [7] Authors have separated both zones in two directions. The separated extract and separated mixture of standards form mirror images Both types of spots (separated sample compounds and standards) migrate identical distance from the line dividing the chromatogram onto two parts [7]. New method has been successfully verified by the separation of two plant extracts (Juniperi Oleum and Thymi Oleum)

Experimental

Results and Discussion

Conclusions