Study Of Microemulsion Thin Layer Chromatography And Its Application In The Fingerprinting Of Licorice (Glycyrrhiza Spp.)

Chromatographic fingerprinting is a key technique for TCM (Traditional Chinese Medicine) modernization. Thin Layer Chromatography (TLC) has been widely used for the fingerprint study of medicinal plants owing to its some obvious advantages. However, inadequate reproducibility and relatively low resolution are two major factors hinder the widespread use of TLC in the analysis or quality control of herbal materials on a routine basis. In this thesis, a simple and easily controlling microemulsion TLC (METLC) technique has been developed. Optimization of microemulsion developing system and characteristics of METLC were all be deeply studied and the developed METLC technique has been used to assess quality of licorice. The study demonstrates the potential of METLC technique as a rapid fingerprinting tool for the authentication and quality assessment of licorice as well as other herbs. Micellar TLC, conventional TLC and HPLC method were also studied for comparison in the thesis.The dissertation consists of 6 parts: (1) A review of the current research status of METLC and the quality controlling of licorice. (2) Impact factors and optimized method on the separation of active components in licorice by micellar thin layer chromatography. (3) Impact factors on the separation of active components in licorice by microemulsion thin layer chromatography. (4) Characteristics of microemulsion thin layer chromatography and its application in two dimensional thin layer chromatography of licorice. (5) Application of METLC fingerprinting and HPLC fingerprinting in the quality controlling of licorice. (6) conclusions and recommendations for future research.