ABSTRACT
Chromatography is the science that studies the separation of molecules based on differences in their structures. In chromatography, a complex of compounds are separated over a stationary support, through different interactions with that support. So, according to these different (stronger or weaker) interactions with the support, this complex will move quickly or less quickly. In this way, even chemically similar molecules can be separated from each other. Chromatographic separations can be carried out using a variety of supports, including paper (paper chromatography, PC), silica on glass plates (thin-layer chromatography, TLC), volatile gases (gas chromatography, GC), and liquids, which may incorporate hydrophilic, insoluble molecules (liquid chromatography, LC) [1,2]. In all chromatographies, there is a mobile phase and a stationary one. In PC and TLC, the mobile phase is
2.1 Introduction: What is Chromatography? ................................................................................ 13 2.2 Chromatography: Then and Now ........................................................................................... 14 2.3 Overview of Chromatography Techniques ............................................................................. 14
2.3.1 The Different Types of Chromatography ................................................................... 14 2.4 Liquid Chromatography.......................................................................................................... 15
2.4.1 Ion-Exchange Chromatography .................................................................................. 15 2.4.2 Hydrophobic Interaction Chromatography (HIC) ...................................................... 16 2.4.3 Gel-Filtration Chromatography .................................................................................. 16 2.4.4 Afnity Chromatography ........................................................................................... 16
2.5 Types of HPLC ....................................................................................................................... 16 2.5.1 Normal-Phase Chromatography ................................................................................. 16 2.5.2 Reversed-Phase Chromatography ............................................................................... 16 2.5.3 Size Exclusion Chromatography (SEC) ...................................................................... 17 2.5.4 Ion-Exchange Chromatography .................................................................................. 17 2.5.5 Bio-Afnity Chromatography .................................................................................... 17 2.5.6 Isocratic Flow and Gradient Elution ........................................................................... 17
2.6 Herbal Drugs........................................................................................................................... 17 2.6.1 Overview of Herbal Quality ....................................................................................... 18 2.6.2 Use of Fingerprinting and Marker Compounds for Identication and
Standardization of Botanical Drugs ........................................................................... 19 2.6.3 Applications of HPLC Analyses to Herbal Drugs and Herbal Products .................... 19
2.7 Conclusions .............................................................................................................................20 References ........................................................................................................................................20
