|
|
|
| TLC - Thin Layer ChromatographyHPLC - High Pressure Liquid ChromatographyIntroduction
Thin Layer Chromatography (TLC) is a method for identifying substances and testing the purity of compounds.TLC is a useful technique because it is relatively quick and requires small quantities of material.High Pressure Liquid Chromatography (HPLC) is a modern adaptation of TLC with improved separation efficiency and detection limits. HPLC can be used to determine the identity and bulk purity of botanicals and their extracts or compendial drug substances. Method
Thin-layer chromatography consists of a stationary phase immobilized on a glass or plastic plate, and an organic solvent. The sample, either liquid or dissolved in a volatile solvent, is deposited as a spot on the stationary phase. The stationary phase is a thin layer of adsorbent (usually silica gel or alumina) coated on a plate. The mobile phase is a developing liquid that travels up the stationary phase, carrying the samples with it. The bottom edge of the plate is placed in a solvent reservoir, and the solvent moves up the plate by capillary action. When the solvent front reaches the other edge of the stationary phase, the plate is removed from the solvent reservoir. Components of the samples will separate on the stationary phase according to how much they adsorb on the stationary phase versus how much they dissolve in the mobile phase. The separated spots are visualized with ultraviolet light or by placing the plate in iodine vapor. NDS Technologies manufactures several systems and component products used in Chromatography.
|
|
NDS Technologies, Inc.
Copyright © 2003 - 2006 NDS
Technologies, Inc. Website created and hosted by Philly Webmaster |
