An introduction to chromatography

To identify the compounds of a mixture = qualitative analysis To quantify these compounds To retrieve the separated solutes (preparative techniques) Spectroscopic methods (UV-vis, IR, RMN, MS) can also be used directly for mixtures of compounds but are limited to 2 or 3 analytes at a time. The objective of chromatographic methods is to separate the compounds present in a mixture. It is then possible to identify and quantify them. Objective of chromatographic methods

Introduction of the sample in the separative device (the sample must have been prepared for this purpose) Separation with stationary and mobile phases Detection of the separated species getting out of the chromatographic system The three steps of chromatography

A chromatogram is produced: The three steps of chromatography Analysis time Solute 1Solute 2

Basic principle of chromatographic techniques: Different affinity of the solutes for two non-miscible phases Stationary phase (SP): Solid or Liquid Mobile phase (MP): Gaseous, Liquid or Supercritical The three steps of chromatography

Gas Liquid Pressure (MPa) Temperature °C * 31°C 7.3 MPa Supercritical fluid State diagram for carbon dioxide

NON CHROMATOGRAPHY Centrifugation Electrophoresis Electrodialysis Dialysis, Osmosis Microfiltration, Ultrafiltration Reversed osmosis Field Flow Fractionation Centrifugal force Electrical Concentration gradient Pressure Driving force Method Homogeneous phase separation methods

Property Molecular size Volatility Charge Solubility Polarity Specific affinity Chirality Principles of separation used in chromatography Example Application Polymers Perfumes Amino acids Any solute Plant extracts Proteins Drugs, perfumes Technique Size Exclusion Chromatography Gas Phase Chromatography Ion Exchange Chromatography Partition Liquid Chromatography Adsorption Liquid Chromatography Thin Layer Chromatography Affinity Chromatography Chiral chromatography