1. Types of Gas Chromatography
l Gas liquid chromatography GLC
The mechanism of separation is based upon the partition of the analyte
between gaseous M.F. and a liquid S.F. immobilized on the surface of an inert
solid
l Gas solid chromatography GSC
GSC is based upon adsorption of gaseous substance on solid surfaces.
GLC Instrument
• Carrier gas supply ( M.F.)
• Sample injection system
• Column configuration and column ovens
• Detector systems
• Readout systems

3. HPLC Instrument
1-Mobile-Phase Reservoirs
One or more glass or stainless steel reservoirs
2-Pumping Systems
3-Sample Injection Systems:
Syringe injection through a self-sealing elastomeric septum
4-Chromatographic Columns
-Guard Columns
Ø Remove impurities from solvent
Ø Saturates mobile phase with liquid of stationary phase before the analytical column
- Analytical Column
Copper or stainless steel tubing straight, 15 to 150 cm in length; 2 to 3 mm packing - silica
gel, alumina, ….
5-Column Thermostats
6-Detectors

4. Mechanisms of chromatography
n Adsorption
A charge interaction occur between the active group of the sample and the sorbent S.F.
n Partition
The separation depends upon the distribution of the compound of the mixture between the
mobile phase and a liquid stationary phase according to partition coefficient value.
n Ion Exchange
Ion exchange contains labile ions that are capable of exchanging with ions of the
same change in the sample.

5. Ion-Exchange chromatography
Based upon exchange equilibria between ions in solution and ions of like sign on the surface of
an insoluble , high-molecular-weight solid .
Clay and zeolites ,
synthetic ion-exchange resins .
Formed during emulsion copolymerization of styrene and divinylbenzene.
The mobile phase are aqueous solutions that may contain moderate amount of methanol or
other water-miscible organic solvents .