文档介绍：GAS LIQUID CHROMATOGRAPHY
Principles
Partition of molecules between gas (mobile phase) and liquid (stationary phase).
mon Stationary Phases
1. Separation of mixture of pounds
Carbowax 20M (polyethylene glycol)
2. Separation of mixtures of non-pounds
OV101 or SE-30 (polymer of methylsilicone)
Methylester of fatty acids
DEGS (diethylene glycol inate)
Filters/Traps
Air
Hydrogen
Gas Carrier
Column
Gas Chromatography
gas system
inlet
column
detector
data system
Data system
Syringe/Sampler
Inlets
Detectors
Regulators
H
RESET
Schematic Diagram of Gas Chromatography
DETECTORS
Flame Ionization Detector (Nanogram - ng)
 
High temperature of hydrogen flame (H2 +O2 + N2) pounds eluted from column into flame. The ions collected on collector or electrode and were recorded on recorder due to electric current.
Exhaust
Chimney
Igniter
Hydrogen
Inlet
Column
Effluent
Polarizing Electrode
Collector Electrode
Schematic Diagram of Flame Ionization Detector
Schematic Diagram of Flame Ionization Detector
Collector
Jet
Flame
Detector electronics
- 220 volts
Column
Chassis ground
Signal output
Thermal Conductivity Detector
Measures the changes of thermal conductivity due to the sample (mg). Sample can be recovered.
Thermal Conductivity Detector
Principal: The thermal balance of a heated filament
Electrical power is converted to heat in a resistant filament and the temperature will climb until heat power loss form the filament equals the electrical power input.
The filament may loose heat by radiation to a cooler surface and by conduction to the ing into contact with it.