《食品化学与分析 Food Chemistry and Analysis》课程PPT教学课件（英文版）Gas Liquid Chromatography

GAS LIQUID CHROMATOGRAPHY Principles Partition of molecules between gas (mobile phase) and liquid (stationary phase)

GAS LIQUID CHROMATOGRAPHY Principles Partition of molecules between gas (mobile phase) and liquid (stationary phase)

Most Common Stationary Phases 1. Separation of mixture of polar compounds Carbowax 20M (polyethylene glycol) 2. Separation of mixtures of non-polar compounds OV101 or SE-30 (polymer of methylsilicone) 3. Methylester of fatty acids DEGS (diethylene glycol succinate)

Most Common Stationary Phases 1. Separation of mixture of polar compounds Carbowax 20M (polyethylene glycol) 2. Separation of mixtures of non-polar compounds OV101 or SE-30 (polymer of methylsilicone) 3. Methylester of fatty acids DEGS (diethylene glycol succinate)

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

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

Schematic Diagram of Gas Chromatography

Schematic Diagram of Gas Chromatography

Schematic Diagram of Gas Chromatography

DETECTORS Flame Ionization Detector (Nanogram - ng) High temperature of hydrogen flame (H2 +O2 + N2 ) ionizes compounds eluted from column into flame. The ions collected on collector or electrode and were recorded on recorder due to electric current

DETECTORS Flame Ionization Detector (Nanogram - ng) High temperature of hydrogen flame (H2 +O2 + N2 ) ionizes compounds 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

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

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 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 molecules coming into contact with it

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 molecules coming into contact with it