Gas liquid chromatography Flashcards
Gas liquid chromatography
Analytical technique used to separate and identify the components of mixture. Compounds are separated because they distribute themselves differently between a gas phase and a liquid phase.
Mobile phase
Inert (unreactive) CARRIER GAS eg. N2 in gas-liquid chromatography
Stationary phase
High boiling point LIQUID held on a finely divided inert porous solid support in a long thin tube in gas-liquid chromatography
What phase is a paper in paper chromatography?
stationary phase
What phase is a solvent in tlc chromatography
mobile phase
What phase is a Silica gel plate in tlc chromatography
stationary phase
Kpc
partition coefficient
Kpc formula
[stationary phase] / [mobile phase]
compounds that favour the mobile phase means = will be carried along the
… more QUICKLY
Features of gas-liquid chromatography technique
- sensitive
* can detect VERY small quantities
What does the detector on the outlet tube of the gas-liquid chromatograph do?
monitors the compounds coming OUT of the column
the x and y axis of a gas chromatogram
x-axis = retention time/*minutes* y-axis = signal from detector
Is the retention time of one molecule the same for another?
No because retention time is CHARACTERISTIC of the compound
Retention time
The time that a compound is held in a column under given conditions
What does the height of a narrow peak or area under a wide peak in a gas chromatogram represent?
amount of a molecule
