Chromatography Flashcards
How do you find the Rf value?
Distance moved by spot/Distance moved by solvent
What is the retention time?
The time taken from injection until a component reaches the detector.
What is the stationary phase of paper chromatography?
Water in paper
What is the mobile phase of paper chromatography?
Solvent (eg hexane)
Method of separation
Partition
What does a high Rf value mean?
Compound spends most its time in the mobile phase.
What does a low Rf value mean?
Compound spends most of its time in the stationary phase.
What is the stationary phase of Thin layer chromatography?
Silica (or alumina) supported on rigid sheer of aluminium or glass.
What is the mobile phase of thin layer chromatography?
Suitable solvent or mixture of solvents.
What is the method of separation for thin layer chromatography?
Adsorption
What is the stationary phase of gas-liquid chromatography?
Thin layer of solid or liquid.
What is the mobile phase of gas-liquid chromatography?
Unreactive gas e.g nitrogen or helium.
What is the value recorded for paper chromatography?
Rf value.
What is the value recorded for thin-layer chromatography?
Rf value?
What is the value recorded for gas-liquid chromatography?
Retention time.
