C2.1.6 - Chromatography Flashcards
What is chromatography?
A separation method that relies on the distribution of a substance between a mobile phase and stationary phase
What is the mobile phase?
A substance in the liquid or gas state that moves during chromatography
What is the stationary phase?
A substance in the solid or liquid state that does not move during chromatography
What is paper chromatography used for?
To separate the coloured substances in ink or sweets?
What is the stationary phase in paper chromatography?
Absorbent paper
What is the mobile phase in paper chromatography?
A solvent in the liquid state
What is thin-layer chromatography?
Chromatography in which compounds are separated on a thin layer of absorbent material
What is the mobile phase in thin-layer chromatography?
A solvent in the liquid state
What is the stationary phase in thin-layer chromatography?
A thin layer of silica or aluminised powder
In thin-layer chromatography a component travels further up the plate if
It forms stronger bonds with the mobile phase than the stationary phase
In thin layer chromatography a component will not travel very far if
It forms stronger bonds with the stationary phase with the mobile phase
What does gas chromatography do?
It separates the components of a mixture and also measures their amounts
What is the stationary phase in gas chromatography?
Silica or alumina powder packed into a metal column
What is the mobile phase in gas chromatography?
An unread five carrier gas which does not react with the sample
How does gas chromatography work?
The sample is turned into the gas state when it is injected into the column
The carrier gas pushes the sample through the column
Different components take different times to travel through the column depending on how strong they bond to the stationary phase
A detector sends a single to a computer as each component leaves the column
The computer produces a chromatogram in which each component is a peak plotted against the travel time
