C2.1.6 - Chromatography Flashcards
How many chemical phases are in chromatography?
2
What are the chemical phases in chromatography called?
Stationary and mobile
What is the difference between a stationary and mobile phase?
Stationary - cannot move
Mobile - can move
What is the stationary phase in paper chromatography?
Absorbent paper
What is the mobile phase in paper chromatography?
Any solvent
What is the stationary phase of thin-layer chromatography?
A thin layer of silica or alumina powder spread over a plate of glass or plastic
What are paper and thin-layer chromatography used for?
Separating soluble coloured substances
Explain the process of thin-layer chromatography?
Put the solvent into a chromatography tank to a depth of about 1cm. Add a small amount of sample, taking care not to damage the powder on the plate. Let the solvent travel through the powder, and take the plate out before it reaches the top. Analyse the pattern of coloured spots
What is a chromatogram?
The graph that is created to analyse the results
What is the chromatography tank used for?
To place the substances in to start chromatography
What does the pattern produced in chromatography depend on?
How each component was distributed during each of the chemical phase
What would happen if the component forms a stronger bond with the mobile phase than the stationary phase?
It moves further up the plate
What happens if the component creates a stronger bond with the stationary phase than the mobile phase?
The component doesn’t move very far up the plate
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 unreactive carrier gas
What does gas chromatography do?
Separates the components of a mixture and also measure their amounts
Name all the equipment used in gas chromatography
Vent Flow meter Carrier gas cylinder and carrier gas Oven Detector Chromatography Column
What does the carrier gas cylinder do?
Supply the mobile phase
Where is the metal column located in during gas chromatography?
In between
What does the detector do?
Sends a signal to the computer every time a new component leaves the column
Where is the metal column detected?
In the oven
How do you calculate the Rt value?
Distance travelled by substance
————————————————-
Distance travelled by solvent
They vary from 0 to 1
