Chromatography

Question 1

What is paper chromatography ?

Answer 1

• Small amount of the mixture to be separated is dissolved in a solvent
• A drop or two is put onto a pencil drawn line, the stationary phase
• the stationary phase is water molecules bond to the chromatography paper
• By capillary action the solvent i.e the mobile phase soaks up into the chromatography paper

Question 2

What is thin layer chromatography ?

Answer 2

• The origin line is drawn, this is where all the samples are placed.
• The stationary phase is the samples being placed on the tlc plate an absorbent material
• The mobile phase is the solvent separating the samples, moving up the plate, this creates a wavy line known as the solvent front.
• The retention factor is calculated
• Thin layer chromatography is used for organic mixtures like drugs

Question 3

What is gas chromatography ?

Answer 3

• The samples are injected into the oven
• The mobile phase is a carrier gas , that moves the sample through the thin long column
• The stationary phase is the samples being absorbed in the column
• The time taken for the sample to leave the column is called the retention time
• Gas chromatography is used for hear stable organic compounds due to their being an oven.

Question 4

What is High performance liquid chromatography ?

Answer 4

• The sample is injected into the machine.
• The mobile phase is the liquid that pumps the sample through the column.
• The stationary phase is the samples being absorbed in the column
• The time taken for the sample to leave the column is called the retention time
• HPL chromatography is used for heat unstable organic compounds due to its mobile phase not being a gas and instead a liquid