C33- Chromatography

Question 1

What is chromatography?

Answer 1

Analytical technique used to separate and identify component molecules of a mixture. It uses a mobile phase and a stationary phase.

Question 2

What is the mobile phase?

Answer 2

Allows molecules to move over or through the stationary phase. More soluble products move further with the mobile phase.

Question 3

What is the stationary phase?

Answer 3

Stationary phase is a substance that has affinity of a molecule to the stationary phase, the shorter the distance it moves in mobile phase.

Question 4

What is an rf value?

Answer 4

Value calculated by comparing the distance moved by the mobile phase and the molecule.

Question 5

How is Thin-Layer Chromotogrpahy?

Answer 5

• Setup: Sample spots placed on baseline of coated plate
• Process: Solvent carries components up plate at different rates due to polarization the more polarized the longer spent in the mobile phase.
• Analysis: Results visible through UV light or iodine vapor

Question 6

How is Gas Chromotography?

Answer 6

Process:

• Sample is vaporized and injected into the column
• Different components travel at different speeds based on their interaction with stationary phase
• Temperature control of the column affects separation

Detection:

• Components emerge at different times (retention times) ( different based on the solubility in the moving phase)
• Detector produces peaks on chromatogram
• Peak area indicates quantity of component