Chromatography, Gas Chromatography and Mass Spectroscopy

Question 1

Describe how Chromatography works.

Answer 1

Dots of ink put on a pencil baseline. The solvent rises up paper and dissolves ink pigments. The more soluble the pigment, the further it travels up the paper. This means the pigment is separating.

Question 2

What does gas chromatography do?

Answer 2

Separates mixtures that have low boiling points.

Question 3

Describe the steps of Gas chromatography.

Answer 3

• Sample injected.
• Carrier gas carries sample through heated column.
• Compounds separate as they move through column. because they travel at different speeds.
• First compound to leave the column is detected and a peak appears on the chromatogram.
• the chromatogram shows the retention time(time taken to travel through column).

Question 4

Name 3 advantages of gas chromatography.

Answer 4

• Fast.
• Provides more accurate results.
• Only needs small samples as very sensitive.

Question 5

Why is nitrogen usually used as the carrier gas during gas chromatography?

Answer 5

Nonreactive

Question 6

What does a mass spectrometer do?

Answer 6

Detects relitive formula mass of a compound and produces a print out called a mass spectrum.

Question 7

On a mass spectrum the peak at the highest mass tells us what?

Answer 7

Relative molecular mass of a compound.