Topic 7 - Mass spectrometry

Question 1

What is the molecular ion peak?

Answer 1

The result of a molecule losing an electron.

Question 2

What is the M+1 peak?

Answer 2

Just right of the molecular ion peak and is caused by a naturally occurring carbon 13 isotope.

Question 3

What causes other peaks on a mass spectra?

Answer 3

Fragmentations, all positive ions

Question 4

What is the base peak?

Answer 4

Ion with highest abundance and has a relative abundance of 100%. It’s the most stable fragment.

Question 5

Give an example of a fragment from ethanol.

Answer 5

Positive methyl ion

Question 6

what do you add to an organic molecule to get an ion?

Answer 6

1 electron

Question 7

How are atoms ionized in a mass spectrometer?

Answer 7

Fast moving electrons are fired at sample resulting in the loss of an electron.

Question 8

Use of mass spectrometers?

Answer 8

Testing of new pharmaceuticals
Testing blood samples for traces of steroids

Question 9

What does the magnetic field inside a mass spectrometer do?

Answer 9

Separates ions of different masses.
Deflect ions

Question 10

What does the electric field in a mass spectrometer do?

Answer 10

Speeds up ions