(a) Structure of Mass Spectrometer

1
(a) Structure of Mass Spectrometer

• AVaporization Chamber
• BIonization Chamber
• CAccelerating Chamber
• DDeflection Chamber
• EIons detector

2
(a) Functions for each parts of Mass
Spectrometer

• AVaporization Chamber
• BIonization Chamber
• CAccelerating Chamber
• DDeflection Chamber
• EIons detector

• to vaporize the sample to be tested by heat
• molecules are bombarded by alpha/beta rays to
  form cations
• cations are accelerated by a strong electric
  field
• cations are deflected by strong magnetic field
  according to their mass/charge ratio
• amounts of ions are proportional to the electric
  current detected

3
(b) Give two reasons why such kind of mass
spectrometer cannot be used to determine the
molecular mass of biomolecules.

• (1) Because biomolecules are thermal labile,
  they would decompose in the evaporation chamber
  under strong heating
• (2) The biomolecules would be cracked by the
  bombardment with alpha/beta rays in the
  ionisation chamber

4
(b) Name the two parts in the traditional
mass spectrometer which were replaced by
electrospray ionization (ESI) technique.
Explain why such a technique can be used to
study biological macromolecules.

• ESI technique can replace the vaporization
  chamber and ionization chamber.
• As no heating and bombardment with high energy
  particles to the bio-macromolecules are required
  by using electrospray ionization technique, the
  bio-molecules would not decompose.

5
(d) Name the two parts in the traditional mass
spectrometer which were replaced by soft laser
desorption (SLD) technique. Explain why such a
technique can be used to study biological
macromolecules.

• SLD technique can replace the vaporization
  chamber and ionization chamber.
• As no heating and bombardment with high energy
  particles to the bio-macromolecules are required
  by using soft laser desorption technique, the
  bio-molecules would not decompose.

6
(e) State two advantages of applying ESI and SLD
techniques in Mass Spectrometer to study
biological macromolecules.

• The method is superior to other methods in the
  rapidity, sensitivity and identification of the
  actual interaction.
• This analytical methods are relatively cheap,
  enabling them to spread quickly to laboratories
  all around the world.
• By having a surface that cancer cells adhere to
  and then analysing this with soft laser
  desorption chemists can discover cancer faster
  than doctors can.