The Mass Spectrometer
- The mass spectrometer is an instrument used to determine the relative isotopic mass and the relative abundance of each isotope
- Relative isotopic mass is the mass of an individual isotope relative to the mass of carbon-12
- Apart from finding the masses of isotopes, mass spectrometry is a vey useful tool for detecting illegal drugs, forensic science, space exploration and carbon-14 dating
The components of a mass spectrometer
How the mass spectrometer works
- A sample is injected into the spectrometer where it is heated and vaporised
- The atoms or molecules are then bombarded by high energy electrons created by an electron gun
- The high energy electrons collide with the sample material and remove electrons creating positive ions
- The ions are then accelerated by attraction towards negatively charged plates
- Many ions strike the plate and are discharged, but a few will pass through a gap in the plates into a curved section of the spectrometer known as the flight tube
- The flight tube is encased in electromagnets which create a strong electromagnetic field that deflects the path of the ions in a curve
- The ions pass onto a charged detector plate where every strike is recorded as a small current which is then amplified
- By varying the electric and magnetic fields all the charged particles can be deflected to the detector which gives information about the mass/charge ratio and abundance of each ion