Mass Spectrometer
- Created by: Hannah Kent
- Created on: 29-03-13 21:11
View mindmap
- Mass Spectrometer
- Ionisation
- A sample is placed int eh spectrometer and if it is not already a gas it is vaporized
- The atoms diffuse into the path of electrons from the electron gun and are ionised.
- The gun fires out high-energy electrons which knock out an electron from gaseous particles so that they form positive ions
- Acceleration
- the positive ions are accelerated by an electric field and focused into a beam by passing them through a series of slits.
- Deflection
- The beam of fast moving positive ions is then deflected by a strong magnetic field.
- The magnitude of the deflection depends on the mass to charge ratio (m.z) of the ion. When small: m/z is the deflection is large.
- Detection
- When the ion hits the detector it accepts an electron, and this causes a small electrical current which is amplified and produces a signal on the computer
- The magnitude of the amplified current i related to the number of ions that hit the detector and the relative intensity of the peak caused by an ion with a particular m/z value.
- The magnetic field can be increased in order to deflect heavier ions into the detector one after another and thereby produce a 'spectrum'
- Ionisation
Comments
No comments have yet been made