1. Introduction to mass spectrometry

3. Electron Impact Ionisation Mass Spectrometry (EIMS) The sample is vaporised and ionised in the ion source of the mass spectrometer. Ionisation occurs via bombardment of the sample with a stream of high energy electrons.

4. The stream of high energy electrons is produced from an electrically heated tungsten or rhenium filament. Impact of the high energy electrons with the vaporised samples molecules causes the ejection of one/more electrons from the analyte and a radical cation M+ (the molecular ion) is formed: M + e-  M+ + 2e-

6. Immediately after ionisation, the sample ions (M+) are accelerated into the mass analyser using a series of electronic lenses in order to increase their kinetic energy.

8. Immediately after acceleration through an electric field of approximately 8kV the ions enter a magnetic field where they are paths are deflected according to their mass/charge ratio

10. boron

11. zirconium

12. chlorine

13. Resolution: EIMS Spectra of Chloroethane

14. EIMS Spectra of Paracetamol  -Cleavage