mass spectrometry

• What technique is used to identify isotopes in a sample?

  Mass spectrometry
• What are the steps involved in mass spectrometry?

  1. Ionisation
  2. Acceleration
  3. Detection
• How is ionisation achieved in mass spectrometry?

  By firing high energy electrons at the sample
• What component emits electrons in the ionisation step?

  Electron gun
• What forms when electrons are emitted from the electron gun?

  1+ ions
• What happens to the 1+ ions after ionisation?

  They are attracted to a negatively charged plate
• What is the purpose of the acceleration step in mass spectrometry?

  To give ions the same kinetic energy
• How are positive ions accelerated in mass spectrometry?

  Using an electric field
• What occurs during the detection step of mass spectrometry?

  Positive ions gain electrons and generate current
• What does the size of the electric current indicate in mass spectrometry?

  The number of ions hitting the plate
• What do the axes represent in a mass spectrometry graph?

  • Y-axis: Abundance of ions (height of peaks)
  • X-axis: Mass/charge ratio (m/z)
• How is the mass/charge ratio (m/z) determined in mass spectrometry?

  It is effectively the mass of each ion
• What does a taller peak on the mass spectrometry graph indicate?

  More of the isotope is present