Thermal ionization mass spectrometry

Thermal ionization mass spectrometer. Vacuum chamber on the left, electromagnet in the center, and ions detector on the right are visible.

Thermal ionization mass spectrometry (TIMS) is also known as surface ionization and is a highly sensitive isotope mass spectrometry characterization technique. The isotopic ratios of radionuclides are used to get an accurate measurement for the elemental analysis of a sample.[1] Singly charged ions of the sample are formed by the thermal ionization effect. A chemically purified liquid sample is placed on a metal filament which is then heated to evaporate the solvent. The removal of an electron from the purified sample is consequently achieved by heating the filament enough to release an electron, which then ionizes the atoms of the sample.[2] TIMS utilizes a magnetic sector mass analyzer to separate the ions based on their mass to charge ratio. The ions gain velocity by an electrical potential gradient and are focused into a beam by electrostatic lenses. The ion beam then passes through the magnetic field of the electromagnet where it is partitioned into separate ion beams based on the ion's mass/charge ratio. These mass-resolved beams are directed into a detector where it is converted into voltage. The voltage detected is then used to calculate the isotopic ratio.[3]

  1. ^ Becker, Johanna Sabine (30 August 2012). "Chapter 13 Inorganic Mass Spectrometry of Radionuclides". In L'Annunziata, Micheal F. (ed.). Handbook of radioactivity analysis (3rd ed.). Elsevier Science. p. 833-870. ISBN 978-0-12-384873-4.
  2. ^ A Handbook of Silicate Rock Analysis. ISBN 978-94-015-3990-6.
  3. ^ Constantinos A. Georgiou; Georgios P. Danezis. "chapter 3- Elemental and Isotopic Mass Spectrometry". In Pico, Yolanda (ed.). Advanced mass spectrometry for food safety and quality (68 ed.). p. 131-243. ISBN 978-0-444-63340-8.