Thermal Ionization Mass Spectrometry (TIMS)

Thermal ionization mass spectrometry, (TIMS) is a highly sensitive isotope characterization technique that determines the isotopic composition of an individual element. 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. In the mass spectrometer, the removal of an electron from the purified sample is achieved by heating the filament, which then ionizes the atoms of the sample. TIMS utilizes a magnetic sector mass analyser 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.