Thermal ionization mass spectrometry (TIMS) is a highly accuracy isotope characterization technique. Thanks to the multicollector system, up to five isotopes are detected at the same time. This ensure the achievement of the best results. The isotopic ratios of nuclides can be also used to get an accurate measurement for the elemental analysis of a sample. 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. 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.
Potential Results
The measurement of the isotopic ratio of some elements (Sr, Pb) allows to investigate the origin of the archaeological find. For example, in the case of ancient coins or metal objects containing lead, its isotopic ratio is related to the mines in which the mineral used to produce them was extracted. With regard to the isotopic ratio of Sr measured in bone or teeth of human finding, it allows to study the mobility of ancient populations.