The TIMS system Thermal ionization mass spectrometer TRITON
The filament turret The filaments The ion source
Model
Thermal Ionization Mass Spectrometer TRITON
(Thermo Fisher Scientific K. K.)

Overview

This analytical system is used for analysis of stable isotopic ratios of not only natural samples but also farm and marine products and artificial materials. It has been applied for studies on geochemistry covering solid-state materials (i.e. rocks and minerals). In RIHN, it is applied for studies on various environmental samples including water, atmospheric fallout, soil, living things, farm and marine products, food, biological minerals (e.g. bones and teeth), archeaological materials, etc.

Using this analytical system, stable isotopic ratios of Sr, Pb, and Nd in environmental samples are mainly analyzed. It is the most advanced analytical instrument applied for studies on identification of sources of environmental materials, an assesment of environmental impact, environmental restoration, etc.

Principle

The chemically-purified materials are extracted from various environmental samples using positive ion chromatography. They are loaded on the filament degassed in the filament oven, and then the filaments are set inside the ion source of the mass spectrometer.

The ions created on the filament are acceralated across an electrical potential graidient, and focused into a beam via a series of slits and electrostaticalliy charged plates. The ion beam passes through a magnetic field and it is separated on the basis of their mass/charge ratios. The separated beams are then introduced into collectors, and the isotopic ratios are measured precisely.

The necessary sample size is less than 1 µg. This analytical instrument can achieve the analytical precision of less than 10-5 in repeated measurement.

Filament Oven
This instrument is used for purification of the metal filaments by degassing of the impurities from metals.

The metal filaments, which are made of Ta, Re, or W, are set in the chamber, and then the chamber is highly evacuated. The filaments are electrically heated at more than 1000°C to remove the impurities. The impurities are evacuated by the pump.

Sample Loader
Using this instrument, the chemically-purified materials extracted from the environmental samples are loaded on the degassed metal filaments. It can carry out loading on 5 filaments simultaneously.

Aftet the sample materials are loaded on the metal filaments, the filaments are heated with adding chemical solutions which can accelerate or inhibit vaporization of stable isotopes in the sample materials.