Measurement of the Half-life of 79Se by Tandem-Accelerator Mass Spectrometry (AMS) (CAT#: STEM-ST-1667-CJ)

Accelerator Mass Spectrometry (AMS) is an ultra-sensitive analytical technique based on the use of an ion accelerator as a powerful mass spectrometer. In common with other kinds of mass spectrometry, AMS is performed by converting the atoms in the sample into a beam of fast moving ions (charged atoms). The mass of these ions is then measured by the application of magnetic and electric fields.

Analytical Chemistry; Physics

1. Biological sample is converted to graphite (pure carbon)
2. Graphite sample is loaded onto AMS instrument
3. AMS analysis is performed
4. Ratio of 14C to 13C and of 13C to 12C are measured
5. Ratio of 14C to 12C is calculated, and converted to ng-equivalents/mL

• Sample: Archaeological Samples (e.g. fossils, pottery); Geological Samples (e.g. rocks, sediments/peat); Fuels; Flue; Gases; Natural Samples (e.g. rainwater); Wood; Charcoal; Bone; Bone Collagen; Hair/Fibers; Carbonates; Calcined Bone; Drugs & More
• Equipment: Accelerator Mass Spectrometry (AMS)

1. AMS can outperform the competing technique of decay counting for all isotopes where the half-life is long enough. Other advantages of AMS include its short measuring time as well as its ability to detect atoms in extremely small samples.
2. Due to the sensitivity of accelerator mass spectrometers, carbon dating small particles like blood particles, a grain, or a seed have been made possible.
3. Accelerator mass spectrometry also takes less time to analyze samples for carbon 14 content compared to radiometric dating methods that can take one or two days. An accelerator mass spectrometer has a run time of a few hours per sample.