How are stable isotopes used in forensics?
Stable isotopes in teeth provide investigators with detailed records of where a person was living when they were formed. Unlike other tissues in the body, the isotopic composition of teeth never change. Unlike hair and fingernails, most tissues do not record in linear fashion where a person was or what they ate.
What is stable isotope ratio analysis?
Stable Isotope Ratio Analysis (SIRA) testing uses isotopes of certain elements that are naturally occurring. An isotope is an atom of the same chemical element that has the same number of protons but a different number of neutrons in their nuclei. For SIRA we only use stable (i.e. non-radioactive) isotopes.
What is stable isotope used for?
Stable isotopes have helped uncover migratory routes, trophic levels, and the geographic origin of migratory animals. They can be used on land as well as in the ocean and have revolutionized how researchers study animal movement.
How do isotopes end up in hair?
When people drink the water in a given region, the isotopes end up in their hair in the same concentrations.
What is another term for stable isotope?
The term stable isotope has a meaning similar to stable nuclide, but is preferably used when speaking of nuclides of a specific element. Hence, the plural form stable isotopes usually refers to isotopes of the same element. This field is termed stable isotope geochemistry.
What can isotope analysis tell us?
Isotope analysis can be used by forensic investigators to determine whether two or more samples of explosives are of a common origin. Most high explosives contain carbon, hydrogen, nitrogen and oxygen atoms and thus comparing their relative abundances of isotopes can reveal the existence of a common origin.
How do you know which isotope is more stable?
Isotopes of elements with atomic number (Z) less than 20 and with a neutron to proton ratio of close to 1 are more likely to be stable if the nucleus contains an even number of protons and an even number of neutrons.