How does isotope testing work?

By measuring the ratios of different isotopes in bones or teeth and using scientific knowledge about how they occur in nature to trace them back to the sources that they came from, archaeologists can find out many things about an individual, such as what their diet was like and the environment they grew up in.

What do isotopes tell us?

Isotopes are members of a family of an element that all have the same number of protons but different numbers of neutrons. The number of protons in a nucleus determines the element’s atomic number on the Periodic Table.

What is isotopic analysis mainly used for in forensics?

While isotope analysis has been used for several decades to determine whether samples of chemically similar substances – such as drugs, explosives, paints, plastics, or tapes – may share a common source, applications of the technique to unidentified human remains for forensic profiling purposes are continuing to emerge …

How do you measure isotopes?

For stable isotopes, atoms of each isotope are counted using a mass spectrometer. This turns atoms into charged ions and separates them into the different isotopic species using a mass filter. Precise measurements of isotopic abundance can be achieved in a few minutes or hours.

Why are isotopes useful?

Radioactive isotopes differ in the stability of their nuclei. Measuring the speed of decay allows scientists to date archaeological finds, and even the universe itself. Stable isotopes can be used to give a record of climate change. Isotopes are also commonly used in medical imaging and cancer treatment.

How are stable isotopes used?

Stable isotopes can be used by measuring their amounts and proportions in samples, for example in water samples. Naturally-occurring stable isotopes of water and other substances are used to trace the origin, history, sources, sinks and interactions in water, carbon and nitrogen cycles.

Why are isotopes so important?

Isotopes of an element all have the same chemical behavior, but the unstable isotopes undergo spontaneous decay during which they emit radiation and achieve a stable state. This property of radioisotopes is useful in food preservation, archaeological dating of artifacts and medical diagnosis and treatment.

How are isotopes used in forensic science?

Crime scene investigation For example, stable isotope analysis is used to identify drug trafficking routes, to determine whether explosives are of a common origin, as well as locating the country of origin for a given explosive. Stable isotope analysis is also used to trace counterfeit pharmaceuticals and food fraud.

What can isotope analysis be used for?

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 are isotope ratios used in forensic science?

For forensic purposes, isotope ratios of different elements like carbon, nitrogen, oxygen, and hydrogen will vary based on a person’s exposure to environmental factors such as drinking water and nutrients in food. Therefore, isotope ratios can be used as a molecular signature to reflect an individual’s habits and daily exposure to the environment.

How are isotopes used to measure environmental factors?

Isotopes are different forms of the same chemical element that can be measured accurately and compared. For forensic purposes, isotope ratios of different elements like carbon, nitrogen, oxygen, and hydrogen will vary based on a person’s exposure to environmental factors such as drinking water and nutrients in food.

How are carbon and nitrogen used in forensics?

Carbon and nitrogen are two other elements commonly used by forensic scientists. Like hydrogen and oxygen, carbon and nitrogen are found throughout our bodies. But instead of chronicling the water supply, they reflect people’s diets. Carbon in our bodies is largely derived from plant tissues, which get their carbon from CO 2 in the atmosphere.

What kind of mass spectrometer is used for stable isotope analysis?

A time of flight secondary ion mass spectrometer (TOF-SIMS) used to analyze the stable isotope composition of surfaces. Lesley Chesson works at Salt Lake City-based IsoForensics, the company that received the hair sample.