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. Neutrons have mass, and therefore the isotopes of the same element have slightly different masses. For SIRA we only use stable (i.e. non-radioactive) isotopes.
Stable isotopes have a natural abundance but physical processes favouring one isotope over another result in the enrichment of one isotope compared to another (in the case of oxygen and hydrogen – lighter isotopes evaporate more readily and heavier ones are the first to be deposited when it rains). It is this enrichment or depletion of one isotope over another that we measure in plants and animals. Combining patterns from multiple isotopes allows us to map production and origin information to establish authentic reference datasets. Test samples can be assessed for consistency with the reference samples of known origin for example.
We are always willing to explain results, particularly if they’re not what you expect and can help you to put in place follow up mechanisms.
Our laboratory is accredited for SIRA