The change in isotopic abundance is called fractionation ... One of the most important applications of nitrogen stable isotopes is its ability to determine the trophic level of a species.

Yet, despite its abundance in the atmosphere ... how life flourished before oxygen became prevalent. The study of nitrogen isotopes—different forms of the element with varying atomic weights ...

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. Stable isotopes can also ...

Carly Buchwald’s group uses the abundance stable isotopes of N and O in nitrite and nitrate to interpret nitrogen biogeochemistry in the environment. They measure the isotope systematics of relevant ...