Oxygen17

Oxygen-17, often written as 17O, is a stable isotope of oxygen with mass number 17. It occurs in nature at a very low abundance, about 0.037% of natural oxygen, with the remaining majority consisting of 16O (≈99.757%) and 18O (≈0.205%). Because of its rarity, 17O is typically studied in labeled or enriched samples.

Nuclear properties of 17O include eight protons and nine neutrons. The nucleus has a nuclear spin of I = 5/2, making it a quadrupolar nucleus. The quadrupole moment leads to line-broadening effects in NMR spectra and requires specialized techniques and often isotopic enrichment to obtain high-resolution data. As a stable isotope, 17O does not undergo radioactive decay, which makes it suitable for long-term laboratory studies.

Applications of 17O are most prominent in spectroscopy and isotope tracing. 17O NMR spectroscopy is used to investigate oxygen-containing functional groups, hydration shells, and exchange processes in chemistry and biochemistry. Enriched 17O labels, such as H2^17O or ^17O-labeled organic or biomolecules, enable researchers to monitor water transport, oxygen exchange, and reaction mechanisms at a molecular level. In geochemistry and environmental science, 17O serves as a tracer for isotopic studies of water sources and mineral formation, complementing the more abundant 16O and the heavier 18O isotopes.

Production and enrichment of 17O rely on isotope separation methods, including cryogenic distillation and chemical exchange processes. Natural abundance is too low for detailed study, so researchers obtain enriched 17O samples to achieve practical signals in NMR and other analytical techniques.