| Applications | Geochemistry, geology, climate change, hydrology, food authenticity, food adulteration, ecology, petroleum geoscience, archaeology, forensics, sports doping, environmental science, oceanography | Sports doping (steroid abuse, testosterone origin), criminal forensics (drugs of abuse, explosives, counterfeits), archaeology (food sourcing, mummified materials), geographic origin determination | Flavor and fragrance industry: authenticity testing of aromas, essential oils, and flavor compounds; natural vs. synthetic discrimination; geographic origin confirmation; adulteration detection | Dissolved nitrate isotope analysis (d15N, d18O) in groundwater, surface water, seawater; atmospheric greenhouse gas analysis (CO2, N2O, CH4); nitrogen cycle research; soil and organic material isotope analysis | Upstream reservoir exploration, well profiling, unconventional resources (shale gas, coal bed methane), crude oil fingerprinting, oil spill characterization, gas source determination |