| Applications | Geochemistry, geology, paleoclimatology, hydrology, biogeochemistry: mineral sulfates/sulfides, nitrates, biogenic silicates, carbonates, apatite, soils, sediments, clays, tree rings, wood, organic materials | 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 |