d15N in seawater

Thermo Delta V IRMS

δ15N on nitrates, nitrites and ammonia


This instrument is coupled with a Conflo lll and Precon for nitrogen isotopic composition of nitrate and nitrite of seawater


This method mainly consists of the reduction of nitrate to nitrite using spongy cadmium followed by reduction to nitrous oxide using sodium azide in an acetic acid buffer. The nitrous oxide is purged from the samples and cryogenically trapped using a modified Isomass Precon system. The isolated nitrous oxide is then analyzed on a Thermo Scientific Delta V continuous flow isotope ratio mass spectrometer. 

Associated Projects


Howarth, L. M., Filgueira, R., Haas, S., Berry, H. B., McKee, A., Steeves, L., & Grant, J. (2020). The effects of incubation time, temperature and nitrogen concentration on the isotopic signature (δ15N) of the macroalga Chondrus crispus. Journal of Experimental Marine Biology and Ecology530, 151431.