To carry out this research, Dr Bourbonnais’ team at the university exploit the stable isotope ratios of reactive N pools as a primary tool and tracer to study N transformations in different marine environments. Studying the coupled (δ15N and δ18O) isotopic compositions of nitrate (NO3-), nitrite (NO2-) or N2O is particularly valuable, since O and N atoms are affected differently during biological consumption and production. This allows co-occurring N processes in oceanic environments to be disentangled. N2O isotopomers, the intramolecular distribution of N in the N2O molecule, are also analyzed to resolve N source and sink terms.
In order to facilitate this work, Dr Bourbonnais and her team acquired an isoprime precisION isotope ratio mass spectrometer (IRMS) system from Elementar, equipped with a customized 11 Faraday collector array for the acquisition of nitrous oxide stable isotopes and isotopomers. The detector array also permits the simultaneous isotopic analysis of all of the common components of the atmosphere (O2, N2, and Ar). The isoprime precisION IRMS was also supplied with a Novel Inlet Control Module (NICM) allowing Dr Bourbonnais to easily develop a unique, custom built inlet system. The lab has also invested in a vario PYRO cube® elemental analyzer and vario LIQUID sampler (VLS) to further increase their analytical capabilities.