The instrument will be used for high-precision (order 0.001‰) measurements of dissolved N2 in water samples, via dual-inlet analyses. Dissolved gas samples will be extracted, purified, and transferred offline into the detachable dip tubes, that can be connected to one side of the dual inlet. The other side will be attached to a custom reference gas comprising N2, Ar, and Kr. Intended applications are for quantification of excess (biogenic) N2 in aquatic systems arising from nitrate reduction, using Ar and Kr to correct for physical processes impacting the N2/Ar ratio (e.g., bubble injection at the water table in a groundwater system and temperature dependent solubility effects), while N2 isotopes will be used to identify the source and processing signals associated with denitrification.