Under current conditions, measurements of in-house standards and reference materials showed that the linearity of measured δ 15 N values were in good agreement with both literature and referenced δ 15 N values from an EA-IRMS system. Because of the early state of the modified system, this study can be interpretated as a proof of principle. Major challenges that should be addressed in the future include (i) reducing the nitrogen background from the eluent, (ii) modifying the copper reactors to operate in parallel to enable simultaneous regeneration of oxidized copper wires and (iii) reducing peak broadening by testing different column materials and optimizing flow conditions both in the liquid and gas phase. In addition, positioning of the switching valve heads into a nitrogen free gas atmosphere could reduce the amount of air entering the system. These modifications will likely address the observed issues of low sensitivities as well as drifting isotope signatures over time. A separation and measurement of both nitrite and nitrate with one measurement might be possible if separation with other HPLC columns can be optimized.