Analysis of N2O (nitrous oxide) via GC: an update

Nitrous oxide (N2O), is commonly known as “laughing” gas, but is also used as a component in fuels in rockets and as an aerosol propellant. N2O is itself a stable gas and can be analyzed relative easy via gas chromatography. Often it is confused with “nitric oxide”, (NO). NO is a very reactive gas. When oxygen is preset, it will immediate oxidize into NO2. NO2 can be easily recognized as it has a dark brown color. Also NO2 shows reactivity, meaning that the analysis of NO and NO2 via gas chromatography is not commonly done.

Nitrous oxide on Alumina BOND / Na2SO4 Column: 30m x 0.53mm Rt Alumina BOND / Na2SO4; Helium, 4 mL/min; Oven: 40ºC; sample: 60µl; Detector: PlasmaDetek PED; sample: 5.4 ppm N2O.Chromatogram courtesy: L. Paradis, LDetec.

Recently a summary of N2O analysis was published by Separation science. Separations are shown on different adsorbents like, Porous polymer, Alumina, Molsieve 5A and ShinCarbon materials.

Full Article can be found here: http://www.sepscience.com/Information/Archive/All-Articles/4365-/Analysis-of-Gases-via-Gas-Chromatography-Part-1-Nitrous-Oxide

Especially the alumina PLOT is interesting (Fig.1) as often CO2 is present and can interfere with the N2O measurement. CO2 is adsorbed completely by Alumina, resulting is a single N2O peak. CO2 can be removed periodically by conditioning at 200C.