A11I-0186
Development of Novel Instrumentation to Measure All Nitrous Oxide Mono-Substituted Rare Isotopic Species

Monday, 14 December 2015
Poster Hall (Moscone South)
Xu Du, J. Brian Leen, Manish Gupta and Douglas S Baer, Los Gatos Research, Mountain View, CA, United States
Abstract:
Analysis of isotopic ratios is of great importance to study the sources and sinks of nitrous oxide (N2O) in atmosphere. N2O has four mono-substituted rare isotopic species – 14N15N16O, 15N14N16O, 14N218O, and 14N217O. Here we report on the development of novel instrumentation which is capable of measuring all four N2O isotopic species and therefore enables a complete characterization of abundance variations of these species. This instrument, which employs cavity enhanced absorption technology and a mid-infrared laser, has been developed for simultaneous measurements of all four isotopic species in either a continuous flow mode or a batch mode. A precision of better than 1 per mil for 14N217O has been achieved with samples of 10 ppm N2O in 300 seconds of measurement time. In addition, a precision of better than 1 per mil for 14N15N16O and 15N14N16O and 2 per mil for 14N218O has been achieved with samples of 300 ppb N2O or higher in 300 seconds of measurement time.