Articles | Volume 4, issue 12
Atmos. Meas. Tech., 4, 2795–2807, 2011
Atmos. Meas. Tech., 4, 2795–2807, 2011

Research article 20 Dec 2011

Research article | 20 Dec 2011

Integrated method for the measurement of trace nitrogenous atmospheric bases

D. Key, J. Stihle, J.-E. Petit, C. Bonnet, L. Depernon, O. Liu, S. Kennedy, R. Latimer, M. Burgoyne, D. Wanger, A. Webster, S. Casunuran, S. Hidalgo, M. Thomas, J. A. Moss, and M. M. Baum D. Key et al.
  • Oak Crest Institute of Science, Pasadena, California, USA

Abstract. Nitrogenous atmospheric bases are thought to play a key role in the global nitrogen cycle, but their sources, transport, and sinks remain poorly understood. Of the many methods available to measure such compounds in ambient air, few meet the current need of being applicable to the complete range of potential analytes and fewer still are convenient to implement using instrumentation that is standard to most laboratories. In this work, an integrated approach to measuring trace, atmospheric, gaseous nitrogenous bases has been developed and validated. The method uses a simple acid scrubbing step to capture and concentrate the bases as their phosphite salts, which then are derivatized and analyzed using GC/MS and/or LC/MS. The advantages of both techniques in the context of the present measurements are discussed. The approach is sensitive, selective, reproducible, as well as convenient to implement and has been validated for different sampling strategies. The limits of detection for the families of tested compounds are suitable for ambient measurement applications (e.g., methylamine, 1 pptv; ethylamine, 2 pptv; morpholine, 1 pptv; aniline, 1 pptv; hydrazine, 0.1 pptv; methylhydrazine, 2 pptv), as supported by field measurements in an urban park and in the exhaust of on-road vehicles.