| Title: | Comparison of FTIR and particle mass spectrometry for the measurement of particulate organic nitrates |
| Author(s): | Bruns EA; Perraud V; Zelenyuk A; Ezell MJ; Johnson SN; Yu Y; Imre D; Finlayson-Pitts BJ; Alexander ML; |
| Address: | "Department of Chemistry, University of California-Irvine, Irvine, CA 92697-2025, USA" |
| ISSN/ISBN: | 0013-936X (Print) 0013-936X (Linking) |
| Abstract: | "While multifunctional organic nitrates are formed during the atmospheric oxidation of volatile organic compounds, relatively little is known about their signatures in particle mass spectrometers. High resolution time-of-flight aerosol mass spectrometry (HR-ToF-AMS) and FTIR spectroscopy on particles impacted on ZnSe windows were applied to NH(4)NO(3), NaNO(3), and isosorbide 5-mononitrate (IMN) particles, and to secondary organic aerosol (SOA) from NO(3) radical reactions at 22 degrees C and 1 atm in air with alpha- and beta-pinene, 3-carene, limonene, and isoprene. For comparison, single particle laser ablation mass spectra (SPLAT II) were also obtained for IMN and SOA from the alpha-pinene reaction. The mass spectra of all particles exhibit significant intensity at m/z 30, and for the SOA, weak peaks corresponding to various organic fragments containing nitrogen [C(x)H(y)N(z)O(a)](+) were identified using HR-ToF-AMS. The NO(+)/NO(2)(+) ratios from HR-ToF-AMS were 10-15 for IMN and the SOA from the alpha- and beta-pinene, 3-carene, and limonene reactions, approximately 5 for the isoprene reaction, 2.4 for NH(4)NO(3) and 80 for NaNO(3). The N/H ratios from HR-ToF-AMS for the SOA were smaller by a factor of 2 to 4 than the -ONO(2)/C-H ratios measured using FTIR. FTIR has the advantage that it provides identification and quantification of functional groups. The NO(+)/NO(2)(+) ratio from HR-ToF-AMS can indicate organic nitrates if they are present at more than 15-60% of the inorganic nitrate, depending on whether the latter is NH(4)NO(3) or NaNO(3). However, unique identification of specific organic nitrates is not possible with either method" |
| Keywords: | "Environmental Monitoring/methods *Mass Spectrometry Nitrates/*chemistry Nitrogen/chemistry Particulate Matter/*chemistry *Spectroscopy, Fourier Transform Infrared;" |
| Notes: | "MedlineBruns, Emily A Perraud, Veronique Zelenyuk, Alla Ezell, Michael J Johnson, Stanley N Yu, Yong Imre, Dan Finlayson-Pitts, Barbara J Alexander, M Lizabeth eng Comparative Study Research Support, U.S. Gov't, Non-P.H.S. 2010/01/12 Environ Sci Technol. 2010 Feb 1; 44(3):1056-61. doi: 10.1021/es9029864" |
