Evidence for high molecular weight nitrogen-containing organic salts in urban aerosols.

Published

Journal Article

High molecular weight (M(w)) species were observed at substantial intensities in the positive-ion mass spectra in urban Shanghai aerosols collected from a single-particle time-of-flight mass spectrometer (in the m/z range 250-500) during three separate periods over 2007-2009. These species correlate well with the CN(-) mass signal, suggesting that C-N bonds are prevalent and that the observed high-M(w) species are potentially nitrogen-containing organic salts. Anti-correlation with the ambient O(3) concentration suggests that photochemical oxidants are not involved directly in the formation of these species. The Mannich reaction, among amines (or ammonia), formaldehyde, and carbonyls with an adjacent, acidic proton, is proposed as a plausible pathway leading to these organic salts. Although the high-M(w) species observed in the single-particle mass spectra appear to be nitrogen-containing organics, further chemical confirmation is desired to verify if the proposed Mannich reaction can explain the formation of these high-M(w) species in regions where ammonia, amines, and carbonyls are prevalent.

Full Text

Duke Authors

Cited Authors

  • Wang, X; Gao, S; Yang, X; Chen, H; Chen, J; Zhuang, G; Surratt, JD; Chan, MN; Seinfeld, JH

Published Date

  • June 2010

Published In

Volume / Issue

  • 44 / 12

Start / End Page

  • 4441 - 4446

PubMed ID

  • 20476743

Pubmed Central ID

  • 20476743

Electronic International Standard Serial Number (EISSN)

  • 1520-5851

International Standard Serial Number (ISSN)

  • 0013-936X

Digital Object Identifier (DOI)

  • 10.1021/es1001117

Language

  • eng