Composition of dissolved organic nitrogen in continental precipitation investigated by ultra-high resolution FT-ICR mass spectrometry.
The atmospheric transport of fixed nitrogen (N) is a critical component of the global N cycle that has been heavily impacted by human activities. It has been shown that organic N is an important contributor to atmospheric N, but its sources and composition are largely unknown. Rainwater samples collected in New Jersey were analyzed by negative and positive ion ultrahigh-resolution electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). Elemental compositions of 402 N-containing compounds were determined and five main groups of compound classes were identified: compounds containing carbon, hydrogen, oxygen, and N detected as positive ions (CHON+), compounds containing CHON detected as negative ions (CHON-), compounds containing CHN detected as positive ions (CHN+), and CHON compounds that contain sulfur (S) detected as both positive and negative ions (CHONS+, CHONS-, respectively). The CHON+ compound class has the largest number of compounds detected (i.e., 281), with the majority, i.e., 207, containing only one N atom. The elemental ratios of these compounds and their detection in the positive ion mode suggest that they are compounds with reduced N functionality. Known contributors to secondary organic aerosol with anthropogenic sources were also identified including organonitrate compounds and nitrooxy organosulfates.
Altieri
Katye E
KE
Institute of Marine and Coastal Sciences, Rutgers University, 71 Dudley Road, New Brunswick, New Jersey 08901, USA. altieri@marine.rutgers.edu
Turpin
Barbara J
BJ
Seitzinger
Sybil P
SP
D000596:Amino Acids / Q000032:analysis; D002244:Carbon / Q000032:analysis; D017357:Cyclotrons / Q000295:instrumentation*; D005583:Fourier Analysis; D006859:Hydrogen / Q000032:analysis; D013058:Mass Spectrometry / Q000379:methods*; D009566:Nitrates / Q000032:analysis; D009584:Nitrogen / Q000032:analysis*; D009930:Organic Chemicals / Q000032:analysis*; D010084:Oxidation-Reduction; D011891:Rain / Q000737:chemistry*; D012995:Solubility; D013455:Sulfur / Q000032:analysis
D000596:Amino Acids; D009566:Nitrates; D009930:Organic Chemicals; D013455:Sulfur; D002244:Carbon; D006859:Hydrogen; D009584:Nitrogen