title: Atmospheric pressure mass spectrometry: a new analytical chemical characterization method for dissolved organic matter in rainwater.
abstract: The complex mixture of organic compounds in the atmosphere influences climate, air quality, and ecosystem processes. Atmospheric pressure electrospray ionization mass spectrometry (APESI-MS) was evaluated as a potential tool for direct measurement of the total suite of individual dissolved organic matter (DOM) compounds in rainwater. The APESI-MS response was linear to all DOM compounds of atmospheric significance examined as standard solutions. Urban precipitation samples from New Brunswick, NJ (USA) were analyzed by APESI-MS over the mass-to-charge (m/z) range 50-3,000. Over 95% of the m/z ions detected were in the low m/z range (50-500). Over 300 unique m/z ions were detected across the 11 rainwater samples indicating the complexity of the mixture of DOM in rainwater. Forty percent of the organic bases (positive mode detection) and 22% of the organic acids (negative mode) occurred in at least 6 of the 11 rainwater samples. Ions corresponding to the m/z of carboxylic acids standards (nonanedioic acid; 1,4-butanedicarboxylic acid; pentanedioic acid; hydroxybutanedioic acid; and butanedioic acid) and to reduced N standards (allylurea; caffeine; imidazole; and N-2-propenylurea) occurred in at least one of the 11 rainwater samples. Total dissolved organic carbon (DOC) estimated from the APESI-MS analysis and measured by standard DOC methods were not statistically different.
authors.affiliation: Institute of Marine and Coastal Sciences, Rutgers/NOAA CMER Program, Rutgers The State University of New Jersey, 71 Dudley Road, New Brunswick, New Jersey 08901-8521, USA. sybil@imcs.rutgers.edu
authors.forename: Sybil P
authors.initials: SP
authors.lastname: Seitzinger
authors.forename: Renée M
authors.initials: RM
authors.lastname: Styles
authors.forename: Ron
authors.initials: R
authors.lastname: Lauck
authors.forename: Monica A
authors.initials: MA
authors.lastname: Mazurek
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D001274:Atmospheric Pressure; D013058:Mass Spectrometry / Q000379:methods*; D009930:Organic Chemicals / Q000032:analysis; D011891:Rain; D012680:Sensitivity and Specificity; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D000393:Air Pollutants; D009930:Organic Chemicals; D014874:Water Pollutants, Chemical