A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Chemical nature and molecular weight distribution of the water-soluble fine and ultrafine PM fractions collected in a rural environment
Abstract PM1–2.5, PM0.1–1, and PM<0.1 water-soluble organic carbon (WSOC) fractions of aerosol samples collected during summer and fall 2009 were analyzed by UV/VIS spectroscopy and electrospray ionization–mass spectrometry (ESI/MS). The focus of this study was to compare optical properties, chemical nature, and molecular weight distribution in samples extracted from different size fractions and collected during different seasons (fall vs. summer). Diurnal patterns were also investigated. An increase in absorptivity, aromaticity, and average molecular weight (AMW) in all size fractions found in the fall samples indicates different formation processes for the organic carbon between the summer and fall periods. The fall ultrafine fraction (PM<0.1) demonstrated characteristics different from the other two PM size fractions and more similar to aquatic fulvic acids. It had the highest HULIS/WSOC ratio, molar absorptivity, and AMWs up to about 700 Da when analyzed by the UV/VIS method and about 475 Da by the ESI/MS. Higher concentrations of organosulfate (OS) compounds and polycarboxylic acids were detected in the summer samples while organonitrate (ON) compounds and monocarboxylic acids were higher in the fall samples.
Highlights ► Water-soluble organic carbon (WSOC) in different size PM fractions. ► WSOC in the PM1–2.5 fraction ranged from 37% to 47%. ► PM<0.1 contribute the least to the WSOC content (19%–31%). ► Average molecular weights ranged from 560 Da to 700 Da. ► Tandem MS found carboxylic, polycarboxylic acids, organosulfates, and -nitrates.
Chemical nature and molecular weight distribution of the water-soluble fine and ultrafine PM fractions collected in a rural environment
Abstract PM1–2.5, PM0.1–1, and PM<0.1 water-soluble organic carbon (WSOC) fractions of aerosol samples collected during summer and fall 2009 were analyzed by UV/VIS spectroscopy and electrospray ionization–mass spectrometry (ESI/MS). The focus of this study was to compare optical properties, chemical nature, and molecular weight distribution in samples extracted from different size fractions and collected during different seasons (fall vs. summer). Diurnal patterns were also investigated. An increase in absorptivity, aromaticity, and average molecular weight (AMW) in all size fractions found in the fall samples indicates different formation processes for the organic carbon between the summer and fall periods. The fall ultrafine fraction (PM<0.1) demonstrated characteristics different from the other two PM size fractions and more similar to aquatic fulvic acids. It had the highest HULIS/WSOC ratio, molar absorptivity, and AMWs up to about 700 Da when analyzed by the UV/VIS method and about 475 Da by the ESI/MS. Higher concentrations of organosulfate (OS) compounds and polycarboxylic acids were detected in the summer samples while organonitrate (ON) compounds and monocarboxylic acids were higher in the fall samples.
Highlights ► Water-soluble organic carbon (WSOC) in different size PM fractions. ► WSOC in the PM1–2.5 fraction ranged from 37% to 47%. ► PM<0.1 contribute the least to the WSOC content (19%–31%). ► Average molecular weights ranged from 560 Da to 700 Da. ► Tandem MS found carboxylic, polycarboxylic acids, organosulfates, and -nitrates.
Chemical nature and molecular weight distribution of the water-soluble fine and ultrafine PM fractions collected in a rural environment
Pavlovic, J. (author) / Hopke, P.K. (author)
Atmospheric Environment ; 59 ; 264-271
2012-04-27
8 pages
Article (Journal)
Electronic Resource
English
Molecular weight distribution of soluble microbial products in biological systems
| British Library Conference Proceedings | 1996
Molecular weight distribution of soluble microbial products in biological systems
| British Library Conference Proceedings | 1996