| Title: | "Ambient gas/particle partitioning. 1. Sorption mechanisms of apolar, polar, and ionizable organic compounds" |
| Author(s): | Arp HP; Schwarzenbach RP; Goss KU; |
| Address: | "Institute of Biogeochemistry and Pollutant Dynamics, ETH-Zurich, Universitatsstrasse 16, 8092 Zurich, Switzerland. hpa@ngi.no" |
| ISSN/ISBN: | 0013-936X (Print) 0013-936X (Linking) |
| Abstract: | "There remain several ambiguities in the literature regarding the dominating sorption mechanisms involved in gas/particle partitioning, particularly for polar and ionizable compounds. The various hypothetical mechanisms would depend differently on relative humidity (RH) and the presence of various aerosol components. Thus, in order to resolve these ambiguities, here we measured the RH-dependency of gas/particle partitioning constants, K(ip), for four diverse aerosol samples and a large set of chemicals covering apolar, polar, and ionizable organic compounds. In addition, we also removed the water-soluble components from two ambient particle samples to study how their presence influences sorption behavior. The measured K(ip) values collectively indicate that a dual-phase sorption mechanism is occurring, in which organic compounds partition into a RH-independent water-insoluble organic matter phase and additionally into a RH-dependent mixed-aqueous phase. All K(ip) values could be successfully fitted to a RH-dependent dual-phase sorption model. The trends in K(ip) data further support findings that the sorption behavior of ambient aerosol samples is different from raw mineral surfaces and soot" |
| Keywords: | Adsorption Air Pollutants/*chemistry *Environmental Monitoring Gases/*chemistry Humidity Ions/chemistry Minerals/chemistry Organic Chemicals/*chemistry Particle Size Particulate Matter/*chemistry Solubility Soot/chemistry Volatilization Water/chemistry; |
| Notes: | "MedlineArp, Hans Peter H Schwarzenbach, Rene P Goss, Kai-Uwe eng 2008/08/30 Environ Sci Technol. 2008 Aug 1; 42(15):5541-7. doi: 10.1021/es703094u" |
