US EPA

4663144 

Journal Article 

Particle/Gas Partitioning of Phthalates to Organic and Inorganic Airborne Particles in the Indoor Environment 

Wu, Y; Eichler, CMA; Cao, J; Benning, J; Olson, A; Chen, S; Liu, C; Vejerano, EP; Marr, LC; Little, JC 

2018 

1 

Environmental Science & Technology
ISSN: 0013-936X
EISSN: 1520-5851 

AMER CHEMICAL SOC 

WASHINGTON 

52 

6 

3583-3590 

English 

29446939 

10.1021/acs.est.7b05982 

WOS:000428219900033 

http://pubs.acs.org/doi/10.1021/acs.est.7b05982
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The particle/gas partition coefficient Kp is an important parameter affecting the fate and transport of indoor semivolatile organic compounds (SVOCs) and resulting human exposure. Unfortunately, experimental measurements of Kp exist almost exclusively for atmospheric polycyclic aromatic hydrocarbons, with very few studies focusing on SVOCs that occur in indoor environments. A specially designed tube chamber operating in the laminar flow regime was developed to measure Kp of the plasticizer di-2-ethylhexyl phthalate (DEHP) for one inorganic (ammonium sulfate) and two organic (oleic acid and squalane) particles. The values of Kp for the organic particles (0.23 ± 0.13 m3/μg for oleic acid and 0.11 ± 0.10 m3/μg for squalane) are an order of magnitude higher than those for the inorganic particles (0.011 ± 0.004 m3/μg), suggesting that the process by which the particles accumulate SVOCs is different. A mechanistic model based on the experimental design reveals that the presence of the particles increases the gas-phase concentration gradient in the boundary layer, resulting in enhanced mass transfer from the emission source into the air. This novel approach provides new insight into experimental designs for rapid Kp measurement and a sound basis for investigating particle-mediated mass transfer of SVOCs. 

article; ammonium sulfate; environmental science; experimental design; laminar flow; mass transfer; mechanistic models; oleic acid; phthalates; plasticizers; polycyclic aromatic hydrocarbons; volatile organic compounds