Format

Send to

Choose Destination
See comment in PubMed Commons below
Environ Toxicol Chem. 2008 Jun;27(6):1244-9. doi: 10.1897/07-486. Epub 2008 Jan 25.

Vapor pressures and thermodynamics of oxygen-containing polycyclic aromatic hydrocarbons measured using Knudsen effusion.

Author information

1
Division of Engineering, Brown University, Providence, RI 02912, USA. jillian_goldfarb@brown.edu

Abstract

Polycyclic aromatic hydrocarbons (PAHs) and their oxygenated derivatives (OPAHs) are ubiquitous environmental pollutants resulting from the incomplete combustion of coal and fossil fuels. Their vapor pressures are key thermodynamic data essential for modeling fate and transport within the environment. The present study involved nine PAHs containing oxygen heteroatoms, including aldehyde, carboxyl, and nitro groups, specifically 2-nitrofluorene, 9-fluorenecarboxylic acid, 2-fluorenecarboxaldehyde, 2-anthracenecarboxylic acid, 9-anthracenecarboxylic acid, 9-anthraldehyde, 1-nitropyrene, 1-pyrenecarboxaldehyde, and 1-bromo-2-naphthoic acid. The vapor pressures of these compounds, with molecular weights ranging from 194 to 251 g/mol, were measured using the isothermal Knudsen effusion technique in the temperature range of 329 to 421 K. The corresponding enthalpies of sublimation, calculated via the Clausius-Clapeyron equation, are compared to parent, nonoxygenated PAH compound data to determine the effect of the addition of these oxygen-containing heteroatoms. As expected, the addition of -CHO, -COOH, and -NO(2) groups onto these PAHs increases the enthalpy of sublimation and decreases the vapor pressure as compared to the parent PAH; the position of substitution also plays a significant role in determining the vapor pressure of these OPAHs.

PMID:
18220445
PMCID:
PMC3642867
DOI:
10.1897/07-486
[Indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments

    Supplemental Content

    Full text links

    Icon for Wiley Icon for PubMed Central
    Loading ...
    Support Center