Determination of polyoxymethylene (POM) - water partition coefficients for oxy-PAHs and PAHs

Oxygenated polycyclic aromatic hydrocarbons (oxy-PAHs) are a class of ubiquitously occurring pollutants of which little is known. They can be co-emitted with PAHs or formed from PAHs in the environment. The environmental fate and risk of oxy-PAHs are difficult to assess due to a lack of methods to quantify their pore water concentrations. One sampler that can be used to determine freely dissolved concentrations of organic contaminants is polyoxymethylene (POM). In this study, POM - water partition coefficients (K-POM) were determined for 11 oxy-PAHs. K-POM values of 8 PAHs with similar hydrophobicities as the oxy-PAHs were determined for comparison. Results showed that log K-POM values ranged from 2.64 to 4.82 for the PAHs (2-4 rings), similar to previously determined values. LogK(pom) values for investigated oxy-PAHs ranged from 0.96 to 5.36. The addition of carbonylic oxygen on a parent PAH generally lowered K-POM by 0.5 to 1.0 log units, which is attributable to the presence of carbonylic oxygens increasing water solubility. The K-POM values presented here will facilitate simultaneous assessments of freely dissolved water concentrations of oxy-PAHs and PAHs in environmental media. (C) 2014 Elsevier Ltd. All rights reserved.