Direct measurements of polyurethane foam (PUF) - air partitioning coefficients for chemicals of emerging concern capable of equilibrating in PUF disk samplers

摘要

Organophosphate esters (OPEs), novel flame retardants (NFRs) and organochlorine pesticides (OCPs) are volatile to semi-volatile chemicals and therefore susceptible to approach equilibrium during typical deployments of polyurethane foam (PUF) disk passive air samplers. A generator column approach was used to measure the PUF-air partitioning coefficient (KPUF-air) for these targeted chemicals. KPUF-air values are required for these chemicals to estimate sampled equivalent air volumes, which vary substantially with temperature. Log KPUF-air measurements were made at temperatures ranging from +6 to +35 degrees C and resulting values ranged from 5.14 to 7.77. Enthalpies of phase change for PUF to air (Delta HPUF-air, kJ/mol) ranged from 51.3 to 98.9. Two relationships of log KPUF-air versus log Koctanol-air (K-OA) were derived, grouping OPEs and NFRs separately. The relationship for NFRs was in fair agreement (within about 0.6 log units) to a long-standing relationship by Shoeib and Harner (since 2002) for polychlorinated biphenyls (PCBs). However, the estimated values using Shoeib-Harner relationship substantially underestimates KpuF-air for the OPEs than directly measured values (by about an order of magnitude). These findings highlight the importance of the direct measurements of KPUF-air for emerging classes of chemicals whose concentrations are at risk of equilibrating in PUF disk samplers. Crown Copyright (C) 2019 Published by Elsevier Ltd.