Unbiased passive sampling of all polychlorinated biphenyls congeners from air

Abstract

The desire to quantify the presence of a wide range of polychlorinated biphenyls (PCBs) in air is driven both by an interest in the sources and fate of unintentionally produced congeners and in quantifying human inhalation exposure to volatile PCBs. The wide volatility range can introduce bias when sampling the entire suite of PCBs. Here, we present the result of a field calibration experiment that demonstrates that even the most volatile PCBs maintain linear uptake in a passive air sampler using XAD-resin as the sorbent (XAD-PAS). Empirically derived sampling rates (SRs) for 66 congeners decrease with the number of chlorines and, within a homologue, increase with the number of chlorines in the ortho-position. The large seasonal temperature range at the site of the calibration allowed for an estimation of the temperature dependence of the SRs. The effects of chlorine substitution and temperature can be expressed quantitatively through a regression relating the SR to the sorption constant to XAD from the gas phase. As a result, it is possible to estimate SRs for all congeners at any deployment temperature. The XAD-PAS is well suited for unbiased sampling of gaseous PCBs in a wide variety of settings.