Unbiased Passive Sampling of All Polychlorinated Biphenyls Congeners from Air

The desire to quantify the presence of a wide range ofpolychlorinatedbiphenyls (PCBs) in air is driven both by an interest in the sourcesand fate of unintentionally produced congeners and in quantifyinghuman inhalation exposure to volatile PCBs. The wide volatility rangecan introduce bias when sampling the entire suite of PCBs. Here, wepresent the result of a field calibration experiment that demonstratesthat even the most volatile PCBs maintain linear uptake in a passiveair sampler using XAD-resin as the sorbent (XAD-PAS). Empiricallyderived sampling rates (SRs) for 66 congeners decreasewith the number of chlorines and, within a homologue, increase withthe number of chlorines in the ortho-position. The large seasonaltemperature range at the site of the calibration allowed for an estimationof the temperature dependence of the SRs. The effectsof chlorine substitution and temperature can be expressed quantitativelythrough a regression relating the SR to the sorptionconstant to XAD from the gas phase. As a result, it is possible toestimate SRs for all congeners at any deploymenttemperature. The XAD-PAS is well suited for unbiased sampling of gaseousPCBs in a wide variety of settings.

Automated summary

This study demonstrates that even the most volatile PCBs can maintain linear uptake in a passive air sampler using XAD-resin as the sorbent (XAD-PAS). The sampling rates for 66 congeners decrease with the number of chlorines and increase within a homologue with the number of chlorines in the ortho-position. By quantifying the effects of chlorine substitution and temperature on sampling rates, it is possible to estimate the sampling rates for all congeners at any deployment temperature. The XAD-PAS is suitable for unbiased sampling of gaseous PCBs in various settings.