Resolving Polychlorinated Biphenyl Congener Coelutions: A Case Study in Environmental Air Samples

Reported analytical data for polychlorinated biphenyls
(PCBs),
as well as other chemical classes, often include unresolved coelutions,
which inhibits an accurate quantitative determination of individual
compounds. Unresolved congener coelutions add uncertainty in the interpretation
of PCB exposures and associated health risks. To address this important
data gap, we developed a quantitative approach to resolving PCB coelutions.
In commonly used analytical methods, PCB congeners may coelute within
the same analytical peak, with peaks typically containing 2–3
congeners. Importantly, the presence and composition of PCB congener
coelutions varies across analytical and experimental methods. We leveraged
this variation, creating a data set of 151 air studies from existing
literature that reported measures for multiple individual PCB congeners.
We then developed and applied a novel modeling framework that generates
congener proportion estimates for each individual congener within
172 PCB coelution groupings identified in our review. This approach
for resolving coelutions will be useful in a variety of applications,
including exposure assessments and estimates of flux. More broadly,
these data will be imperative for PCB risk and hazard assessments
designed to address the potential differences in impacts to human
health and the environment based on the individual congeners present
in PCB mixtures.