Suspect Screening, Prioritization, and Confirmation of Environmental Chemicals in Maternal-Newborn Pairs from San Francisco

Our proof-of-concept study develops a suspect screening workflow
to identify and prioritize potentially ubiquitous chemical exposures
in matched maternal/cord blood samples, a critical period of development
for future health risks. We applied liquid chromatography–quadrupole
time-of-flight tandem mass spectrometry (LC-QTOF/MS) to perform suspect
screening for ∼3500 industrial chemicals on pilot data from
30 paired maternal and cord serum samples (n = 60).
We matched 662 suspect features in positive ionization mode and 788
in negative ionization mode (557 unique formulas overall) to compounds
in our database, and selected 208 of these for fragmentation analysis
based on detection frequency, correlation in feature intensity between
maternal and cord samples, and peak area differences by demographic
characteristics. We tentatively identified 73 suspects through fragmentation
spectra matching and confirmed 17 chemical features (15 unique compounds)
using analytical standards. We tentatively identified 55 compounds
not previously reported in the literature, the majority which have
limited to no information about their sources or uses. Examples include
(i) 1-(1-acetyl-2,2,6,6-tetramethylpiperidin-4-yl)-3-dodecylpyrrolidine-2,5-dione
(known high production volume chemical) (ii) methyl perfluoroundecanoate
and 2-perfluorooctyl ethanoic acid (two PFAS compounds); and (iii)
Sumilizer GA 80 (plasticizer). Thus, our workflow demonstrates an
approach to evaluating the chemical exposome to identify and prioritize
chemical exposures during a critical period of development.