posted on 2024-03-13, 22:03authored byThomas
J. McGrath, Julien Saint-Vanne, Sébastien Hutinet, Walter Vetter, Giulia Poma, Yukiko Fujii, Robin E. Dodson, Boris Johnson-Restrepo, Dudsadee Muenhor, Bruno Le Bizec, Gaud Dervilly, Adrian Covaci, Ronan Cariou
Bromochloro
alkanes (BCAs) have been manufactured for use as flame
retardants for decades, and preliminary environmental risk screening
suggests they are likely to behave similarly to polychlorinated alkanes
(PCAs), subclasses of which are restricted as Stockholm Convention
Persistent Organic Pollutants (POPs). BCAs have rarely been studied
in the environment, although some evidence suggests they may migrate
from treated-consumer materials into indoor dust, resulting in human
exposure via inadvertent ingestion. In this study, BCA-C14 mixture standards were synthesized and used to validate an analytical
method. This method relies on chloride-enhanced liquid chromatography–electrospray
ionization–Orbitrap-high resolution mass spectrometry (LC-ESI-Orbitrap-HRMS)
and a novel CP-Seeker integration software package for homologue detection
and integration. Dust sample preparation via ultrasonic extraction,
acidified silica cleanup, and fractionation on neutral silica cartridges
was found to be suitable for BCAs, with absolute recovery of individual
homologues averaging 66 to 78% and coefficients of variation ≤10%
in replicated spiking experiments (n = 3). In addition,
a total of 59 indoor dust samples from six countries, including Australia
(n = 10), Belgium (n = 10), Colombia
(n = 10), Japan (n = 10), Thailand
(n = 10), and the United States of America (n = 9), were analyzed for BCAs. BCAs were detected in seven
samples from the U.S.A., with carbon chain lengths of C8, C10, C12, C14, C16,
C18, C24 to C28, C30 and
C31 observed overall, though not detected in samples from
any other countries. Bromine numbers of detected homologues in the
indoor dust samples ranged Br1–4 as well as Br7, while chlorine numbers ranged Cl2–11.
BCA-C18 was the most frequently detected, observed in each
of the U.S.A. samples, while the most prevalent degrees of halogenation
were homologues of Br2 and Cl4–5. Broad
estimations of BCA concentrations in the dust samples indicated that
levels may approach those of other flame retardants in at least some
instances. These findings suggest that development of quantification
strategies and further investigation of environmental occurrence and
health implications are needed.