Nontargeted LC/ESI-HRMS Detection of Polyhalogenated Compounds in Marine Mammals Stranded on French Atlantic Coasts

To
date, nontargeted analysis (NTA) of halogenated organic compounds
in biota has mostly been performed using GC/MS-based instruments.
We intended to broaden the spectrum of physicochemical properties
of amenable substances by taking advantage of liquid chromatography–high-resolution
mass spectrometry coupling paired with an electrospray ionization
source. Thus, a NTA strategy was applied to a set of 12 blubber samples
belonging to five marine mammal sentinel species stranded on the French
Atlantic coasts. It involved specific postacquisition data interpretation
using open-source software HaloSeeker 1.0 for annotating chemical
formulas. A total of 135 distinct unequivocal molecular formulas were
assigned to 466 polyhalogenated ion clusters of interest. The most
intense representative ions were identified as bioaccumulative heptachloro-1,2′-bipyrrole
(Cl7-BP), α-hexabromocyclododecane, and (1R,2S,4R,5R,1′E)-2-bromo-1-bromomethyl-1,4-dichloro-5-(2′-chloroethenyl)-5-methylcyclohexane
(MHC-1) in the weight range of micrograms per gram of lipids. To the
best of our knowledge, this is the first time that Cl7-BP,
the most intense signal observed, is reported in biota. A dozen other
compound families will require further in-depth work to gain structural
information.