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), αhexabromocyclododecane, 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.