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

Abstract

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.