title: Screening halogenated environmental contaminants in biota based on isotopic pattern and mass defect provided by high resolution mass spectrometry profiling.
abstract: In the present work, we addressed the question of global seeking/screening organohalogenated compounds in a large panel of complex biological matrices, with a particular focus on unknown chemicals that may be considered as potential emerging hazards. A fishing strategy was developed based on untargeted profiling among full scan acquisition datasets provided by high resolution mass spectrometry. Since large datasets arise from such profiling, filtering useful information stands as a central question. In this way, we took advantage of the exact mass differences between Cl and Br isotopes. Indeed, our workflow involved an innovative Visual Basic for Applications script aiming at pairing features according to this mass difference, in order to point out potential organohalogenated clusters, preceded by an automated peak picking step based on the centWave function (xcms package of open access R programming environment). Then, H/Cl-scale mass defect plots were used to visualize the datasets before and after filtering. The filtering script was successfully applied to a dataset generated upon liquid chromatography coupled to ESI(-)-HRMS measurement from one eel muscle extract, allowing for realistic manual investigations of filtered clusters. Starting from 9789 initial obtained features, 1994 features were paired in 589 clusters. Hexabromocyclododecane, chlorinated paraffin series and various other compounds have been identified or tentatively identified, allowing thus broad screening of organohalogenated compounds in this extract. Although realistic, manual review of paired clusters remains time consuming and much effort should be devoted to automation.
authors: LUNAM Université, ONIRIS, Laboratoire d'Etude des Résidus et Contaminants dans les Aliments (LABERCA), Nantes, F-44307, France. Electronic address: laberca@oniris-nantes.fr.
authors: Ronan
authors: R
authors: Cariou
authors: LUNAM Université, ONIRIS, Laboratoire d'Etude des Résidus et Contaminants dans les Aliments (LABERCA), Nantes, F-44307, France.
authors: Elsa
authors: E
authors: Omer
authors: LUNAM Université, ONIRIS, Laboratoire d'Etude des Résidus et Contaminants dans les Aliments (LABERCA), Nantes, F-44307, France.
authors: Alexis
authors: A
authors: Léon
authors: LUNAM Université, ONIRIS, Laboratoire d'Etude des Résidus et Contaminants dans les Aliments (LABERCA), Nantes, F-44307, France.
authors: Gaud
authors: G
authors: Dervilly-Pinel
authors: LUNAM Université, ONIRIS, Laboratoire d'Etude des Résidus et Contaminants dans les Aliments (LABERCA), Nantes, F-44307, France.
authors: Bruno
authors: B
authors: Le Bizec
mesh_terms: D004784:Environmental Monitoring; D004785:Environmental Pollutants / Q000032:analysis*; D006846:Hydrocarbons, Halogenated / Q000032:analysis*; D007553:Isotope Labeling; D013058:Mass Spectrometry
chemical_list: D004785:Environmental Pollutants; D006846:Hydrocarbons, Halogenated
keywords: Chemical risk assessment; Chlorinated paraffins; Emerging contaminants; Fit-for-purpose data processing; HRMS screening; Visual Basic Script