摘要：AbstractSince 2001, twenty-eight halogenated groups of persistent organic pollutants (POPs) have been banned or restricted by the Stockholm Convention. Identifying new POPs among the hundreds of thousands of anthropogenic chemicals is a major challenge that is increasingly being met by state-of-the-art mass spectrometry (MS). The first step to identification of a contaminant molecule (M) is the determination of the type and number of its constituent elements, viz. itselemental composition, from mass-to-charge (m/z) measurements and ratios of isotopic peaks (M + 1, M + 2 etc.). Not every combination of elements is possible. Boundaries exist incompositional spacethat divides feasible and improbable compositions as well as different chemical classes. This study explores the compositional space boundaries of persistent and bioaccumulative organics. A set of ~305,134 compounds (PubChem) was used to visualize the compositional space occupied by F, Cl, and Br compounds, as defined bym/zand isotope ratios. Persistent bioaccumulative organics, identified byin silicoscreening of 22,049 commercial chemicals, reside in more constrained regions characterized by a higher degree of halogenation. In contrast, boundaries surrounding non-halogenated chemicals could not be defined. Finally, a script tool (R code) was developed to select potential POPs from high resolution MS data. When applied to household dust (SRM 2585), this approach resulted in the discovery of previously unknown chlorofluoro flame retardants.Graphical abstractDisplay OmittedHighlights•Elemental composition determination is the first step to identifying a contaminant.•Boundaries incompositional spaceenclose persistent organic pollutants (POPs).•~305,134 compounds (PubChem) were used to visualize the space occupied POPs.•A script tool was developed to select potential POPs from high resolution MS data.•Unknown Cl/F-flame retardants were identified in house dust.
关键词：Persistent organic pollutants;Nontargeted screening;Environmental mass spectrometry;Flame retardants;Chemical space
