Which of the (Mixed) Halogenated n-Alkanes Are Likely To Be Persistent Organic Pollutants?

Abstract

Short-chain polychlorinated n-alkanes are ubiquitous industrial chemicals widely recognized as persistent organic pollutants. They represent only a small fraction of the 184,600 elemental compositions (C10–25) and the myriad isomers of all possible (mixed) halogenated n-alkanes (PXAs). This study prioritizes the PXAs on the basis of their potential to persist, bioaccumulate, and undergo long-range transport guided by quantitative structure–property relationships (QSPRs), density functional theory (DFT), chemical fate models, and partitioning space. The QSPR results narrow the list to 966 elemental compositions, of which 352 (23 Br, 83 Cl/F, 119 Br/Cl, and 127 Br/F) are likely constituents of substances used as lubricants, plasticizers, and flame retardants. Complementary DFT calculations suggest that an additional 1367 elemental compositions characterized by a greater number of carbon and fluorine atoms but fewer chlorine and bromine atoms may also pose a risk. The results of this study underline the urgent need to identify and monitor these suspected pollutants, most appropriately using mass spectrometry. We estimate that the resolving power required to distinguish ∼74% of the prioritized elemental compositions from the most likely interferents, i.e., chlorinated alkanes, is approximately 60,000 (full width at half-maximum). This indicates that accurate identification of the PXAs is achievable using most high-resolution mass spectrometers.

FindPFΔS: Non-Target Screening for PFAS─Comprehensive Data Mining for MS2 Fragment Mass Differences

“…In general, the list of meaningful mass differences can be easily extended to detect further PFAS or other compounds (e.g., novel ether PFAS, aromatic PFAS, or chlorofluorocarbons, etc.) which have not yet been considered in our work. , …”

Organic geochemistry and mineralogy suggest anthropogenic impact in speleothem chemistry from volcanic show caves of the Galapagos

“…Interestingly, DNA-based analysis of moonmilk and collaroid deposits in both caves showed the presence of Advenella kashmirensis and Phenylobacterium haematophilum bacteria ( Miller et al., 2020b ), which may obtain energy from the degradation of recalcitrant organic compounds. On the other hand, cleaning products, paintings and dissolvents may be the original source of alkyl halogen compounds, which are ubiquitous industrial chemicals widely recognized as persistent organic pollutants ( Li et al., 2021 ). These findings suggest a significant anthropogenic impact in the subterranean environment, inducing changes on speleothem chemistry.…”

Gas Chromatography-(Cyclic) Ion Mobility Mass Spectrometry: A Novel Platform for the Discovery of Unknown Per-/Polyfluoroalkyl Substances

“…43 While the potential source of these contaminants is unknown, their detection is concerning because halocarbon oils are likely replacements to the short-chain chlorinated paraffins (SCCPs) that have been restricted by the Stockholm Convention. Recent environmental fate modeling 44 suggests that hundreds of widely used mixed halogenated n-alkanes, including the Cl/F alkanes, are likely persistent organic pollutants. The first detection of halocarbon oils in the indoor environment underlines the need for further investigation into their environmental occurrence and risk and illustrates the power of our method to reveal novel pollutants.…”