Resolving unknown isomers of emerging per- and polyfluoroalkyl substances (PFASs) in environmental samples using COSMO-RS-derived retention factor and mass fragmentation patterns

JOURNAL OF HAZARDOUS MATERIALS

卷:402

Article

Guardian, Mary Grace E.¹  Antle, Jonathan P.²  Vexelman, Paul A.²  Aga, Diana S.¹  Simpson, Scott M.² 

[1] SUNY Buffalo, Dept Chem, Buffalo, NY 14260 USA

[2] Bonaventure Univ, Dept Chem, St Bonaventure, NY 14778 USA

关键词: Perfluorooctanoic acid (PFOA);    Perfluorooctane sulfonate (PFOS);    High resolution mass spectrometry;    Suspect screening;    PFASs isomers;   

DOI  :  10.1016/j.jhazmat.2020.123478

来源: Elsevier

【 摘 要 】

Chromatographic retention factors (k) and mass spectral fragmentation patterns of perand poly-fluoroalkyl substances (PFASs) were determined using the optimized parameters in liquid chromatography with tandem high-resolution mass spectrometry (LC-HRMS) analysis. Characteristic fragment ions obtained at various collision energies (MS2 fragmentation) were used to determine the structures of newly discovered (emerging) PFASs detected from industrial effluent and surface water samples. Moreover, COnductor-like Screening MOdel for Realistic Solvents (COSMO-RS) derived octanol-water partition coefficients (K-ow), along with mean isotropic polarizabilities calculated from Density Functional Theory (DFT), of known PFASs were plotted against their experimental k values (k(exp)) to obtain a multivariable regression model that can be used to predict k values of unknown PFASs. The k values of different structural isomers of unknown PFASs were calculated and compared to k(exp). The predicted k value for the isomer that matches the MS2 fragmentation observed was found to be within 4.2 % of k(exp). This study demonstrates the applicability of an approach that combines the observed MS2 fragmentation patterns and k values, together with computationally-derived log K-ow and polarizabilities, in assigning the structures of unknown PFASs at environmentally relevant conditions when no reference standards are available.

【 授权许可】

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