Characterization of polycyclic aromatic compounds in historically contaminated soil by targeted and non-targeted chemical analysis combined with in vitro bioassay. (15th November 2021)

• Record Type: Journal Article
• Authors: Titaley, Ivan A.; Lam, Monika M.; Bülow, Rebecca; Enell, Anja; Wiberg, Karin; Larsson, Maria
• Is Part Of: Environmental pollution. Volume 289(2021)
• Publication Date: 2021-11-15
• Subjects: Polycyclic aromatic compounds -- Orbitrap™ GC-MS -- Full-scan screening -- Non-targeted analysis -- Aryl hydrocarbon receptor-activity -- Bio-TEQ; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2021.117910
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: Soil samples from a contaminated site in Sweden were analyzed to identify the presence of 78 polycyclic aromatic compounds (PACs) using gas chromatography coupled with mass spectrometry (GC-MS). The target analysis revealed large contributions not only from polycyclic aromatic hydrocarbons (PAHs), but also from alkylated- and oxygenated-PAHs (alkyl- and oxy-PAHs, respectively), and N-heterocyclics (NPACs). PAC profiles indicated primarily pyrogenic sources, although contribution of petrogenic sources was also observed in one sample as indicated by a high ratio of alkylated naphthalene compared to naphthalene. The aryl hydrocarbon receptor (AhR)-activity of the soil extracts was assessed using the H4IIe-pGudluc 1.1 cells bioassay. When compared with the calculated total AhR-activity of the PACs in the target list, 35–97% of the observed bioassay activity could be explained by 62 PACs with relative potency factors (REPs). The samples were further screened using GC coupled with Orbitrap™ high resolution MS (GC-HRMS) to investigate the presence of other PACs that could potentially contribute to the AhR-activity of the extracts. 114 unique candidate compounds were tentatively identified and divided into four groups based on their AhR-activity and environmental occurrence. Twelve substances satisfied all the criteria, and these compounds are suggested to be included in regular screening in future studies, although their identities were not confirmed by standards in this study. High unexplained bio-TEQ fractions in three of the samples may be explained by tentatively identified compounds ( n = 35) with high potential of being toxic. This study demonstrates the benefit of combining targeted and non-targeted chemical analysis with bioassay analysis to assess the diversity and effects of PACs at contaminated sites. The applied prioritization strategy revealed a number of tentatively identified compounds, which likely contributed to the overall bioactivity of the soil extracts. Graphical abstract: Image 1 Highlights: PAHs, alkyl- and oxy-PAHs, and N-, S-, OPACs were measured in soil samples. Chem-TEQ calculations were able to explain 35–97% of bio-TEQs in the extracts. Non-targeted analysis with GC-HRMS tentatively identified 114 candidate compounds. 12 tentatively identified compounds are AhR-active and have been found in soil. More PACs and transformation products need to be studied to fully assess bio-TEQ.