Fluorotelomer alcohol biodegradation yields poly- and perfluorinated acids

Area of Science:

• Environmental Chemistry
• Microbiology
• Environmental Science

Background:

• Environmentally persistent perfluorinated acids (PFCAs), including perfluorooctanoic acid (PFOA), are detected in biota.
• Fluorinated telomer alcohols (FTOHs) are suspected precursors to PFCAs through environmental transformation.
• Understanding FTOH biodegradation is crucial for identifying PFCA sources.

Purpose of the Study:

• To investigate the aerobic biodegradation of 8:2 telomer alcohol (8:2 FTOH).
• To identify metabolites formed during 8:2 FTOH degradation.
• To assess the role of biotic transformation in PFCA formation from FTOHs.

Main Methods:

• Aerobic biodegradation of 8:2 FTOH using a mixed microbial system.
• Monitoring degradation via gas chromatography with an electron capture detector (GC/ECD).
• Identification of volatile and nonvolatile metabolites using gas chromatography/mass spectrometry (GC/MS) and liquid chromatography/tandem mass spectrometry (LC/MS/MS).

Main Results:

• 8:2 FTOH exhibited a rapid initial half-life of approximately 0.2 days mg(-1) protein.
• Telomer acids and perfluorooctanoic acid (PFOA) were identified as key metabolites.
• The unsaturated telomer acid was the predominant metabolite, formed via oxidation and beta-oxidation pathways.

Conclusions:

• Telomer alcohols, specifically 8:2 FTOH, serve as potential biotic sources for the formation of PFCAs.
• Biological transformation is a significant degradation pathway for FTOHs in aquatic environments.
• This microbial process contributes to the environmental presence of persistent PFCAs like PFOA.