title: Microbial transformation of 8:2 fluorotelomer acrylate and methacrylate in aerobic soils.
abstract: Biotransformation of fluorotelomer (FT) compounds, such as 8:2 FT alcohol (FTOH) is now recognized to be a source of perfluorooctanoic acid (PFOA) as well as other perfluoroalkyl acids. In this study, microbially mediated hydrolysis of FT industrial intermediates 8:2 FT acrylate (8:2 FTAC) and 8:2 FT methacrylate (8:2 FTMAC) was evaluated in aerobic soils for up to 105d. At designated times, triplicate microcosms were sacrificed by sampling the headspace for volatile FTOHs followed by sequential extraction of soil for the parent monomers as well as transient and terminal degradation products. Both FTAC and FTMAC were hydrolyzed at the ester linkage as evidenced by 8:2 FTOH production. 8:2 FTAC and FTMAC degraded rapidly with half-lives ⩽5d and 15d, respectively. Maximum 8:2 FTOH levels were 6-13mol% within 3-6d. Consistent with the known biotransformation pathway of 8:2 FTOH, FT carboxylic acids and perfluoroalkyl carboxylic acids were subsequently generated including up to 10.3mol% of PFOA (105d). A total mass balance (parent plus metabolites) of 50-75mol% was observed on the last sampling day. 7:2 sFTOH, a direct precursor to PFOA, unexpectedly increased throughout the incubation period. The likely, but unconfirmed, concomitant production of acrylic acids was proposed as altering expected degradation patterns. Biotransformation of 8:2 FTAC, 8:2 FTMAC, and previously reported 8:2 FT-stearate for the same soils revealed the effect of the non-fluorinated terminus group linked to the FT chain on the electronic differences that affect microbially-mediated ester cleavage rates.
authors.affiliation: Department of Agronomy, Purdue University, West Lafayette, IN 47907-2054, United States.
authors.forename: Laurel A
authors.initials: LA
authors.lastname: Royer
authors.affiliation: Department of Agronomy, Purdue University, West Lafayette, IN 47907-2054, United States. Electronic address: lslee@purdue.edu.
authors.forename: Linda S
authors.initials: LS
authors.lastname: Lee
authors.affiliation: DuPont Haskell Global Centers for Health and Environmental Sciences, Newark, DE 19714, United States.
authors.forename: Mark H
authors.initials: MH
authors.lastname: Russell
authors.affiliation: Division of Environmental and Ecological Engineering, School of Civil Engineering, Purdue University, West Lafayette, IN 47907-2051, United States.
authors.forename: Loring F
authors.initials: LF
authors.lastname: Nies
authors.affiliation: Department of Agronomy, Purdue University, West Lafayette, IN 47907-2054, United States.
authors.forename: Ronald F
authors.initials: RF
authors.lastname: Turco
mesh_terms: D000179:Acrylates / Q000032:analysis* / Q000737:chemistry; D000332:Aerobiosis; D000438:Alcohols / Q000737:chemistry; D001673:Biodegradation, Environmental; D001711:Biotransformation; D002210:Caprylates / Q000032:analysis / Q000737:chemistry; D002264:Carboxylic Acids / Q000032:analysis / Q000737:chemistry; D004784:Environmental Monitoring / Q000379:methods*; D005465:Fluorocarbon Polymers; D005466:Fluorocarbons / Q000032:analysis / Q000737:chemistry; D006845:Hydrocarbons, Fluorinated / Q000032:analysis* / Q000737:chemistry; D008689:Methacrylates / Q000032:analysis* / Q000737:chemistry; D008962:Models, Theoretical; D015394:Molecular Structure; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000032:analysis* / Q000737:chemistry
chemical_list: D000179:Acrylates; D000438:Alcohols; D002210:Caprylates; D002264:Carboxylic Acids; D005465:Fluorocarbon Polymers; D005466:Fluorocarbons; D006845:Hydrocarbons, Fluorinated; D008689:Methacrylates; D012989:Soil Pollutants; C540553:fluorotelomer acrylate polymers; C023036:perfluorooctanoic acid
keywords: Biotransformation; Ester cleavage; PFOA; Perfluorinated compounds; Perfluoroalkyl carboxylic acids