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Fluorotelomer-based polymers (FTPs) are the primary product of the fluorotelomer industry. Here we report on a 376-day study of the degradability of two commercial acrylate-linked FTPs in four saturated soils and in water. Using an exhaustive serial extraction, we report GC/MS and LC/MS/MS results for 50 species including fluorotelomer alcohols and acids, and perfluorocarboxylates. Modeling of seven sampling rounds, each consisting of ≥5 replicate microcosm treatments, for one commercial FTP in one soil yielded half-life estimates of 65–112 years and, when the other commercial FTP and soils were evaluated, the estimated half-lives ranged from 33 to 112 years. Experimental controls, consisting of commercial FTP in water, degraded roughly at the same rate as in soil. A follow-up experiment, with commercial FTP in pH 10 water, degraded roughly 10-fold faster than the circum-neutral control suggesting that commercial FTPs can undergo OH–-mediated hydrolysis. 8:2Fluorotelomer alcohol generated from FTP degradation in soil was more stable than without FTP present suggesting a clathrate guest–host association with the FTP. To our knowledge, these are the only degradability-test results for commercial FTPs that have been generated using exhaustive extraction procedures. They unambiguously show that commercial FTPs, the primary product of the fluorotelomer industry, are a source of fluorotelomer and perfluorinated compounds to the environment.

The optical, redox, and electronic properties of C(8)-heteroaryl-2'-deoxyguanosine (dG) adducts with C(8)-substituents consisting of furyl ((Fur)dG), pyrrolyl ((Pyr)dG), thienyl ((Th)dG), benzofuryl ((Bfur)dG), indolyl ((Ind)dG), and benzothienyl ((Bth)dG) are described. These adducts behave as fluorescent nucleobase probes with emission maxima from 379 to 419 nm and fluorescence quantum yields (Φ(fl)) in the 0.1-0.8 range in water at neutral pH. The probes exhibit quenched fluorescence with increased solvent viscosity and decreased solvent polarity. The (Fur)dG, (Bfur)dG, (Ind)dG, and (Bth)dG derivatives were incorporated into the G(3) position of the 12-mer oligonucleotide 5'-CTCG(1)G(2)CG(3)CCATC-3' that contains the recognition sequence of the NarI Type II restriction endonuclease. This sequence is widely used to study the biological activity (mutagenicity) of C(8)-arylamine-dG adducts with adduct conformation (anti vs syn) playing a critical role in the biological outcome. The modified NarI(X = (Fur)G, (Ind)G, (Bfur)G, or (Bth)G) oligonucleotides were hybridized to the complementary strand containing either C (NarI'(C)) or G (NarI'(G)) opposite the probe. The duplex structures were characterized by UV melting temperature analysis, fluorescence spectroscopy, collisional fluorescence quenching studies, and circular dichroism (CD). The emission of the probes showed sensitivity to the opposing base in the duplex, and suggested the utility of fluorescence spectroscopy to monitor probe conformation.

Fluorotelomer-based acrylate polymers (FTACPs) are a class of side-chain fluorinated polymers used for a variety of commercial applications. The degradation of FTACPs through ester hydrolysis, cleavage of the polymer backbone, or both could serve as a significant source of perfluoroalkyl carboxylates (PFCAs). The biodegradation of FTACPs was evaluated in a soil-plant microcosm over 5.5 months in the absence/presence of wastewater treatment plant (WWTP) biosolids using a unique FTACP determined to be a homopolymer of 8:2 fluorotelomer acrylate (8:2 FTAC). Although structurally different from commercial FTACPs, the unique FTACP possesses 8:2 fluorotelomer side chain appendages bound to the polymer backbone via ester moieties. Liberation and subsequent biodegradation of the 8:2 fluorotelomer appendages was indirectly determined by monitoring for PFCAs of varying chain lengths (C6-C9) and known fluorotelomer intermediates by liquid chromatography tandem mass spectrometry (LC-MS/MS). A FTACP biodegradation half-life range of 8-111 years was inferred from the 8:2 fluorotelomer alcohol (8:2 FTOH) equivalent of the unique FTACP and the increase of degradation products. The progress of FTACP biodegradation was also directly monitored qualitatively using matrix-assisted laser desorption/ionization (MALDI-TOF) time-of-flight mass spectrometry. The combination of indirect and direct analysis indicated that the model FTACP biodegraded predominantly to perfluorooctanoate (PFOA) in soils and at a significantly higher rate in the presence of a plant and WWTP biosolids.

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