Novel Polyfluorinated Compounds Identified Using High Resolution Mass Spectrometry Downstream of Manufacturing Facilities near Decatur, Alabama

Concern over persistence, bioaccumulation, and toxicity has led to international regulation and phase-outs of certain perfluorinated compounds and little is known about their replacement products. High resolution mass spectrometry was used to investigate the occurrence and identity of replacement fluorinated compounds in surface water and sediment of the Tennessee River near Decatur, Alabama. Analysis of legacy Per- and polyfluoroalkyl substances (PFASs) revealed a marked increase in concentrations downstream of manufacturing facilities, with the most abundant compounds being perfluorooctanesulfonate (PFOS), perfluorobutanesulfonate (PFBS), and perfluorooctanoic acid (PFOA) as high as 220 ng L^–1, 160 ng L^–1, and 120 ng L^–1, respectively. A series of nine polyfluorinated carboxylic acids was discovered, each differing by CF₂CH₂. These acids are likely products or byproducts of a manufacturing process that uses 1,1-difluoroethene, which is registered to a manufacturing facility in the area. Two other predominant compounds discovered have structures consistent with perfluorobutanesulfonate and perfluoroheptanoic acid but have a single hydrogen substituted for a fluorine someplace in their structure. A polyfluoroalkyl sulfate with differing mixes of hydrogen and fluorine substitution was also observed. <i>N</i>-methyl perfluorobutane sulfonamidoacetic acid (MeFBSAA) was observed at high concentrations and several other perfluorobutane sulfonamido substances were present as well

Longitudinal concentrations of PFAAs during the dry season.

<p>Box plot indicate minimum and maximum (bars), 25 quartile (white box), median (horizontal line), and 75 quartile (black box). Significantly different concentrations (ANOVA, <i>p</i><0.05) among sites are shown with different letters.</p

Total concentrations (ng/L) and percent of total PFAAs determined in the water column during the wet season at various longitudinal points in Sweetwater branch stream.

<p>Total concentrations (ng/L) and percent of total PFAAs determined in the water column during the wet season at various longitudinal points in Sweetwater branch stream.</p

Organic Mater, texture, pH, and iron at three depths in sediments from Sweetwater branch canal.

<p>Organic Mater, texture, pH, and iron at three depths in sediments from Sweetwater branch canal.</p

Water and sediment sampling points along Sweetwater branch canal.

<p>Water and sediment sampling points along Sweetwater branch canal.</p

Geographic coordinates for each of the sampling points in this study.

<p>Geographic coordinates for each of the sampling points in this study.</p

Longitudinal concentrations of PFAAs during the wet season.

<p>Box plot indicate minimum and maximum (bars), 225 quartile (white box), median (horizontal line), and 75 quartile (black box). No statistical differences were found for collections during the wet season.</p

Using the US EPA’s CompTox Chemistry Dashboard to support identification and screening of emerging contaminants in the environment

Presentation to NC State Lab Group April 201

Using the US EPA’s CompTox Chemistry Dashboard to support identification and screening of emerging contaminants in the environment

Presentation at American Chemical Society Meeting April 201

Legacy and Emerging Perfluoroalkyl Substances Are Important Drinking Water Contaminants in the Cape Fear River Watershed of North Carolina

Long-chain per- and polyfluoroalkyl substances (PFASs) are being replaced by short-chain PFASs and fluorinated alternatives. For ten legacy PFASs and seven recently discovered perfluoroalkyl ether carboxylic acids (PFECAs), we report (1) their occurrence in the Cape Fear River (CFR) watershed, (2) their fate in water treatment processes, and (3) their adsorbability on powdered activated carbon (PAC). In the headwater region of the CFR basin, PFECAs were not detected in raw water of a drinking water treatment plant (DWTP), but concentrations of legacy PFASs were high. The U.S. Environmental Protection Agency’s lifetime health advisory level (70 ng/L) for perfluorooctanesulfonic acid and perfluorooctanoic acid (PFOA) was exceeded on 57 of 127 sampling days. In raw water of a DWTP downstream of a PFAS manufacturer, the mean concentration of perfluoro-2-propoxypropanoic acid (PFPrOPrA), a replacement for PFOA, was 631 ng/L (<i>n</i> = 37). Six other PFECAs were detected, with three exhibiting chromatographic peak areas up to 15 times that of PFPrOPrA. At this DWTP, PFECA removal by coagulation, ozonation, biofiltration, and disinfection was negligible. The adsorbability of PFASs on PAC increased with increasing chain length. Replacing one CF₂ group with an ether oxygen decreased the affinity of PFASs for PAC, while replacing additional CF₂ groups did not lead to further affinity changes