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Presence of emerging per- and polyfluoroalkyl substances (PFASs) in river and drinking water near a fluorochemical production plant in the Netherlands Wouter A Gebbink, Laura van Asseldonk, and Stefan van Leeuwen Environ. Sci. Technol., Just Accepted Manuscript • DOI: 10.1021/acs.est.7b02488 • Publication Date (Web): 30 Aug 2017 Downloaded from http://pubs.acs.org on September 1, 2017
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Presence of emerging per- and polyfluoroalkyl substances (PFASs) in river and drinking water
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near a fluorochemical production plant in the Netherlands
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Wouter A. Gebbink†,*, Laura van Asseldonk†, Stefan P.J. van Leeuwen†
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†
RIKILT, Wageningen University & Research, 6700 AE Wageningen, the Netherlands.
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* Corresponding: RIKILT, Wageningen University and Research, P.O. Box 230, NL 6700 AE
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Wageningen, the Netherlands. E-mail:
[email protected]; Tel: +31 (0)317-481453
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Abstract
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The present study investigated the presence of legacy and emerging per- and polyfluoroalkyl
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substances (PFASs) in river water collected in 2016 up- and downstream from a fluorochemical
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production plant, as well as in river water from control sites, in the Netherlands. Additionally, drinking
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water samples were collected from municipalities in the vicinity from the production plant, as well as
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in other regions in the Netherlands. The PFOA replacement chemical GenX was detected at all
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downstream river sampling sites with the highest concentration (812 ng/L) at the first sampling
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location downstream from the production plant, which was 13 times higher than concentrations of sum
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perfluoroalkylcarboxylic acids and perfluoroalkane sulfonates (∑PFCA+∑PFSA). Using high
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resolution mass spectrometry, eleven polyfluoroalkyl acids belonging to the C2nH2nF2nO2,
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C2nH2n+2F2nSO4 or C2n+1H2nF2n+4SO4 homologue series were detected, but only in downstream water
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samples. These emerging PFASs followed a similar distribution as GenX among the downstream
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sampling sites, suggesting the production plant as the source. Polyfluoroalkyl sulfonates
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(C2nH2F4nSO3) were detected in all collected river water samples, and therefore appear to be ubiquitous
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contaminants in Dutch rivers. GenX was also detected in drinking water collected from 3 out of 4
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municipalities in the vicinity of the production plant, with highest concentration at 11 ng/L. Drinking
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water containing the highest level of GenX also contained two C2nH2nF2nO2 homologues.
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Keywords: per- and polyfluoroalkyl substances; replacement chemicals; GenX; river and drinking
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water
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Introduction
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Per- and polyfluoroalkyl substances (PFASs) are industrial chemicals that are produced for numerous
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industrial and consumer products.1 Due to their chemical properties, historically produced PFASs such
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as perfluoroalkylcarboxylic acids (PFCAs) and perfluoroalkane sulfonates (PFSAs) are classified as
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persistent, bioaccumulative and/or toxic chemicals. The production of perfluorooctanesulfonate
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(PFOS) and perfluorooctanoic acid (PFOA) (and their precursors) has been phased out by main
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producers in North America and Europe. PFCAs and PFSAs are global environmental contaminants
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and are found in the abiotic and biotic environment.2-4
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Since the phase out of PFASs such as PFOS, PFOA and their precursors, industry has shifted
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production to shorter chain length PFSAs and PFCAs and other replacement chemicals such as
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perfluoroalkyl ether acids (e.g., GenX).5,6 Emissions from production plants are a direct source of
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fluorochemicals into the environment, and with the use of high resolution mass spectrometry (HRMS),
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several studies have reported on the presence of replacement PFASs in waste water from
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manufacturing sites or in river water collected downstream from them, with concentrations estimated
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in the µg/L range.7-10 Emerging PFASs detected in these studies included perfluoroalkyl (mono and
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poly) ether carboxylic acids including GenX (also named PFPrOPrA or HFPO-DA), polyfluoroalkyl
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carboxylic acids (C2nH2nF2nO2 homologues), and polyfluorinated alkane sulfonates and sulfates (see
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Table S7 for proposed chemical structures).
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In the Netherlands, a fluorochemical production plant near the city of Dordrecht historically used
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PFOA until 2012, but is currently using the PFOA replacement GenX to produce fluoropolymers.11 A
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previous study reported on the presence of GenX in Dutch river water collected ~50km downstream
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from the production plant in 2013 at 91 ng/L (12 times higher than PFOA concentrations).12,13
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However, to our knowledge no other measurements have been reported in Dutch water bodies. In the
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U.S., GenX concentrations downstream from a production site reached concentrations in the low µg/L
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range.8 It is unclear what concentrations of GenX are present in the river close to the production plant
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in the Netherlands, and/or if also other emerging PFASs are currently being used and emitted to the
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local environment.
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In the western part of the Netherlands, where the fluorochemical production plant is located, river
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water is used as the source for drinking water.14 Studies have shown that drinking water treatment
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plants (DWTP) fail to completely remove legacy PFASs (PFCAs and PFSAs) during the process to
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produce drinking water.15,16 This was recently also shown for GenX, where raw water and finished
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water contained comparable concentrations.8 The presence of GenX in river water downstream from
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the Dordrecht fluorochemical production plant,12 plus the fact that DWTPs poorly remove GenX,
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raises the question of whether GenX (and other emerging PFASs) could be present in drinking water
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in the Netherlands and thus be a source for human exposure.
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Therefore the objective of this study was to investigate the presence of GenX and other emerging
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PFASs in river water near the fluorochemical production plant by performing target analysis and
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suspect-screening for emerging PFASs reported in the literature. River water was collected from 18
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locations, both upstream and downstream from the production plant. Target analyses and suspect-
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screening were also performed on drinking water samples collected from 4 cities in the vicinity of the
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plant and from 2 cities in central and eastern Netherlands (controls).
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Materials and Methods
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Chemicals and reagents
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Target PFASs included C4,6,7,8 PFSAs, C4-10 PFCAs, ADONA, and 6:2 Cl-PFESA were all obtained
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from Wellington laboratories (Guelph, On, Canada), while GenX was obtained from Apollo Scientific
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(Cheshire, UK). A total of 11 isotopically-labelled internal standards (Table S1) and recovery
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standards (13C8-PFOS and
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solvents and reagents used were of the highest purity commercially available.
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C8-PFOA) were used, all obtained from Wellington Laboratories. All
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Sample collection and preparation
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A total of 18 river water samples were taken in October 2016 (Figure 1, Table S2). These included 13
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samples taken downstream from the production plant (R1-13), 3 samples taken upstream (R14-16),
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and 2 samples taken from different waterbodies as control sites (R17-18). Drinking water samples
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were taken at city halls in the municipalities close to the production plant (D1-4), at a residential home
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in Utrecht (D5), and at RIKILT in Wageningen (D6) (Figure 1, Table S2). All river and drinking water
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samples were stored in pre-rinsed 1 L high-density polyethylene (HDPE) bottles at 4 °C until chemical
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analysis. Field blanks were taken by filling HDPE bottles with MilliQ water and stored under the same
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conditions as the river and drinking water samples. The water sample preparation and LC-MSMS
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analysis is based on previous studies.4, 14 Briefly, a volume of 250 mL water was spiked with internal
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standards and loaded onto a WAX SPE cartridge (Waters; 3 mL, 60 mg) preconditioned with 4 mL
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methanol and 4 mL water. The SPE was subsequently washed with 4 mL sodium acetate buffer (pH 4)
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and 2 mL methanol. All target compounds were then eluted with 3 mL 2% NH4OH in acetonitrile, and
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subsequently evaporated under a stream of nitrogen until dryness. The extract was redissolved in 300
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µL acetonitrile and 675 µL 2 mM ammonium acetate in water and sonicated for 5 min. To a volume of
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475 µL of this extract, 25 µL recovery standard (13C8-PFOS and 13C8-PFOA at 100 pg/µL) was added
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and filtered prior to LC-MSMS analysis.
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Target Analysis
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Target analysis was performed on a Shimazdu Nexera X2 LC-30AD UHPLC (Canby, USA),
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connected to an AB Sciex Qtrap 5500 triple quadrupole mass spectrometer. Target compounds were
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separated on an Acquity UPLC BEH C18 column (Waters; 2.1 x 50mm, 1.7µm) and the column was
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kept at 35 °C. See Table S3 for details on mobile phases and gradient program. Electrospray ionisation
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in negative mode (ESI-) was used and the ion spray voltage was set at -4500V. The ion source
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temperature was set at 350 °C. For each target compound two fragments were monitored with
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optimized MS/MS parameters (see Table S1). Quantification was performed using an isotope dilution
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approach. Analytes lacking an analogous labelled standard were quantified using the internal standard
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with the closest retention time (Table S1). Quantification was performed using the precursor-product
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ion multiple reaction monitoring (MRM) transitions reported in Table S1. Calibration curves dissolved
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in water/acetonitrile (70/30), consisting of minimal 9 standards (range 0.05-25 ng/mL), were linear
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over the whole concentration range with r2 values greater than 0.99. Besides the field blank, method
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blanks and spiked water samples were included during the analyses. For compounds where blank
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contamination was observed, the method quantification limits (MQLs) were determined as the mean
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plus three times the standard deviation of the quantified procedural blank signals. A blank correction
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was performed by subtracting the average quantified concentration in the blanks from PFAS
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concentrations in the samples. For other compounds the MQL was determined as the concentration
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calculated in a sample giving a peak with a signal-to-noise ratio of 10. Table S4 lists all compound-
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specific MQLs (ranging from 0.01 to 4 ng/L depending on the chemical) and recoveries of native
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PFASs spiked to water at 3 different concentrations (ranging from 81 to 115% depending on the
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chemical and spiking concentrations). Internal standard recoveries in the river and drinking water
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samples are listed in Table S5 and ranged from 46 to 108% depending on the internal standard.
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Suspect-screening analysis
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Suspect-screening was performed on an Ultimate 3000 UPLC system connected to an QExactive
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Orbitrap high resolution mass spectrometer (HRMS) (Thermo Scientific, CA, USA). An Atlantis T3
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column (3 µm particles, 100 × 3 mm; Waters) was used for compound separation. See Table S6 for
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details on mobile phases and gradient program. The QExactive was operated in negative electrospray
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ionisation (ESI-) mode in full scan (100-1250 m/z) at a resolution of 140,000. The capillary voltage
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was set at 2.5 kV, and the capillary and heater temperatures were set at 250 and 400 °C, respectively.
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MS/MS experiments were performed in order to obtain fragment information for structural
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confirmation. The combined fragments obtained at collision energies of 20 and 80 eV were detected
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by the QExactive mass analyser at a resolution of 35,000. Samples were screened for a database of
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compounds reported in the literature7-10 and potential other homologues differing CF2 (49.9968),
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CF2CH2 (64.0124), or CF2O (65,9917) in mass.
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Results & Discussion
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Legacy PFASs in river and drinking water
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Of the legacy PFASs (C4-10 PFCAs and C4,6,7,8 PFSAs), PFBA, PFPA, PFHxA, PFHpA, PFOA, PFNA,
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PFDA, PFBS, PFHxS, PFHpS, and PFOS were detected in the river water samples (Table 1).
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Concentrations of the sum PFCAs and PFSAs were quite consistent among all the samples and ranged
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from 36 to 65 ng/L (Table 1, Figure 2). Also the sum concentrations from the control sites (R17-18)
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fell within this range. Highest concentrations of individual PFASs were observed for PFBS, ranging
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between 12 and 27 ng/L, followed by PFBA, PFPA, PFHxA, PFOA, and PFOS with a comparable
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concentration range, i.e. 2.7 – 14 ng/L. Concentration of PFOA in the first sampling site downstream
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from the production plant (R13) was 2.5 to 4.4 times higher compared to the other sampling sites even
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though production of PFOA ceased in 2012. The pattern of detected PFCAs and PFSAs was
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comparable for all river water samples and was dominated by shorter chain PFASs (Figure S1). The
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dominant PFAAs were PFBS, PFBA, and PFHxA and contributed on average 40%, 15% and 11% to
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∑PFAA, respectively, which was significantly higher (p
