Presence of Emerging Per- and Polyfluoroalkyl Substances (PFASs) in

Aug 30, 2017 - ACS AuthorChoice - This is an open access article published under a Creative Commons Non-Commercial No Derivative Works (CC-BY-NC-ND) A...
3 downloads 13 Views 1MB Size
Subscriber access provided by UNIVERSITY OF CONNECTICUT

Article

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

Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a free service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are accessible to all readers and citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.

Environmental Science & Technology is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.

Page 1 of 25

Environmental Science & Technology

1

Presence of emerging per- and polyfluoroalkyl substances (PFASs) in river and drinking water

2

near a fluorochemical production plant in the Netherlands

3 4

Wouter A. Gebbink†,*, Laura van Asseldonk†, Stefan P.J. van Leeuwen†

5 6



RIKILT, Wageningen University & Research, 6700 AE Wageningen, the Netherlands.

7 8 9 10

* Corresponding: RIKILT, Wageningen University and Research, P.O. Box 230, NL 6700 AE

11

Wageningen, the Netherlands. E-mail: [email protected]; Tel: +31 (0)317-481453

12 13 14

ACS Paragon Plus Environment

Environmental Science & Technology

15

Abstract

16

The present study investigated the presence of legacy and emerging per- and polyfluoroalkyl

17

substances (PFASs) in river water collected in 2016 up- and downstream from a fluorochemical

18

production plant, as well as in river water from control sites, in the Netherlands. Additionally, drinking

19

water samples were collected from municipalities in the vicinity from the production plant, as well as

20

in other regions in the Netherlands. The PFOA replacement chemical GenX was detected at all

21

downstream river sampling sites with the highest concentration (812 ng/L) at the first sampling

22

location downstream from the production plant, which was 13 times higher than concentrations of sum

23

perfluoroalkylcarboxylic acids and perfluoroalkane sulfonates (∑PFCA+∑PFSA). Using high

24

resolution mass spectrometry, eleven polyfluoroalkyl acids belonging to the C2nH2nF2nO2,

25

C2nH2n+2F2nSO4 or C2n+1H2nF2n+4SO4 homologue series were detected, but only in downstream water

26

samples. These emerging PFASs followed a similar distribution as GenX among the downstream

27

sampling sites, suggesting the production plant as the source. Polyfluoroalkyl sulfonates

28

(C2nH2F4nSO3) were detected in all collected river water samples, and therefore appear to be ubiquitous

29

contaminants in Dutch rivers. GenX was also detected in drinking water collected from 3 out of 4

30

municipalities in the vicinity of the production plant, with highest concentration at 11 ng/L. Drinking

31

water containing the highest level of GenX also contained two C2nH2nF2nO2 homologues.

32 33

Keywords: per- and polyfluoroalkyl substances; replacement chemicals; GenX; river and drinking

34

water

35

ACS Paragon Plus Environment

Page 2 of 25

Page 3 of 25

36

Environmental Science & Technology

TOC Art

37 38 39 40

ACS Paragon Plus Environment

Environmental Science & Technology

41

Introduction

42

Per- and polyfluoroalkyl substances (PFASs) are industrial chemicals that are produced for numerous

43

industrial and consumer products.1 Due to their chemical properties, historically produced PFASs such

44

as perfluoroalkylcarboxylic acids (PFCAs) and perfluoroalkane sulfonates (PFSAs) are classified as

45

persistent, bioaccumulative and/or toxic chemicals. The production of perfluorooctanesulfonate

46

(PFOS) and perfluorooctanoic acid (PFOA) (and their precursors) has been phased out by main

47

producers in North America and Europe. PFCAs and PFSAs are global environmental contaminants

48

and are found in the abiotic and biotic environment.2-4

49 50

Since the phase out of PFASs such as PFOS, PFOA and their precursors, industry has shifted

51

production to shorter chain length PFSAs and PFCAs and other replacement chemicals such as

52

perfluoroalkyl ether acids (e.g., GenX).5,6 Emissions from production plants are a direct source of

53

fluorochemicals into the environment, and with the use of high resolution mass spectrometry (HRMS),

54

several studies have reported on the presence of replacement PFASs in waste water from

55

manufacturing sites or in river water collected downstream from them, with concentrations estimated

56

in the µg/L range.7-10 Emerging PFASs detected in these studies included perfluoroalkyl (mono and

57

poly) ether carboxylic acids including GenX (also named PFPrOPrA or HFPO-DA), polyfluoroalkyl

58

carboxylic acids (C2nH2nF2nO2 homologues), and polyfluorinated alkane sulfonates and sulfates (see

59

Table S7 for proposed chemical structures).

60 61

In the Netherlands, a fluorochemical production plant near the city of Dordrecht historically used

62

PFOA until 2012, but is currently using the PFOA replacement GenX to produce fluoropolymers.11 A

63

previous study reported on the presence of GenX in Dutch river water collected ~50km downstream

64

from the production plant in 2013 at 91 ng/L (12 times higher than PFOA concentrations).12,13

65

However, to our knowledge no other measurements have been reported in Dutch water bodies. In the

66

U.S., GenX concentrations downstream from a production site reached concentrations in the low µg/L

67

range.8 It is unclear what concentrations of GenX are present in the river close to the production plant

ACS Paragon Plus Environment

Page 4 of 25

Page 5 of 25

Environmental Science & Technology

68

in the Netherlands, and/or if also other emerging PFASs are currently being used and emitted to the

69

local environment.

70 71

In the western part of the Netherlands, where the fluorochemical production plant is located, river

72

water is used as the source for drinking water.14 Studies have shown that drinking water treatment

73

plants (DWTP) fail to completely remove legacy PFASs (PFCAs and PFSAs) during the process to

74

produce drinking water.15,16 This was recently also shown for GenX, where raw water and finished

75

water contained comparable concentrations.8 The presence of GenX in river water downstream from

76

the Dordrecht fluorochemical production plant,12 plus the fact that DWTPs poorly remove GenX,

77

raises the question of whether GenX (and other emerging PFASs) could be present in drinking water

78

in the Netherlands and thus be a source for human exposure.

79 80

Therefore the objective of this study was to investigate the presence of GenX and other emerging

81

PFASs in river water near the fluorochemical production plant by performing target analysis and

82

suspect-screening for emerging PFASs reported in the literature. River water was collected from 18

83

locations, both upstream and downstream from the production plant. Target analyses and suspect-

84

screening were also performed on drinking water samples collected from 4 cities in the vicinity of the

85

plant and from 2 cities in central and eastern Netherlands (controls).

86 87

Materials and Methods

88

Chemicals and reagents

89

Target PFASs included C4,6,7,8 PFSAs, C4-10 PFCAs, ADONA, and 6:2 Cl-PFESA were all obtained

90

from Wellington laboratories (Guelph, On, Canada), while GenX was obtained from Apollo Scientific

91

(Cheshire, UK). A total of 11 isotopically-labelled internal standards (Table S1) and recovery

92

standards (13C8-PFOS and

93

solvents and reagents used were of the highest purity commercially available.

13

C8-PFOA) were used, all obtained from Wellington Laboratories. All

94 95

ACS Paragon Plus Environment

Environmental Science & Technology

96

Sample collection and preparation

97

A total of 18 river water samples were taken in October 2016 (Figure 1, Table S2). These included 13

98

samples taken downstream from the production plant (R1-13), 3 samples taken upstream (R14-16),

99

and 2 samples taken from different waterbodies as control sites (R17-18). Drinking water samples

100

were taken at city halls in the municipalities close to the production plant (D1-4), at a residential home

101

in Utrecht (D5), and at RIKILT in Wageningen (D6) (Figure 1, Table S2). All river and drinking water

102

samples were stored in pre-rinsed 1 L high-density polyethylene (HDPE) bottles at 4 °C until chemical

103

analysis. Field blanks were taken by filling HDPE bottles with MilliQ water and stored under the same

104

conditions as the river and drinking water samples. The water sample preparation and LC-MSMS

105

analysis is based on previous studies.4, 14 Briefly, a volume of 250 mL water was spiked with internal

106

standards and loaded onto a WAX SPE cartridge (Waters; 3 mL, 60 mg) preconditioned with 4 mL

107

methanol and 4 mL water. The SPE was subsequently washed with 4 mL sodium acetate buffer (pH 4)

108

and 2 mL methanol. All target compounds were then eluted with 3 mL 2% NH4OH in acetonitrile, and

109

subsequently evaporated under a stream of nitrogen until dryness. The extract was redissolved in 300

110

µL acetonitrile and 675 µL 2 mM ammonium acetate in water and sonicated for 5 min. To a volume of

111

475 µL of this extract, 25 µL recovery standard (13C8-PFOS and 13C8-PFOA at 100 pg/µL) was added

112

and filtered prior to LC-MSMS analysis.

113 114

Target Analysis

115

Target analysis was performed on a Shimazdu Nexera X2 LC-30AD UHPLC (Canby, USA),

116

connected to an AB Sciex Qtrap 5500 triple quadrupole mass spectrometer. Target compounds were

117

separated on an Acquity UPLC BEH C18 column (Waters; 2.1 x 50mm, 1.7µm) and the column was

118

kept at 35 °C. See Table S3 for details on mobile phases and gradient program. Electrospray ionisation

119

in negative mode (ESI-) was used and the ion spray voltage was set at -4500V. The ion source

120

temperature was set at 350 °C. For each target compound two fragments were monitored with

121

optimized MS/MS parameters (see Table S1). Quantification was performed using an isotope dilution

122

approach. Analytes lacking an analogous labelled standard were quantified using the internal standard

123

with the closest retention time (Table S1). Quantification was performed using the precursor-product

ACS Paragon Plus Environment

Page 6 of 25

Page 7 of 25

Environmental Science & Technology

124

ion multiple reaction monitoring (MRM) transitions reported in Table S1. Calibration curves dissolved

125

in water/acetonitrile (70/30), consisting of minimal 9 standards (range 0.05-25 ng/mL), were linear

126

over the whole concentration range with r2 values greater than 0.99. Besides the field blank, method

127

blanks and spiked water samples were included during the analyses. For compounds where blank

128

contamination was observed, the method quantification limits (MQLs) were determined as the mean

129

plus three times the standard deviation of the quantified procedural blank signals. A blank correction

130

was performed by subtracting the average quantified concentration in the blanks from PFAS

131

concentrations in the samples. For other compounds the MQL was determined as the concentration

132

calculated in a sample giving a peak with a signal-to-noise ratio of 10. Table S4 lists all compound-

133

specific MQLs (ranging from 0.01 to 4 ng/L depending on the chemical) and recoveries of native

134

PFASs spiked to water at 3 different concentrations (ranging from 81 to 115% depending on the

135

chemical and spiking concentrations). Internal standard recoveries in the river and drinking water

136

samples are listed in Table S5 and ranged from 46 to 108% depending on the internal standard.

137 138

Suspect-screening analysis

139

Suspect-screening was performed on an Ultimate 3000 UPLC system connected to an QExactive

140

Orbitrap high resolution mass spectrometer (HRMS) (Thermo Scientific, CA, USA). An Atlantis T3

141

column (3 µm particles, 100 × 3 mm; Waters) was used for compound separation. See Table S6 for

142

details on mobile phases and gradient program. The QExactive was operated in negative electrospray

143

ionisation (ESI-) mode in full scan (100-1250 m/z) at a resolution of 140,000. The capillary voltage

144

was set at 2.5 kV, and the capillary and heater temperatures were set at 250 and 400 °C, respectively.

145

MS/MS experiments were performed in order to obtain fragment information for structural

146

confirmation. The combined fragments obtained at collision energies of 20 and 80 eV were detected

147

by the QExactive mass analyser at a resolution of 35,000. Samples were screened for a database of

148

compounds reported in the literature7-10 and potential other homologues differing CF2 (49.9968),

149

CF2CH2 (64.0124), or CF2O (65,9917) in mass.

150 151

ACS Paragon Plus Environment

Environmental Science & Technology

152

Results & Discussion

153

Legacy PFASs in river and drinking water

154

Of the legacy PFASs (C4-10 PFCAs and C4,6,7,8 PFSAs), PFBA, PFPA, PFHxA, PFHpA, PFOA, PFNA,

155

PFDA, PFBS, PFHxS, PFHpS, and PFOS were detected in the river water samples (Table 1).

156

Concentrations of the sum PFCAs and PFSAs were quite consistent among all the samples and ranged

157

from 36 to 65 ng/L (Table 1, Figure 2). Also the sum concentrations from the control sites (R17-18)

158

fell within this range. Highest concentrations of individual PFASs were observed for PFBS, ranging

159

between 12 and 27 ng/L, followed by PFBA, PFPA, PFHxA, PFOA, and PFOS with a comparable

160

concentration range, i.e. 2.7 – 14 ng/L. Concentration of PFOA in the first sampling site downstream

161

from the production plant (R13) was 2.5 to 4.4 times higher compared to the other sampling sites even

162

though production of PFOA ceased in 2012. The pattern of detected PFCAs and PFSAs was

163

comparable for all river water samples and was dominated by shorter chain PFASs (Figure S1). The

164

dominant PFAAs were PFBS, PFBA, and PFHxA and contributed on average 40%, 15% and 11% to

165

∑PFAA, respectively, which was significantly higher (p