Article pubs.acs.org/est
Closing the Mass Balance on Fluorine on Papers and Textiles Alix E. Robel,† Kristin Marshall,† Margaret Dickinson,‡ David Lunderberg,‡ Craig Butt,§ Graham Peaslee,∥ Heather M. Stapleton,§ and Jennifer A. Field*,† †
Department of Environmental and Molecular Toxicology, 2750 Campus Way, Oregon State University, Corvallis, Oregon 97331, United States ‡ Science Center Rm 2106A, 35 East 12th Street, Holland, Michigan 49422-9000, United States § Nicholas School of the Environment, Duke University, Durham, North Carolina 27708, United States ∥ Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556, United States S Supporting Information *
ABSTRACT: Papers and textiles that are treated with per- and polyfluoroalkyl substances (PFASs) are sources of human and environmental exposure. Data for individual PFASs, such as perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA), are not placed into the context of total fluorine for papers and textiles. Gas chromatography−mass spectrometry (GC−MS) and liquid chromatography−tandem mass spectrometry (LC-MS/MS) were used to quantify volatile and ionic PFASs, respectively, and the total oxidizable precursor (TOP) assay was used to quantify precursors that form perfluoroalkyl carboxylates. Molar sums of PFASs obtained by GC-MS, LC-MS/MS, and precursors were compared to total fluorine (nmol F/cm2) determined by particle-induced gamma ray emission (PIGE) spectroscopy, measured before and after extraction. Volatile and ionic PFASs and unknown precursors accounted for 0−2.2%, 0−0.41%, and 0.021−14%, respectively, of the total nmol F/ cm2 determined by PIGE. After extraction, papers and textiles retained 64 ± 28% to 110 ± 30% of the original nmol F/cm2 as determined by PIGE, indicating that the majority of fluorine remains associated with the papers and textiles. The sum of PFASs in the volatile, ionic, and precursor fraction, and total fluorine after extraction indicate that mass balance was achieved (within analytical error) of the initial total fluorine measured by PIGE.
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INTRODUCTION Due to their unique chemical properties, per- and polyfluoroalkyl substances (PFASs) are used in fire-fighting foams, coatings, and consumer products.1,2 PFASs are rapidly gaining attention due to the detection of select PFASs in humans,3−5environmental media,6−12 and in remote locations.13−15 Until recently, the primary focus is on perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA), the only two forms of PFASs that have US EPA health advisory values.16 However, attention is shifting to the identification of additional PFASs in commerce17,18 that may degrade to persistent perfluoroalkyl carboxylates (PFCAs) and other forms.17,19 Few of the newly identified PFASs (e.g., ether sulfonates,20 short-chain perfluoroalkyl sulfonamides,21cyclic sulfonates22) have any toxicological data, and there is growing evidence of a larger number of PFASs in human blood.4,23,24 Human exposure pathways to PFASs includes inhalation of volatiles25−27 and ingestion of dust.26−29 Although dermal exposure for other contaminants, such as phthalates, is considered low,30,31 only two studies32,33 that focus exclusively on PFOA currently exist and thus dermal transfer warrants future research. Studies that focus on consumer products that are treated with or contain PFASs, such as carpets, papers, textiles, and plastics, typically focus either on the volatile (e.g., fluorotelomer alcohols, © XXXX American Chemical Society
FTOHs) or on ionic PFASs (e.g., C4−C14 PFCAs) and even carbon-numbered (C4, C6, and C8) perfluoroalkyl sulfonates (PFSAs).34−48 Relatively few studies address both volatile and ionic PFASs,49−55 and only some capture a larger array of individual PFASs including perfluoroalkyl sulfonamides, perfluoroalkyl sulfonamidoethanols, phosphorus-containing PFASs, and saturated and unsaturated fluorotelomer carboxylates (FTCAs and FTUCAs).46,47 Current techniques to quantify total fluorine include combustion ion chromatography4,23,24,56 and total adsorbable fluorine57,58 on human blood and water, respectively. Alternatively, the total oxidizable precursor (TOP) assay was developed to quantify precursors that oxidize to PFCAs in urban runoff,59 groundwater and soil,9,60 and wastewater.11 Gruber et al.61 applied the TOP assay to geotextiles that are used on roofs and to create landscape barriers. However, to date, the mass of precursors determined by the TOP assay has not been compared to an independent measure of total fluorine in any matrix, including papers and textiles. A new technique, particleReceived: Revised: Accepted: Published: A
April 21, 2017 July 14, 2017 July 14, 2017 July 15, 2017 DOI: 10.1021/acs.est.7b02080 Environ. Sci. Technol. XXXX, XXX, XXX−XXX
Article
Environmental Science & Technology
Table 1. Total nmol F/cm2 for Volatile PFASs, Ionic Individual PFASs, and Precursors from the TOP Assay for Papers and Textiles Purchased New in 2015, except for Textile 9, Which Is a Used Office Chair with a Manufacture Date of 1988a Papers
Textiles
1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 9
Material Type
Σ Volatile PFASs (nmol F/cm2)
Σ Ionic PFASs (nmol F/cm2)
Σ Precursors (nmol F/cm2)
FC Copy Paperb FC Gift Bag FC FC FCb Popcorn bag Children’s Fabric Children’s Fabric Jacket Jacket Jacket Hat Pillowcase Jacket Office Upholstery
0.16 ± 0.004 0.013 ± 0.001
