C4 c12perfluorosulfonic acids

Analytical standards of 9 isotope-labeled
PFASs and 18 native PFASs,
including C4–C14 perfluorocarboxylic acids (PFCAs), C4–C12
perfluorosulfonic acids (PFSAs), fluorotelomer sulfonic acids (FTSAs),
and polyfluoroalkyl phosphoric acid diesters (diPAPs) (see full list
in Table S3) were obtained from Wellington
Laboratories (Guelph, ON, Canada). Ultrapure water was prepared using
a Milli-Q Advantage system (Millipore, Billerica, USA). Glacial acetic
acid (100%) was obtained from Merck (Darmstad, Germany), ammonium
acetate from Fluka (Buchs, Switzerland), and ammonium hydroxide and
hydrochloric acid from J.T. Baker (Phillipsburg, NJ, United States).
Methanol was purchased from Fisher Scientific (Leicestershire, UK)
and sodium hydroxide from VWR International (Radnor, PA, USA). Activated
carbon discs (47 mm × 2 mm) were supplied by Futamura Chemical
Co., Ltd. (Nagoya, Aichi, Japan), GF/A filters (47 mm diameter, 1.6
μm pore size) by VWR International (Radnor, PA, USA), and Sartolon
polyamide filters (47 mm diameter, pore size 0.45 μm) from Sartorius
(Göttingen, Germany). Polyurethane foam filters (47 mm diameter,
50 mm height) were obtained from Sunde Skumplast AS (Gan, Norway).
Weak anion exchange solid-phase extraction (WAX-SPE) cartridges (Oasis
WAX, 6 cc, 150 mg sorbent, 30 μm particle size) were purchased
from Waters Corp. (Milford, MA, USA).

Standards of 18 native PFASs,
including C4–C14 perfluorocarboxylic
acids (PFCAs), C4–C12 perfluorosulfonic acids (PFSAs), fluorotelomer
sulfonic acids (FTSAs), and polyfluoroalkyl phosphoric acid diesters
(diPAPs) as well as 9 isotope-labeled PFASs (see full list in Table S2) were obtained from Wellington Laboratories
(Guelph, ON, Canada). Methanol was obtained from Fisher Scientific
(Leicestershire, U.K.), ammonium acetate from Fluka (Buchs, Switzerland),
acetic acid from Merck (Darmstadt, Germany), ammonium hydroxide and
hydrochloric acid from J.T. Baker (Phillipsburg, NJ), and sodium hydroxide
from VWR International (Radnor, PA). Ultrapure water was prepared
using a Milli-Q Advantage system (Millipore, Billerica). Weak anion
exchange solid-phase extraction (WAX-SPE) cartridges (Oasis WAX, 6
cc, 150 mg sorbent, 30 mm particle size) were purchased from Waters
Corp. (Milford, MA). Activated carbon disks (47 mm × 2 mm) were
supplied by Futamura Chemical Co., Ltd. (Nagoya, Aichi, Japan) and
GF/A filters (47 mm diameter, pore size 1.6 μm) from VWR International
(Radnor, PA).