Perfluorobutanoic acid (PFBA; CAS# 375–22-4, 98%) and perfluorobutane sulfonic acid (PFBS; CAS# 375–73-5, 98% purity) were purchased from TCI America. Perfluorooctanoic acid (PFOA; CAS# 335–67-1, 98%) was purchased from AIKE Reagent. Sodium perfluorooctanoate (Na-PFOA; CAS# 335–95-5, 97%) was purchased from Manchester Organics. Potassium perfluorooctane sulfonate (K-PFOS; CAS# 1763–23-1, 98%) was purchased from Matrix Scientific. Perfluorohexanoic acid (PFHxA; CAS# 307–24-4, 97%), perfluoroheptanoic acid (PFHpA; CAS#375–85-9, 99%), potassium perfluorohexane sulfonate (K-PFHxS; CAS# 3871–99-6, >98%), and perfluorooctane sulfonic acid (PFOS; CAS# 1763–23-1, 98%), were purchased from Sigma Aldrich.Perfluorononanoic acid (PFNA; CAS#375–95-1, 97%) was purchased from Shanghai Macklin Biochemical Co., Ltd. Perfluorodecanoic acid (PFDA; CAS#335–76-2, 98%) was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.
All background solutions were prepared with distilled, deionized water. Measurements were conducted with background solutions of 0.01 M NaCl or SGW. The SGW pH is 7.7 and ionic strength is 0.01 M, and it is comprised of the cations (concentration in mg/L) Na+1 (50), Ca+2 (36), and Mg+2 (25), and anions NO3−1 (6), Cl−1 (60), CO3−2/HCO3−1 (133), and SO4−2 (99).
All background solutions were prepared with distilled, deionized water. Measurements were conducted with background solutions of 0.01 M NaCl or SGW. The SGW pH is 7.7 and ionic strength is 0.01 M, and it is comprised of the cations (concentration in mg/L) Na+1 (50), Ca+2 (36), and Mg+2 (25), and anions NO3−1 (6), Cl−1 (60), CO3−2/HCO3−1 (133), and SO4−2 (99).