99%, MW 287.56 g mol–1), potassium sulfate (K2SO4, 99%, MW 174.24 g mol–1),
sodium chloride (NaCl, 99%, MW 58.44 g mol–1), anhydrous
magnesium sulfate (MgSO4, 99%, MW 120.37 g mol–1), and ethyl alcohol (C2H5OH, 94%) were purchased
from Duksan Pure Chemicals (South Korea). N,N-Dimethylformamide (C3H7NO, 99.5%,
MW 73.1 g mol–1), oxalic acid dihydrate (H2C2O4·2H2O, 99.5–100.2%,
MW 126.07 g mol–1), 5 N sodium hydroxide standard
solution, potassium permanganate (KMnO4, 99.3%, MW 158.03
g mol–1), and manganese(II) sulfate pentahydrate
(MnSO4·5H2O, 98%, MW 241.08 g mol–1) were purchased from Daejung Chemicals & Metals (South Korea).
Calcium sulfate dihydrate (CaSO4·2H2O,
95%, MW 172.17 g mol–1) was purchased from Oriental
Chemical Industries (South Korea). Strontium nitrate (Sr(NO3)2, 99%, MW 211.63 g mol–1) was purchased
from Sigma-Aldrich (USA) and used to prepare simulant solutions. All
solutions were prepared with deionized (D.I.) water (EXL 5 A16, EXL
Service, USA).