Sodium sulfate

Sodium hypochlorite (NaClO, 14%), sodium hydrogen phosphate (NaH₂PO₄), sodium chloride (NaCl), calcium chloride dihydrate (CaCl₂∙2H₂O), magnesium sulfate heptahydrate (MgSO₄∙7H₂O), sodium hydrogen carbonate (NaHCO₃), potassium nitrate (KNO₃), sodium nitrate (NaNO₃), calcium carbonate (CaCO₃), magnesium chloride hexahydrate (MgCl₂∙6H₂O), potassium sulfate (K₂SO₄), sodium sulfate (Na₂SO₄), calcium sulfate dihydrate (CaSO₄∙2H₂O), boric acid (H₃BO₃, 0.5%), hydrogen peroxide (H₂O₂, 30%), and chloride acid (HCl, 0.1 M) were purchased from Scharlab S.L., Barcelona, Spain. The ultrapure water (Milli-Q) used in the experiments was obtained from Millipore, Molsheim, France, equipment (conductivity less than 0.055 µS cm⁻¹).
Polyvinyl chloride (PVC, Mw 112,000 g mol⁻¹) was supplied by ATOCHEM, Madrid, Spain. Tetrahydrofuran (THF) was purchased from Scharlab S.L. Amberlite^® IRA-402 (Cl⁻ form, total exchange capacity ≥ 1.0 mol L⁻¹) was supplied by Merck Life Science, Darmstadt, Germany, S.L.U.

Sodium hypochlorite (NaClO, 14%), tetrahydrofuran (THF), sodium chloride (NaCl), sodium sulfate (Na₂SO₄) and sodium nitrate (NaNO₃) were purchased from Scharlab S.L., Barcelona, Spain Polyvinylchloride (PVC, Mw = 112,000 g·mol⁻¹) was supplied by ATOCHEM S.A., Madrid, Spain. Amberlite^® IRA-402 and Lewatit^® Sybron Ionac^® SR-7 anion exchange resins were supplied by Merck KGaA, Darmstadt, Germany. Purolite^® A600/9413 anion exchange resin was supplied by MemBrain^® s.r.o., Stráž pod Ralskem, Czech Republic. The characteristics of the anion exchange resins are reported in Table 1. MilliQ water was used throughout the experiments.

Propyl Paraben (>99% purity), humic acid, sodium chloride, and sodium bicarbonate were supplied from Aldrich. Sodium sulfate was purchased from Scharlau. Acetonitrile HPLC grade was supplied from PanReac AppliChem (Barcelona, Spain). The physico-chemical characterization of the synthetic or environmental matrices investigated is summarized in Table 1.