Tetrahydrofuran

Analytical grade chemicals including 1-hexanol (≥ 99%, d = 0.814 g mL⁻¹), 1-dodecanol (≥ 98.0%, d = 0.83 g cm⁻³), 1-decanol (≥ 99.0%, d = 0.80 g cm⁻³), 1-tetradecanol (≥ 97%, d = 0.823 g cm⁻¹, Sigma), and tetrahydrofuran (Carlo Erba, THF) were used to prepare alkanol-based SUPRASs. Ultrapure water was prepared by Milli-Q water purification system (Millipore, Bedford, MA, USA). Stock solution (1000 mg L⁻¹) of Al(III) ion was prepared from Al(NO₃)₃ salt (Sigma, St Louis, MO, USA) in water and stored at 4 °C in a refrigerator. A stock solution of morinhydrate was prepared in ethanol at a concentration of 1000 mg L⁻¹ (Carlo Erba, Milan, Italy) and stored in dark. The calibration solutions were freshly prepared by sequential dilution of the stock solutions. A 5% (w/v) of KCl solution was prepared by dissolving 5.0 g of KCl (Sigma) in 100 mL deionized water. Borate, acetate, phthalate, and citrate buffer solutions were used to adjust solutions pH. To minimize all possible contamination of glassware, a diluted HNO₃ solution was used for washing glassware and finally rinsed with distilled water.