A hydrofluoric acidfree method to dissolve and quantify silica ...
Water (5 mL), HCl (1 M, 5 mL) and NH 4 F (1 M, 1 mL) were added, and the mixtures were stirred at 25 °C in a water bath for 45 min. Mixing a 5fold excess of HCl with NH 4 F produces HF in situ ...