3 x 4 mL of 2NapFF-Na solution at a concentration of 40 mg/mL were prepared using the quantities in Section 1.3. Solutions were made in Sterilin vials, wrapped in Parafilm, and left to stir for 2 days at 400 rpm using 13x3 mm stirrer bars. The pH was adjusted to pH 10.5 ± 0.1 using 0.1M, 1 M and 2M NaOH; or 1 M and 2 M HCl as required.