Samples were injected on a Phenomenex Kinetex 1.7 µm EVO C18 100 Å, 100 x 1.0 mm column and run using the following gradient with water + 0.1% formic acid (A) and acetonitrile + 0.1% formic acid (B): 5 min, 10% B, 19 min, 100% B, 22 min 100% B, 22.5 min 10% B, 25 min 10% B.