The diluent used was 2.0% formic acid in 10% ACN (aq) prepared
by thorough mixing 50 mL of ACN, 10 mL of formic acid and
440 mL of Milli-Q water. The mobile phase A, 0.1% TFA in water,
was prepared by adding 1 mL of TFA to 900 mL of Milli-Q water
in a 1000 mL volumetric flask and mixing well. The flask was
brought to volume with Milli-Q water and transferred to a mobile
phase container.