2.7.2. Chromatographic condition.
The Waters HILIC column (100*2.1 mm, 1.7 µm) was used. For the positive ion mode, mobile phase A was aqueous containing 10 mL ammonium acetate. Mobile phase B was an acetonitrile solution containing 0.1% formic acid in the organic phase. The flow rate was set at 0.4 mL/min and the column temperature was set at 40°C.