Table 2. Gradient elution profile.

Time(min)	A(%)a	B(%)b
0	70	30
0.5	70	30
4.0	5	95
7.0	5	95
7.1	70	30
10.0	70	30

^amobile phase A: 10 mM Ammonium formate.

^bmobile phase B: methanol.