Table 1.

Chromatographic gradient

Time (min)	% Phase A	% Phase B	Flow (mL/min)
0.00	95	5	0.4
0.30	95	5	0.4
0.35	70	30	0.4
1.50	30	70	0.4
1.80	10	90	0.4
2.80	10	90	0.4
2.90	95	5	0.4
4.00	95	5	0.4

Phase A: H₂O + 0.05% formic acid; Phase B: ACN + 0.05% formic acid.