Table 1.

HPLC mobile phase gradient *.

Time (min)	A (%)	B (%)	C (%)
0	96	2	2
40	50	25	25
45	40	30	30
50	0	50	50
52	0	50	50
55	96	2	2

* (A) water with 0.2% H3PO4 (v/v), (B) methanol and (C) acetonitrile.