TABLE 1.

Mobile phase gradient elution procedure.

Time/Min.	A/%	B/%	Time/Min.	A/%	B/%
0	4	96	65	30	70
5	4	96	70	30	70
10	7.5	92.5	95	50	50
25	15	85	100	50	50
30	15	85	105	95	5
45	20	80	110	95	5
50	20	80