Table 2.

Gradient times for USP and BP methods

USP method			BP method
Time (min)	% A	% B	Time (min)	% A	% B
0	100	0	0	100	0
12	100	0	13	100	0
20	0	100	21	0	100
22	0	100	25	0	100
23	100	0	26	100	0
30	100	0	35	100	0