Table 1.

Gradient and flow rates for chromatographic separation of the oxysterols and bile acids

Time (min)	Flow rate (ml/min)	%A	%B	%C
0.0	0.200	70.0	20.0	10.0
5.0	0.200	48.3	31.7	20.0
10.0	0.300	26.6	53.4	20.0
15.0	0.400	5.0	55.0	40.0
20.0	0.400	5.0	35.0	60.0
25.0	0.400	5.0	5.0	90.0
25.1	0.200	70.0	20.0	10.0
30.0	0.200	70.0	20.0	10.0

Phase A is composed of a mixture of water and acetonitrile (95:5, v/v), whereas phases B and C are composed of acetonitrile and methanol, respectively. Each phase contains 0.1% formic acid.