Table 1. RRLC gradient^a elution program for the separation of fat- and water-soluble vitamins on Agilent Poroshell 120 EC-C18 reverse phase column.

Time (min)	Flow rate(ml/min)	Solvent Ab(%, v/v)	Solvent Bc(%, v/v)
Fat-soluble vitamins
0	0.3	10	90
3	0.3	10	90
4	0.3	0	100
17	0.3	0	100
18	0.3	10	90
25	0.3	10	90
Water-soluble vitamins
0	0.3	90	10
8	0.3	45	55
10	0.3	45	55
11	0.3	90	10
18	0.3	90	10

^a Total run time = 25 and 20 min, for fat- and water- soluble vitamins, respectively; post time = 5 min for fat- and water-soluble vitamins.

^b A = 0.1% formic acid in water +10 mM ammonium formate.

^c B = 0.1% formic acid in methanol +10 mM ammonium formate.