Table 2. HPLC gradient conditions for retinol and β-carotene simultaneous analyses

Time (min) A1) (%) B2) (%)
0 75 25
8 75 25
50 10 90
55 10 90
57 75 25
65 75 25
Mobile phase A: methanol:butanol:water=89.5:10:0.5 (v/v/v).
Mobile phase B: methanol:butanol:water=60:10:30 (v/v/v).