HPLC analysis of carotenoids and a-tocopherol
Carotenoids and tocopherol were analysed according to
Darnoko et al. (2000). The HPLC system consisted of a
Shimadzu chromatograph (LC 10-AS HPLC), equipped
with dual pump and UV detector (SPD 10A). The column
was a YMC C30 Carotenoid column 250 9 4.6 mm, 5 mm
(YMC, Wilmington, NC). The mobile phase for thiscolumn was 81:15:4 methanol: methyl tertiary butyl ether
(MTBE): Water (solvent A) and 91:9 MTBE: methanol
(solvent B). The gradient elution was 0–50% B in 45 min
followed by 0% B in the next 5 min at a flow rate of 1 mL/
min. Carotenoids (lutein and b-carotene) were monitored at
450 nm and a-tocopherol at 295 nm.