Simultaneous Determination of Chlorophylls, Pheophytins, β‐Carotene, Tocopherols, and Tocotrienols in Olive and Soybean Oils by High‐performance Liquid Chromatography

A high‐performance liquid chromatographic method is described for the simultaneous measurement of chlorophylls, pheophytins, β‐carotene, tocopherols, and tocotrienols in vegetable oils using 2 spectrophotometers in series and 1 normal‐phase silica column. Oil samples were diluted in the mobile phase, isopropanol‐hexane (1.5:98.5 vol/vol), and injected directly onto the column. A programmable UV/Vis spectrophotometer was used to measure chlorophylls a and b , pheophytins a and b , and β‐carotene at their appropriate absorption maxima (430, 452, 409, 433, and 452 nm, respectively). α‐, γ‐, and δ‐tocopherols and α‐, γ‐, and δ‐tocotrienols were measured by fluorescence at 295‐nm excitation and 330‐nm emission. Samples of virgin olive oil, soybean oil, and palm oil were analyzed.