Simultaneous analysis of carotenoids and tocopherols in botanical species using one step solid–liquid extraction followed by high performance liquid chromatography

• Published in: Food chemistry 2015-04, Vol.173, p.709-717
• Main Authors: Valdivielso, Izaskun, Bustamante, María Ángeles, Ruiz de Gordoa, Juan Carlos, Nájera, Ana Isabel, de Renobales, Mertxe, Barron, Luis Javier R.
• Format: Article
• Language: English
• Subjects: Botanical species; Carotenoids; Carotenoids - analysis; Chromatography, High Pressure Liquid; Grassland; Hexanes - chemistry; High-performance liquid chromatography (HPLC); Isomerism; Limit of Detection; Mountain grasslands; One-step simultaneous extraction; Plants - chemistry; Reproducibility of Results; Spain; Tocopherols; Tocopherols - analysis; Xanthophylls - analysis
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2014.10.090

•Carotenoids and tocopherols were simultaneously extracted using one-step phase.•Tocopherols, xanthophylls and β-carotene isomers were completely separated by HPLC.•The method allows detection of very low amounts of tocopherols and carotenoids.•Detecting minor compounds in plants is of great interest in looking for biomarkers. Carotenoids and tocopherols from botanical species abundant in Atlantic mountain grasslands were simultaneously extracted using one-step solid–liquid phase. A single n-hexane/2-propanol extract containing both types of compounds was injected twice under two different sets of HPLC conditions to separate the tocopherols by normal-phase chromatography and carotenoids by reverse-phase mode. The method allowed reproducible quantification in plant samples of very low amounts of α-, β-, γ- and δ-tocopherols (LOD from 0.0379 to 0.0720μgg−1 DM) and over 15 different xanthophylls and carotene isomers. The simplified one-step extraction without saponification significantly increased the recovery of tocopherols and carotenoids, thereby enabling the determination of α-tocopherol acetate in plant samples. The two different sets of chromatographic analysis provided near baseline separation of individual compounds without interference from other lipid compounds extracted from plants, and a very sensitive and accurate detection of tocopherols and carotenoids. The detection of minor individual components in botanical species from grasslands is nowadays of high interest in searching for biomarkers for foods derived from grazing animals.