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  • Determination of lutein by high-performance thin-layer chromatography using densitometry and screening of major dietary carotenoids in food supplements
    Rodić, Zoran, farmacija ...
    The main problem in the densitometric determination of carotenoids is their rapid degradation during and immediately after chromatography, respectively. In this study, we show that 15 ng of lutein, ... lycopene and ?-carotene standardsapplied on C18 RP high-performance thin-layer chromatography (HPTLC) plates pre-developed with dichloromethane-methanol 1:1 (v/v) remained stable for 1 h after the development of chromatogram using methanol-acetone 1:1 (v/v)with 0.1% of 2-tert-butylhydroquinone (TBHQ), which is a substantial improvement of their stability. An HPTLC quantification procedure for free lutein, with densitometry at 450 nm based on the developed method described above, was established and validated. Repeatabilities of the chromatography expressed by the relative standard deviation (RSD) from 6 applications of lutein standard at 5, 15 and 25 ng were 3.41, 1.33 and 1.65%, respectively. The best fit calibration curve from 5 ng to 30 ng of lutein was polynomial. Limit of detection (1.5 ng) and limit of quantification (5 ng) were the best achieved so far. With these chromatographic conditions dietary carotenoids lutein esters, lycopene, free lutein and ?-carotene from food supplements werealso well separated and were identified by visible absorption spectra scanned in situ and by mass spectra. Some additional developing solvents with the same type of chromatographic layer are proposed for the fast separation oflutein esters from free lutein in food supplements
    Vir: Journal of chromatography. A. - ISSN 0021-9673 (Vol. 1231, 2012, Str. 59-65)
    Vrsta gradiva - članek, sestavni del
    Leto - 2012
    Jezik - angleški
    COBISS.SI-ID - 4915226