title: UPLC method for the determination of vitamin E homologues and derivatives in vegetable oils, margarines and supplement capsules using pentafluorophenyl column.
abstract: A sensitive and rapid reversed-phase ultra performance liquid chromatographic (UPLC) method for the simultaneous determination of tocopherols (α-, β-, γ-, δ-), tocotrienols (α-, β-, γ-, δ-), α-tocopherol acetate and α-tocopherol nicotinate is described. The separation was achieved using a Kinetex pentafluorophenyl (PFP) column (150 × 2.1mm, 2.6 µm) with both photodiode array (PDA) and fluorescence (FL) detectors that were connected in series. Column was thermostated at 42°C. Under a gradient system consisting of methanol and water at a constant flow rate of 0.38 mL min(-1), all the ten analytes were well separated in less than 9.5 min. The method was validated in terms of linearity, limits of detection and quantitation, precision and recoveries. Calibration curves of the ten compounds were well correlated (r(2)>0.999) within the range of 100 to 25,000 μg L(-1) for α-tocopherol acetate and α-tocopherol nicotinate, 10 to 25,000 μg L(-1) for α-tocotrienol and 5 to 25,000 μg L(-1) for the other components. The method is simple and sensitive with detection limits (S/N, 3) of 1.0 to 3.0 μg L(-1) (FL detection) and 30 to 74 μg L(-1) (PDA detection). Relative standard deviations for intra- and inter-day retention times (<1%) and peak areas (≤ 4%) were obtained. The method was successfully applied to the determination of vitamin E in vegetable oils (extra virgin olive, virgin olive, pomace olive, blended virgin and refined olive, sunflower, soybean, palm olein, carotino, crude palm, walnut, rice bran and grape seed), margarines and supplements.
authors.affiliation: School of Chemical Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia.
authors.forename: Yong Foo
authors.initials: YF
authors.lastname: Wong
authors.affiliation: School of Chemical Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia.
authors.forename: Ahmad
authors.initials: A
authors.lastname: Makahleh
authors.affiliation: School of Chemical Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia. Electronic address: bahrud@usm.my.
authors.forename: Bahruddin
authors.initials: B
authors.lastname: Saad
authors.affiliation: School of Chemical Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia.
authors.forename: Mohamad Nasir Mohamad
authors.initials: MN
authors.lastname: Ibrahim
authors.affiliation: School of Chemical Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia.
authors.forename: Afidah Abdul
authors.initials: AA
authors.lastname: Rahim
authors.affiliation: Laboratoire d'Etude et de Recherche sur le MAteriau Bois, Faculté des Sciences et Techniques, Nancy-Université, Bld des Aiguillettes, F-54500 Vandoeuvre-lès-Nancy, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Brosse
mesh_terms: D000975:Antioxidants / Q000032:analysis*; D002214:Capsules; D002853:Chromatography, Liquid; D056148:Chromatography, Reverse-Phase; D019587:Dietary Supplements / Q000032:analysis*; D017879:Isothiocyanates / Q000737:chemistry*; D057230:Limit of Detection; D008383:Margarine / Q000032:analysis*; D010938:Plant Oils / Q000737:chemistry*; D024505:Tocopherols / Q000032:analysis* / Q000302:isolation & purification; D024508:Tocotrienols / Q000032:analysis* / Q000302:isolation & purification; D005464:Fluorobenzenes; D005466:Fluorocarbons
chemical_list: D000975:Antioxidants; D002214:Capsules; D017879:Isothiocyanates; D008383:Margarine; D010938:Plant Oils; D024505:Tocopherols; D024508:Tocotrienols; C003064:pentafluorophenylisothiocyanate; D005464:Fluorobenzenes; D005466:Fluorocarbons
keywords: Margarines; Pentafluorophenyl column; Supplements; UPLC; Vegetable oils; Vitamin E