Development and Evaluation of a Normal Phase Liquid Chromatographic Method for the Determination of Tocopherols and Tocotrienols in Walnuts

Abstract

A high performance liquid chromatographic (HPLC) method for the determination of tocopherols and tocotrienols in walnut samples is described. The compounds were extracted with n-hexane, using a simple solid-liquid extraction procedure. Tocol was used as internal standard and BHT as anti-oxidant. The ehromatographic separation was achieved using an Inertsil 5 SI normal phase column operating with isocratic elution of n-hexane/1,4-dioxane (96.5:3.5, v/v), at a flow rate of 0.7 mL/min. The effluent was monitored by a series arrangement of a diodearray detector followed by a fluorescence detector. The detection limits were low, between 0.037 and 0.266 (jig/mL. The method was precise (% CV less than

Chemical Characterization of “Alcaparras” Stoned Table Olives from Northeast Portugal

“…Tocopherols were evaluated following the ISO 9936 international standard [ 28 ], with some modifications as implemented by Amaral et al . [ 29 ]. A sample of extracted oil (50 mg) was blended with an appropriate amount of internal standard (tocol, Matreya, Inc.) in a volume of n -hexane (1.5 mL), homogenized by stirring, centrifuged at 13,000 g and analyzed by HPLC.…”

Influence of strawberry tree (Arbutus unedo L.) fruit ripening stage on chemical composition and antioxidant activity

“…Tocopherols were evaluated following an international standard (ISO 9936:, 2006) with some modifications (Amaral et al, 2005). Tocopherols and tocotrienols standards (α, β, γ and δ) were purchase from Calbiochem (La Jolla, San Diego, CA) and 2-Methyl-2-(4,8,12-trimethyltridecyl)chroman-6-ol (tocol) was from Matreya Inc. (Pleasant Gap, PA).…”

Quantification of Tocopherols and Tocotrienols in Portuguese Olive Oils Using HPLC with Three Different Detection Systems

“…ELSD has been already successfully applied in the analysis of different compounds and consequently is increasingly used in many analytical laboratories (20,21). Although there are several methods reported allowing the simultaneous determination of tocopherols and tocotrienols (16,18,(22)(23)(24)(25), data concerning the tocotrienol composition of olive oils are still scarce (26,27).…”