Materials
2,2,4-Trimethylpentane (isooctane), formic acid, p -anisidine,
4-methyl-1-pentanol, aluminum oxide (Brockman Grade 1), BHT, sand,
volatiles standards, ammonium thiocyanate, ferrous chloride, and food
grade mixed tocopherols (Toco) were purchased from Sigma–Aldrich (St.
Louis, MO, USA). According to the manufacturer’s report, Toco contained
74.0% total tocopherols including 13.2% α-, 0.16% β-, 42.9% γ-, and
16.3% δ-tocopherols in weight. A commercial rosemary extract (RE) was
generously provided by DuPont (Wilmington, DE, USA), which contained the
mono-diglycerides of fatty acids, acetic acid esters of mono- and
diglycerides of fatty acids, propylene glycol, 3.8-4.7% carnosic acid
and carnosol, and 4.0-4.7% phenolic diterpenes according to the product
description. Soybean oil (SBO) was purchased from a local grocery store.
Fish oil (FO) was purchased from Nordic Naturals (Watsonville, CA, USA).
Hexane, methanol, acetic acid, isopropanol, acetonitrile,
dichloromethane, and ethyl acetate were purchased from Fisher Scientific
(Fair Lawn, NJ, USA).