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).