A Rapid Gas-Liquid Chromatographic Method for the Multidetermination of Antioxidants in Fats, Oils, and Dried Food Products

Abstract
A rapid quantitative method for determining 8 antioxidants in various food products is described. Two procedures are employed. The first involves the use of a glass wool precolumn to separate 3(2)-tert-butyl-4-hydroxyanisole, 3,5-di -tert - butyl - 4 - hydroxytoluene, 4 - hydroxymethyl- 2,6-di-tert-butylphenol, and mono-tertbutylhydroquinone (TBHQ) from nonvolatile residues resulting from direct injection of diluted sample or sample extracts into the gasliquid chromatographic (GLC) column. In the second procedure, the antioxidants TBHQ, 3,3'- thiodipropionic acid, n-propyl gallate, 2,4,5- trihydroxybutyrophenone, and nordihydroguaiaretic acid are isolated from food products by extraction with 70% ethanol. The antioxidant residues are then converted to trimethylsilyl derivatives, and determined by GLC, using a flame ionization detector. Recoveries of all 8 antioxidants from 28 food samples fortified at either 10 or 100 ppm ranged from 70 to 105%.