Artifactual oxidation of cholesterol during the analysis of cholesterol oxidation products: Protective effect of antioxidants

To study the influence of the addition of various antioxidants and their combinations on the artifactual oxidation of cholesterol during analysis, 2 factorial experiments were performed in duplicate. In the first experiment, 2 amounts of the following antioxidants were assayed: ethylenediaminetetraacetic acid (EDTA) disodium salt (0 and 1 mg), pyrogallol (0 and 600 mug), and butylated hydroxytoluene (BHT, 0 and 600 mug); in the second, EDTA disodium salt (0 and 1 mg), ascorbyl palmitate (0 and 600 mug), and BHT (0 and 600 mug). Under low oxidative conditions of dim light, evaporation of solvents at low temperatures, anti cold saponification in darkness under nitrogen atmosphere, the addition of antioxidants showed no further protective effect. Furthermore, the presence of ascorbyl palmitate significantly increased the formation of cholesterol-5beta,6beta-epoxide, and 7beta-hydroxycholesterol.