Abstract: Oxidation of cholesterol in the presence of air during heating was studied.In the heated cholesterol preparations,cholesterol oxidation products were separated and detected by capillary column gas chromatography.When cholesterol was heated at 90℃ for 2h or at higher temperature in a short time,virtually no detectable oxidized cholesterol was produced.However,cholesterol was readily oxidized at high temperature in a relatively long time.Six cholesterol oxidation products including 5,6α-epoxycholesterol,5,6β-epoxycholesterol,cholestan-3β,5α,6β-triol,7-ketocholesterol,25-hydroxycholesterol,and 6-ketocholesterol were detected.The range of individual cholesterol oxidation products varied from 0.004% to 0.6860% cholesterol.Among them,7-ketocholesterol was the most predominant products.The composition of cholesterol oxidation products differed on different heating temperature、time and amount of cholesterol.

Key words: Cholesterol oxidation products , Cholesterol , Capillary gas chromatography