Authors:Á. Kovács, R. Dulicsek, L. Varga, J. Szigeti, and Z. Herpai
): Determination of cholesterol oxides in dairy products. Effect of storage conditions. J. agric. Fd Chem. , 45 , 4318-4323.
Determination of cholesterol oxides in dairy products. Effect of storage conditions
Authors:A. Alizadeh, M.R. Ehsani, and L. Rofehgarinejad
, D.J. , Botsoglou , A. & Psomas , I.E. ( 1998 ): Rapid determination of cholesterol in milk and milk products by direct saponification and capillary gas chromatography . J. Dairy Sci. , 81 , 2833 – 2840
Authors:L. Peng, X. Jiangjun, M. Fangquan, L. Xi, and Z. Chaocan
The standard molar enthalpy of combustion of cholesterol was measured at constant volume. According to value of ΔrUmθ(−14358.4±20.65 kJ mol−1), ΔrHmθ(−14385.7 kJ mol−1) of combustion reaction and ΔfHmθ(2812.9 kJ mol−1) of cholesterol were obtained from the reaction equation. The enthalpy of combustion reaction of cholesterol was also estimated
by the average bond enthalpies. By design of a thermo-chemical recycle, the enthalpy of combustion of cholesterol were calculated
between 283.15∼373.15 K. Besides, molar enthalpy and entropy of fusion of cholesterol was obtained by DSC technique.
Authors:M. Czauderna, M. Marounek, D. Duskova, and J. Kowalczyk
A method for determining underivatized cholesterol and its oxygen derivatives (ChlOs) in animal tissue specimens and some food has been developed using capillary gas chromatography (GC) and mass spectrometry (MS) with 5α-cholestane as the internal standard. The analysis preparation procedure for cholesterol and ChlOs consisted of lipid extraction followed by gentle saponification using 2 M KOH in ethanol. The analyzed samples were saponified overnight at room temperature in the dark with shaking. Then, free cholesterol and ChlOs were extracted using diethyl ether. The extracts were dried under argon, and the residues were redissolved in chloroform before GC-MS analysis. Cholesterol was analyzed in biological materials using the short column temperature program. The simultaneous quantification of cholesterol and its oxides in biological materials was performed using the longer column temperature program. Cholesterol was eluted faster than ChlOs. The chromatographic method that used column temperature program A can be successfully used for the simple and rapid quantification of cholesterol in biological materials, while the method using column temperature program B is more suitable for the simultaneous quantification of cholesterol and its oxides in biological materials.