Determination of Cholesterol by Digitonin-Method and Thin-Layer Chromatography

Experiments were carried out in order to elucidate the conditions for the quantitative analysis of cholesterol by thin-layer chromatography (TLC) and to compare the quantitative values of TLC with those of digitonin-method.The pure cholesterol refined by column chromatography was used as the standard sample for the calibration curve of TLC.Silica gel G and silica gel G-10% AgNO3 for the stationary phase were suited to the determination of cholesterol by TLC. Activation temperatures, activation times, developing solvents, detection agents, charring times and standing times after charring were examined with the both stationary phases.In the determination of cholesterols by TLC with silica gel G· and silica gel G-10% AgNO3·plate, the purities of cholesterol in sample 2 was 99.2% 99.1% and that in sample 3 was 97.3% respectively. Their purities described before agreed nearly in both methods. The data of standard deviation showed in the range of 0.670.70% and 0.830.90% respectively.It was found that values in the determination of these cholesterols (sample 2 and 3) by digitonin-method were slighty higher than those obtained by TLC.Solubilities of cholesterol-digitonide for 95% ethanol in range of 15.025.0°C were measured. The value obtained was in good agreement with the data of Windaus at 18.0°C. The solubility described before was used in order to correct the purities of the cholesterols.