ANALYSIS OF STEROIDS .46. QUALITATIVE AND QUANTITATIVE CHARACTERIZATION OF BULK CHOLESTEROL BY GAS-CHROMATOGRAPHY AND GAS-CHROMATOGRAPHY MASS-SPECTROMETRY

Methods are described for the determination of the cholesterol (cholest-5-en-3beta-ol) content of crude and bulk cholesterol samples and the determination of their impurity profile. For both purposes capillary gas chromatography was used with phenylmethylsilicone gum as the stationary phase. The cholesterol contents of bulk samples obtained from ten different manufacturers ranged between 90.8 and 98.5%. The relative standard deviation of the method was 0.62%. In the course of the impurity profiling by gas chromatography-mass spectrometry, two major impurities were found in all samples: desmosterol (cholesta-5,24-dien-3beta-ol) and lathosterol (5alpha-cholest-7-en-3beta-ol). Some minor steroidal impurities were also detected.