Precise quantitative determination of phytosterols, stanols, and cholesterol metabolites in human serum by capillary gas-liquid chromatography.

Abstract Total lipid extraction, solid-phase extraction, saponification, derivatization to trimethylsilyl ether derivatives, then capillary gas–liquid chromatography were used for quantitative analysis of sitosterol, campesterol, stigmasterol, sitostanol, campestanol, lathosterol, desmosterol, and lanosterol in human serum. Details of quality control integral to the accuracy and precision of analyses are included. The method limits of detection and quantitation, respectively, ranged from 0.05 μg/ml and 0.2 μg/ml for sitostanol to 0.4 μg/ml and 1.2 μg/ml for campesterol and campestanol. Analytes were measured at concentrations of 120 ng/ml to 6 μg/ml with standard deviations of 0.02 to 0.12 μg/ml for 55 analyses of a control serum sample conducted over a 2-month period.