Facile gas-liquid chromatographic resolution of saturated and unsaturated sterols using a polar capillary column

Plasma non-cholesterol sterols

Increased levels of plasma sterols other than cholesterol can serve as markers for abnormalities in lipid metabolism associated with clinical disease. Premature atherosclerosis and xanthomatosis occur in two rare lipid storage diseases, Cerebrotendinous xanthomatosis (CTX) and sitosterolemia. In CTX, cholestanol is present in all tissues. In sitosterolemia, dietary campesterol and sitosterol accumulate in plasma and red blood cells. Plasma accumulation of oxo-sterols is associated with inhibition of bile acid synthesis and other abnormalities in plasma lipid metabolism. Inhibition of cholesterol biosynthesis is associated with plasma appearance of precursor sterols. The increases in non-cholesterol sterols, while highly significant, represent only minor changes in plasma sterols, which require capillary gas-liquid chromatography and MS for effective detection, identification and quantification.

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

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 microg/ml and 0.2 microg/ml for sitostanol to 0.4 microg/ml and 1.2 microg/ml for campesterol and campestanol. Analytes were measured at concentrations of 120 ng/ml to 6 microg/ml with standard deviations of 0.02 to 0.12 microg/ml for 55 analyses of a control serum sample conducted over a 2-month period.