Group separation and gas chromatography--mass spectrometry of conjugated steroids in plasma.

A method is described for analysis of metabolic profiles of conjugated steroids in plasma. Steroids are extracted by Amberlite XAD-2 or Sep-Pak C18 cartridges at 60 64 C in the presence of triethylamine sulphate and separated into unconjugated neutral and phenolic compounds, glucuronide, monosulphate and disulphate conjugate groups by chromatography on the lipophilic strong anion exchanger triethylaminohydroxypropyl Sephadex LH-20 (TEAP-LH-20). The conjugate moiety is hydrolyzed by brief enzymatic or solvolytic procedures and released steroids are separated into a neutral and a phenolic fraction on TEAP-LH-20. The O-methyloxime and trimethylsilyl ether derivatives of the steroids are analyzed by glass capillary column gas liquid chromatography and gas chromatography mass spectrometry. Examples of the application of the method to analysis of conjugated steroids in plasma from pregnant women are given.