Use of a new silylating agent for separation of bile acids and cholesterol by selected ion monitoring with the computer controlled intensity matching technique.

Dimethylethylsilyl ether derivatives of human biliary bile acid ethyl esters and cholesterol were separated completely by gas chromatography and selected ion monitoring by use of the mixed stationary liquid phase of OV-101 and Dexsil 300GC (1:1). These derivatives could be prepared easily and subjected directly to gas chromatography mass spectrometry. Dimethylethylsilyl ethers of bile acids ethyl esters were eluted in regular order according to the number of hydroxyl groups when used with the non-polar stationary liquid phases. Lithocholic acid, a minor component of human bile, was identified easily by selected ion monitoring with the computer controlled intensity matching technique.