Gas chromatography of dimethylalkylsilyl ether derivatives of bile acid methyl esters

The gas chromatographic separation of the DMAS ether derivatives of ten bile acid methyl esters, namely DMES, DMnPS and DMiPS ethers, have been studied by use of an open tubular glass capillary column, coated with SE-30. The DMAS ether derivatives were eluted in sequence according to the number of hydroxyl groups except of 12-KCDCA, and separated. This contrasts with the poorly resolved gas chromatographic peaks produced by the TMS ether derivatives. The DMES ether derivatives were resolved and baseline separation in 30 min, but those of HCA and 12-KCDCA had similar methylene unit values.