Thin-Layer and Glass Fiber Paper Chromatography

Thin-Layer and Glass Fiber Paper Chromatography 

Sometimes the methyl esters are better separated than the free bile acids. This is especially true when neutral solvents are used. In acidic solvents the difference is small, particularly with trisubstituted bile acids. Thus, the same types of acidic solvents can be used for free and methylated bile acids. When bile acid methyl esters are acetylated or converted into trimethylsilyl ethers their mobility is considerably increased. The separation of configurational isomers is then often impaired whereas the separation of positional isomers may be improved (4). This is often the case when neutral derivatives are analyzed in neutral solvent systems (12). The influence of the nature and position of nuclear substituents on the mobility of a bile acid can be estimated 

In this particular solvent mobilities are given relative to that of deoxycholic acid (cf. Tables VII and VIII). This solvent is also used for conjugated bile acids (see Table IV). 

In this solvent mobilities are given relative to that of methyl allocholate. 

With this solvent Anasil 13 is used as adsorbent. 

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A. Thin-Layer and Glass Fiber Paper Chromatography... 

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