| Abstrakt: |
Steroids consist of an essentially lipophilic (or hydrophobic, non-polar) cyclopentanoperhydrophenanthrene nucleus modified on the periphery of the nucleus or on the side chain by the addition of hydrophilic (or lipophobic, polar) groups. Although steroids are widely distributed in nature and many thousands have been synthesised in the laboratories of pharmaceutical and chemical organisations, this chapter concentrates primarily on the methodology for the analysis of steroids of biological importance to human subjects and in particular on the methods for the analysis of the very low concentrations of steroids found in human biological tissues or formed during in vitro or in vivo studies. This does not, however, imply that the techniques discussed here may not find applicability in other areas of steroid analysis. This chapter neither discusses specifically the saturation analysis techniques including immunoassay-radioimmunoassay (RIA), enzymeimmunoassay (EIA), which are explained in Chapter 4, nor the analysis of cardenolides, sapogenins, alkaloids, brassinosteroids or ecdysteroids, which present their own analytical challenges but are of less interest in a clinical context. Further details on basic principles of mass spectrometry (MS) are discussed in Chapter 2. [ABSTRACT FROM AUTHOR] |
