ANALYSIS OF TOTAL, GROUPED, AND INDIVIDUAL URINARY 17-KETOSTEROIDS: A CRITICAL EVALUATION

Abstract

ABSTRACT The complex origin of urinary 17-ketosteroids on the one hand, and the need for technical simplicity on the other, make it desirable to have available a series of analytical methods. In some circumstances it may be sufficient to obtain a simple overall measurement which is highly non-specific; in others it may be desirable to measure, with greater specificity and at the cost of greater complexity, the 11-deoxy and/or the 11-oxy ketosteroid moieties; in still other circumstances it may be important to assess the excretion of the individual ketosteroids with methods of high precision and specificity, but of proportionately greater technical complexity. Various procedures have been investigated, especially with respect to accuracy and specificity. Hydrolysis with perchloric acid in tetrahydrofuran produces the same extensive destruction found with other mineral acids. The Girard reaction greatly improves specificity but does not remove all spurious Zimmermann chromogens. Thin-layer chromatography does not insure complete colorimetric specificity either, and it is found to be a prerequisite for quantitative gas chromatography. GLC using chloromethyldimethyl silyl ethers and 5α-dihydrotestosterone as an internal standard provides excellent separation and quantitation of the 7 individual 17-ketosteroids. Extensive precautions are required with GLC methods (including this one) to find and eliminate contaminants which have the same retention time as steroids of interest; the problem of specificity, so well known with Zimmermann chromogens, is not eliminated by the use of GLC. A method is described for purification and group separation (11-oxy, 11-deoxy) of the 17-ketosteroids; this is followed by colorimetrie measurement of the groups or, after recombining them, by quantitative GLC analysis to measure the individual steroids.