Test-tube extraction method for the micro-determination of urinary 17-ketosteroids.

SIMPLE, RAPID TEST-TUBE EXIRACTION TECHNIC for the determination of urinary 17-ketosteroids has seen developed in our laboratories. A complete urinary 17-ketosteroid determination was carried out in a glass stoppered photometer cuvet by combining this extraction technic with a colorimetric method. Three colorimetric methods, Zimmermann (1), (2), Pincus (3), and Cohen and Kaluszyner (4) were compared using the test tube extraction technic. A modification of the extraction technic of Drekter et al. (5) was used in which choloroform was substituted for ether. The colorimetric method of Pincus (3) is not as popular as that of Zimmermann or the latter’s modification by Callow et al. (6) for the determination of 17-ketosteroids. This is unfortunate because of the many difilculties which have been experienced with the colorimetric Zimmermann reaction (7) such as; nonspecificity, sensitivity to the concentration of reagents, slow color development, instability of reagents, nonreproducibiity, light and temperature sensitivity, use of color corrections, etc., are avoided by use of the Pincus reaction (3). An objectionable defect of the Pincus reaction is the development of a weak color with dehydroisoandrosterone. However, this ketosteroid, normally constitutes about 10 per cent or less of the urinary 17-ketosteroids. The recently proposed 17-ketosteroid method of Cohen and Kaluszyner (4) in which 3, 5-dinitrobenzoic acid is substituted for m-dinitrobenzene gives results, which according to data obtained by these authors represent more accurately the true content