Rapid methods for the determination of pregnanediol in urine.

A LTHOUGH MANY METHODS have been published for the determination of pregnanediol in urine, we found none of them fully satisfactory. The first gravimetric method (1), and colorimetric methods derived from this one (2, 3), are rather unspecific, because, especially under pathologic conditions, fairly large amounts of similar compounds are found in the so-called pregnanediol fraction. Determination of unconjugated pregnanediol was described by several authors (4-6) and although these methods are rather useful, they are very laborious and require highly skilled technicians. The imitroductiomi of chromatography led to many improved procedures amomig which the methods of Klopper et al. (7) and Goldzieher and Nakamura (8) are most widely used. In the first method (7), pregrianediol is liberated by acid hydrolysis and the toluene extract purified by alkaline and permanganate washings; after double adsorption chromatography on alumina columns and acetylation of the steroids, the filial determination is domme spectrophotometrically after a reaction with sulfuric acid. Quamititation requires the application of Allen’s correction (9). The results are satisfying, but the method is laborious. The second method (8), using enzymatic hydrolysis and silica-gel chromatography, is slightly more sensitive, using as a final reagent sulfuric acid saturated with sulfur dioxide. An excellent study on the specificity of the sulfuric acid reaction was published by Henry and Thevenet (10), who also developed a detection method for pregnanetriol and pregnanediolone. This method, which is