A rapid method for the estimation of urinary 17-ketosteroids.

HE QUANTITATIVE ESTIMATION of the urinary 17-ketosteroids in the routine laboratory still presents a number of problems. The most serious of these is the presence of nonketonic chronlogens in tile final extracts prepared by the usual extraction methods. Tile removal of these interfering substances by tile application of Girard’s reagent (1, 2) is not feasible for the routine clinical laboratory. Repeated extraction with different solvents, charcoal decolorization (3), as well as the deduction of nonspecific absorption by reading the color at 420 m. and again at 520 m (4) are much too tinie consuming for everyday use. The methods of Masuda (5) and Kafka (5a) employing amyl acetate extraction of the color complex gives blank readings that are too high and inconsistent values, when different batches of the solvent are used. Empirical correction factors for deducting the interfering color absorption was found unreliable by various authors (6-7). Another drawback of the more widely used methods is the use of large volumes of urine extracted repeatedly with relatively small volumes of solvent, which is both time consuming and produces frequently cumbersome emulsions. Sulman (8) employs microamounts of urine in his method, but the nonspecific chromogens are not removed. This paper describes an adaptation of the method of Drekter (9) for hydrolysis and extraction using a small volume of urine extracted once only with a larger volume of ether. To the redissolved extract the Zimmerman (10) reaction is applied. The color due to the ketonic substances is selectively isolated by chloroform extraction from the