COLORIMETRIC DETERMINATION OF CRYSTALLINE AND URINARY KETOSTEROIDS CLINICAL USEFULNESS OF THIS METHOD12

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Abstract
An analysis of observations made with the Hardy recording spectrophotometer shows that identical colors are developed with crystalline androsterone and dehydroisoandrosterone by a modification of the Zimmermann''s m-dinitrobenzene reaction which is described herein. It is concluded from these curves that the intensity of color developed with this technic from a unit wt. of dehydroisoandrosterone is greater than that developed from a corresponding amt. of androsterone. The discs of the Oesting colorimeter have been calibrated with crystalline androsterone (123 detns.) and dehydroisoandrosterone (77 detns.) by this modification of the Zimmermann reaction. This colorimetric method of assay was applied to the quantitative estimation of androgens in 32 solns. containing known amts. of crystalline androsterone, in 30 specimens of urine from 3 normal [female][female] and in 169 specimens of urine from 23 patients with hirsutism and virilism. The accuracy to be expected with this method in the detn. of crystalline androsterone is usually within 10% of that present and the assay of the total daily urinary androgens is of value in the differential diagnosis of virilism, particularly in the presence of an adrenal cortical tumor. The total daily androgen excretion of normal [female][female], hirsute [female][female] and patients with frank virilism may fall within the same range, although the urinary androgens tend to be higher in the individuals of the latter group than among those of the other 2 groups. Certain practical considerations which led to the adoption of crystalline androsterone as a standard for the colorimetric assay of urinary androgens are included in the discussion of the applicability of the colorimetric method to the problems of clinical endocrinology. Because of the subjective errors inherent in visual colorimetry and because of the inaccuracies involved in the interpolation of intermediary disc values in the Oesting colorimeter, the photoelectric instrument is preferable for androgen assays. The Oesting colorimeter is entirely adequate for clinical purposes, however, if it is used in conjunction with the technic described.