Dehydroisoandrosterone (definition in urine according to Ellen). From the ether extract obtained in the determination of 17-ketosteroids, 2 ml are taken to a standard tube, the ether is evaporated to dryness in a water bath at a temperature of 40-50 °, dried in a desiccator for 30-60 minutes, and 0.2 ml of a 95-degree of ethyl alcohol. The mixture is shaken and evaporated to dryness in a water bath at a temperature of 65-70 °. To the dry residue, add 2 ml of a mixture consisting of 20 ml of 90-degree ethanol and 80 ml of concentrated sulfuric acid (1: 4). The mixture is heated in a water bath at a temperature of 55 ° for 12 minutes, after which the tubes are transferred to cold water for 1 minute. Then 3 ml of 95% ethyl alcohol are poured into each tube, the mixture is shaken, left at room temperature for 1 hour and colorimetrically on a SF-1 spectrophotometer at 600 nm microrons (maximum absorption). In the presence of dehydroisoandrosterone, a purple-pink, purple-brown or violet color appears.
The amount of dehydroisoandrosterone is calculated from
where x is the amount of dehydroisoandrosterone in milligrams per day; A is the amount of dehydroisoandrosterone found by the calibration curve compiled experimentally for crystalline dehydroisoandrosterone; B is the total amount of the ether extract obtained by extraction of 17-ketosteroids; D - diuresis in milliliters; M is the amount of the ether extract taken to determine dehydroisoandrosterone; V - the amount of urine taken in the assay (25 ml); K is the conversion factor (equal to 2.35), derived from Ellen's formula, taking into account the correction of the optical density of crystalline dehydroisoandrosterone at different wavelengths (600, 640, 560 mm).
Normally, 0.8-1 mg of dehydroisoandrosterone is excreted per day with urine.