»MICRO-METHODS« FOR THE DETERMINATION OF 17-KETOSTEROIDS IN URINE

Abstract

A method for the detn. of total urinary 17-ketosteroids with small samples is descr. An amt. of urine equal to 1/50 of the 24-hr. urine specimen is used. 10 vol. % of a 40% H2SO4 soln. is added. Hydrolysis and extraction may be done successively or combined. For the extraction, ether or benzene is preferred to CCl4. The non-specific chromogens and phenols are removed by successive extraction with NaHCO3, 2[image] NaOH and water. After drying with dehydrated Na2SO4, the benzene extract is filtered and evaporated to dryness over a boiling waterbath under reduced pressure. The residue is taken up with 0.8 ml. absolute alcohol. The color reaction is made in duplicate using 0.2 ml. of the material, and the amt. is detd. with a photometer. The values thus obtained were compared with those after the standard method had been used. The micro-method was found to be as reliable as the standard method and even more accurate where small amts. of 17-ketosteroids were found. No real difference was found between the benzene and ether extraction methods. The above statements are supported by statistical treatment of the data by G. Rasch.