Abstract
SUMMARY: 1. Pregnane-3α:17α:20-triols give a blue fluorescent spot after heating a chromatogram sprayed with approximately 25% trichloracetic acid in ethanol. A spot containing 2 μg may be detected by this reaction. Out of forty-eight steroids examined only atiocholanediol gave a similar fluorescence. Certain other steroids give different characteristic colours and fluorescence. 2. The test has been successfully used to detect pregnanetriol in the non-ketonic fraction of urine extracts from a normal male and from a patient with adrenal hyperplasia. It has been used to detect the production of pregnanetriol by in vitro reduction of pregnane-3α:17α-diol-20-one. 3. The identity of the substances which gave this reaction and which were obtained from urine and from in vitro reduction was confirmed by isolation and characterization.