Studies on bile pigments

Abstract

A new test for bilirubin in urine has been described consisting in the adsorption of urinary pigments on a layer of talc and the production of blue bilicyanin by oxidation with a drop of Fouche''s reagent or 10% HNO3. The method described permits for the first time the detection of bilirubin in normal urine. The blue bilicyanin reaction in normal urine has been investigated with regard to the interference of indole compounds and has been found to be specific for bilirubin; excessive amts. of indican react only after about 30 min. The limits of detectability of pure bilirubin dissolved in weak NaOH, diluted alcohol and urine freed from preformed bilirubin are 6.0, 0.8, and 0.9 p.p.m. respectively. Quantitative estimation by means of a dilution technique gave a bilirubin content of approximately 0.3 mgm./100 ml. in normal urine and an output of about 5 mgm. bilirubin per day.