Intended Use:

Fouchet’s reagent is used to detect Bilirubin (Bile) in urine.

Principle

For testing bilirubin in urine, two types of tests are available namely (A) Oxidation test-where bilirubin is oxidised to green biliverdin and (B) Diazotization test-where bilirubin is diazotised to a highly coloured compound. Fouchet’s reagent used in Fouchet’s test comes under oxidizing reagent or test. Barium chloride precipitates the sulphate radicals present in urine to form precipitate of barium sulphate. If bile pigments are present in urine, they adhere to these molecules. Ferric chloride present in Fouchet’s reagent then oxidises yellow bilirubin, in the presence of trichloroacetic acid to green biliverdin. Therefore, the development of green colour due to the formation of biliverdin indicates the presence of bilirubin(bile) in urine.