1. Fouchet's test:

Procedure-

1. To 10 ml bile, add 2 drops of saturated MgSO4 solution, 10 ml 10% BaCl2, boil, cool and filter. Yellow precipitates will form thereafter. Take the ppt out on a filter paper.
2. Add a drop of Fouchet’s reagent to the ppt on the filter paper. The ppt will turn blue or green.

Inference - Bile pigments absorbed on BaSO4 ppt are oxidized to coloured products by trichloroacetic acid and FeCl3 of Fouchet’s reagent.

Rothera’s test -

Procedure - Saturate 5 ml urine with ammonium sulphate crystals, then add 2 drops of fresh 5% sodium nitroprusside and 1 ml strong liquor ammonia slowly along the side of the tube. A purple ring will be observed.

Inference- Acetone or acetoacetic acid or both may be present (ketone bodies)

hello Shafiya!

Both Rothera test and the Fouchet test are done to find any abnormalities in urine sample. Rothera test is used to detect ketone molecules in the urine sample(acetone or acetoacetic acid). The presence of acetone is an indication of Diabetes-mellitus. The reagents used in this test consists of ammonium sulfate and sodium nitroprisside. The presence of acetones is marked by turning of solution to purple.

Fouchet test is a test used to detect bilirubin in urine. The reagent used is called Fouchet reagent which gives green color when the urine sample containing bilirubin is treated with it. The presence of bilirubin in urine is a dangerous indication of liver disease.

Hope this helps!