Find out a qualitative test for proteins, fats and oils, amino acids and test any fruit juice, saliva, sweat and urine for them.
(a) Test for protein
Biuret’s test – If Biuret’s reagent is added to protein, then the colour of the reagent changes from light blue to purple.
(b) Test for fats and oils
Grease or solubility test
(c) Test for amino acid
Ninhydrin test – If Ninhydrin reagent is added to the solution, then the colourless solution changes to pink, blue, or purple, depending on the amino acid.