How is the presence of alkaloid detected in sample?
Qualitative Chemical Tests for Alkaloids
① Dragendorff’s Test:
Reagent: Dragendorff’s reagent (potassium bismuth iodide solution)
Procedure:
Take 2-3 mL of the alkaloid solution.
Add a few drops of Dragendorff’s reagent to the sample.
Observe the color change.
Reaction: Alkaloid + Dragendorff’s reagent → Orange-brown precipitate
Results: An orange-brown precipitate confirms the presence of alkaloids.
② Mayer’s Test:
Reagent: Mayer’s reagent (potassium mercuric iodide solution)
Procedure:
Take 2-3 mL of the alkaloid solution.
Add a few drops of Mayer’s reagent to the sample.
Observe the color change.
Reaction: Alkaloid + Mayer’s reagent → White precipitate
Results: A white precipitate indicates the presence of alkaloids.
③ Hager’s Test:
Reagent: Hager’s reagent (saturated solution of picric acid)
Procedure:
Take 2-3 mL of the alkaloid solution.
Add a few drops of Hager’s reagent to the sample.
Observe the color change.
Reaction: Alkaloid + Hager’s reagent → Yellow precipitate
Results: A yellow precipitate confirms the presence of alkaloids.
④ Wagner’s Test:
Reagent: Wagner’s reagent (iodine potassium iodide solution)
Procedure:
Take 2-3 mL of the alkaloid solution.
Add a few drops of Wagner’s reagent to the sample.
Observe the color change.
Reaction: Alkaloid + Wagner’s reagent → Reddish-brown precipitate
Results: A reddish-brown precipitate confirms the presence of alkaloids.
