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Test for; Alkaloid, Tannins, Flavonoids, Coumarins, and Glycosides
Accepted Answer
Test for Alkaloids
- Mayer's Test: Add a few drops of Mayer's reagent (potassium mercuric iodide solution) to the test solution. A white or cream-colored precipitate indicates the presence of alkaloids.
- Wagner's Test: Add a few drops of Wagner's reagent (iodine in potassium iodide solution) to the test solution. A reddish-brown precipitate indicates the presence of alkaloids.
- Dragendorff's Test: Add a few drops of Dragendorff's reagent (potassium bismuth iodide solution) to the test solution. An orange or red precipitate indicates the presence of alkaloids.
Test for Tannins
- Ferric Chloride Test: Add a few drops of ferric chloride solution to the test solution. A dark blue or black color indicates the presence of tannins.
- Lead Acetate Test: Add a few drops of lead acetate solution to the test solution. A white or cream-colored precipitate indicates the presence of tannins.
Test for Flavonoids
- Shinoda Test: Add a few drops of concentrated hydrochloric acid and a few pieces of magnesium turnings to the test solution. A pink or red color indicates the presence of flavonoids.
- Sodium Hydroxide Test: Add a few drops of sodium hydroxide solution to the test solution. A yellow color indicates the presence of flavonoids.
Test for Coumarins
- Fehling's Test: Add a few drops of Fehling's reagent A and Fehling's reagent B to the test solution. A reddish-brown precipitate indicates the presence of coumarins.
- Borntrager's Test: Add a few drops of concentrated sulfuric acid and a few drops of potassium permanganate solution to the test solution. A purple color indicates the presence of coumarins.
Test for Glycosides
- Molisch's Test: Add a few drops of Molisch's reagent (alpha-naphthol in ethanol) and a few drops of concentrated sulfuric acid to the test solution. A purple or red ring indicates the presence of glycosides.
- Benedict's Test: Add a few drops of Benedict's reagent (copper sulfate in sodium citrate solution) to the test solution. A green, yellow, or red precipitate indicates the presence of reducing sugars, which may be glycosides.
- Mayer's Test: Add a few drops of Mayer's reagent (potassium mercuric iodide solution) to the test solution. A white or cream-colored precipitate indicates the presence of alkaloids.
- Wagner's Test: Add a few drops of Wagner's reagent (iodine in potassium iodide solution) to the test solution. A reddish-brown precipitate indicates the presence of alkaloids.
- Dragendorff's Test: Add a few drops of Dragendorff's reagent (potassium bismuth iodide solution) to the test solution. An orange or red precipitate indicates the presence of alkaloids.
Test for Tannins
- Ferric Chloride Test: Add a few drops of ferric chloride solution to the test solution. A dark blue or black color indicates the presence of tannins.
- Lead Acetate Test: Add a few drops of lead acetate solution to the test solution. A white or cream-colored precipitate indicates the presence of tannins.
Test for Flavonoids
- Shinoda Test: Add a few drops of concentrated hydrochloric acid and a few pieces of magnesium turnings to the test solution. A pink or red color indicates the presence of flavonoids.
- Sodium Hydroxide Test: Add a few drops of sodium hydroxide solution to the test solution. A yellow color indicates the presence of flavonoids.
Test for Coumarins
- Fehling's Test: Add a few drops of Fehling's reagent A and Fehling's reagent B to the test solution. A reddish-brown precipitate indicates the presence of coumarins.
- Borntrager's Test: Add a few drops of concentrated sulfuric acid and a few drops of potassium permanganate solution to the test solution. A purple color indicates the presence of coumarins.
Test for Glycosides
- Molisch's Test: Add a few drops of Molisch's reagent (alpha-naphthol in ethanol) and a few drops of concentrated sulfuric acid to the test solution. A purple or red ring indicates the presence of glycosides.
- Benedict's Test: Add a few drops of Benedict's reagent (copper sulfate in sodium citrate solution) to the test solution. A green, yellow, or red precipitate indicates the presence of reducing sugars, which may be glycosides.
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