Alkaloids are a group of naturally occurring chemical compounds that contain mostly basic nitrogen atoms. This group also includes some related compounds with neutral and even weakly acidic properties. Also some synthetic compounds of similar structure are attributed to alkaloids. In addition to carbon, hydrogen and nitrogen, alkaloids may also contain oxygen, sulfur and more rarely other elements such as chlorine, bromine, and phosphorus.
Test for alkaloids
1. Dragendorff’s test
1 ml of extract, add 1 ml of Dragendroff’s reagent (potassium bismuth iodide solution). An orange-red precipitate indicates the presence of alkaloids.
2.Mayer’s test
1 ml of extract, add 1 ml of Mayer’s reagent (potassium mercuric iodide solution). Whitish or cream colored precipitate indicates the presence of alkaloids.
3.Hager’s test
1 ml of extract, add 3 ml of Hager’s reagent (saturated aqueous solution of picric acid). Yellow colored precipitate indicates the presence of alkaloids
4. Wagner’s test
1 ml of extract, add 2 ml of Wagner’s reagent (iodine in potassium iodide). Reddish brown colored precipitate indicates the presence of alkaloids
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Test for alkaloids : Dragendorff’s test