Mayer's reagent is an alkaloidal precipitating reagent used for the detection of

alkaloids Alkaloids are a class of basic, naturally occurring organic compounds that contain at least one nitrogen atom. This group also includes some related compounds with neutral and even weakly acidic properties. Some synthetic compounds of similar ...

in natural products. Mayer's reagent is freshly prepared by dissolving a mixture of

mercuric chloride Mercury(II) chloride (or mercury bichloride, mercury dichloride), historically also known as sulema or corrosive sublimate, is the inorganic chemical compound of mercury and chlorine with the formula HgCl2. It is white crystalline solid and is ...

(1.36 g) and of

potassium iodide Potassium iodide is a chemical compound, medication, and dietary supplement. It is a medication used for treating hyperthyroidism, in radiation emergencies, and for protecting the thyroid gland when certain types of radiopharmaceuticals are us ...

(5.00 g) in water (100.0 ml). Most alkaloids are precipitated from neutral or slightly acidic solution by Mayer’s reagent ( potassiomercuric iodide solution) to give a cream coloured precipitate. This test was invented by the German Chemist,

Julius Robert Von Mayer Julius Robert von Mayer (25 November 1814 – 20 March 1878) was a German physician, chemist, and physicist and one of the founders of thermodynamics. He is best known for enunciating in 1841 one of the original statements of the conservation ...

(1814–1878).

References

Potassium compounds Mercury(II) compounds Alkaloids Chemical tests Drug testing reagents {{chemistry-stub