Mayer's reagent is an alkaloidal precipitating
reagent
In chemistry, a reagent ( ) or analytical reagent is a substance or compound added to a system to cause a chemical reaction, or test if one occurs. The terms ''reactant'' and ''reagent'' are often used interchangeably, but reactant specifies a ...
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 st ...
in natural products. Mayer's reagent is freshly prepared by dissolving a mixture of
mercuric chloride (1.36 g) and of
potassium iodide (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 (1814–1878).
References
Potassium compounds
Mercury(II) compounds
Alkaloids
Chemical tests
Drug testing reagents
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