The Liebermann reagent named after Hungarian chemist
Leo Liebermann (1852-1926) is used as a simple spot-test to presumptively identify
alkaloids
Alkaloids are a broad class of naturally occurring organic compounds that contain at least one nitrogen atom. Some synthetic compounds of similar structure may also be termed alkaloids.
Alkaloids are produced by a large variety of organisms i ...
as well as other compounds. It is composed of a mixture of
potassium nitrite
Potassium nitrite (distinct from potassium nitrate) is the inorganic compound with the chemical formula . It is an ionic salt of potassium ions K+ and nitrite ions NO2−, which forms a white or slightly yellow, hygroscopic crystalline powder that ...
and concentrated
sulfuric acid
Sulfuric acid (American spelling and the preferred IUPAC name) or sulphuric acid (English in the Commonwealth of Nations, Commonwealth spelling), known in antiquity as oil of vitriol, is a mineral acid composed of the elements sulfur, oxygen, ...
.
1 g of potassium nitrite is used for every 10 mL of sulfuric acid. Potassium nitrite may also be substituted by
sodium nitrite
Sodium nitrite is an inorganic compound with the chemical formula . It is a white to slightly yellowish crystalline powder that is very soluble in water and is hygroscopic. From an industrial perspective, it is the most important nitrite sa ...
.
It is used to test for
cocaine
Cocaine is a tropane alkaloid and central nervous system stimulant, derived primarily from the leaves of two South American coca plants, ''Erythroxylum coca'' and ''Erythroxylum novogranatense, E. novogranatense'', which are cultivated a ...
,
morphine
Morphine, formerly also called morphia, is an opiate that is found naturally in opium, a dark brown resin produced by drying the latex of opium poppies (''Papaver somniferum''). It is mainly used as an analgesic (pain medication). There are ...
,
PMA and
PMMA.
The test is performed by scraping off a small amount of the substance and adding a drop of the reagent (which is initially clear and colorless). The results are analyzed by viewing the color of the resulting mixture, and by the time taken for the change in color to become apparent.
See also
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Drug checking
Drug checking or pill testing is a way to Harm reduction, reduce the harm from drug consumption by allowing users to find out the content and purity of substances that they intend to consume. This enables users to make safer choices: to avoid more ...
*
Liebermann–Burchard test
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Dille–Koppanyi reagent The Dille–Koppanyi reagent is used as a simple spot-test to presumptively identify barbiturates. It is composed of a mixture of two solutions. Part A is 0.1 g of cobalt(II) acetate dihydrate dissolved in 100 ml of methanol mixed with 0.2 ml of gl ...
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Folin's reagent
Folin's reagent or sodium 1,2-naphthoquinone-4-sulfonate is a chemical reagent used as a derivatizing agent to measure levels of amines and amino acids. The reagent reacts with them in alkaline solution to produce a fluorescent material that can ...
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Froehde reagent
The Froehde reagent is used as a simple spot-test to presumptively identify alkaloids, especially opioids, as well as other compounds. It is composed of a mixture of molybdic acid or a molybdate salt dissolved in hot, concentrated sulfuric acid, wh ...
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Mandelin reagent The Mandelin reagent is used as a simple spot-test to presumptively identify alkaloids as well as other compounds. It is composed of a mixture of ammonium metavanadate and concentrated sulfuric acid. Its primary use is for the detection of ketamine ...
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Marquis reagent
Marquis reagent is used as a simple spot-test to presumptively identify alkaloids as well as other compounds. It is composed of a mixture of formaldehyde and concentrated sulfuric acid, which is dripped onto the substance being tested. The United ...
*
Mecke reagent
The Mecke reagent is used as a simple spot-test to presumptively identify alkaloids as well as other compounds. It is composed of a mixture of selenous acid and concentrated sulfuric acid, which is dripped onto the substance being tested.
The Unit ...
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Simon's reagent
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Zwikker reagent
References
{{Reflist
Chemical tests
Analytical reagents
Drug testing reagents