The Froehde reagent 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 ...
, especially
opioids
Opioids are a class of Drug, drugs that derive from, or mimic, natural substances found in the Papaver somniferum, opium poppy plant. Opioids work on opioid receptors in the brain and other organs to produce a variety of morphine-like effects, ...
, as well as other compounds. It is composed of a mixture of
molybdic acid
Molybdic acid refers to hydrated forms of molybdenum trioxide and related species. The monohydrate (MoO3·H2O) and the dihydrate (MoO3·2H2O) are well characterized. They are yellow diamagnetic solids.
Structure of the solids
Solid forms of mo ...
or a molybdate salt dissolved in hot, 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, ...
, which is then dripped onto the substance being tested.
The
United States Department of Justice
The United States Department of Justice (DOJ), also known as the Justice Department, is a United States federal executive departments, federal executive department of the U.S. government that oversees the domestic enforcement of Law of the Unite ...
method for producing the reagent is the addition of 100 ml of hot, concentrated (95–98%) sulfuric acid to 0.5 g of
sodium molybdate
Sodium molybdate, Na2MoO4, is useful as a source of molybdenum. This white, crystalline salt is often encountered as the dihydrate, Na2MoO4·2H2O.
Preparation
Dissolution of MoO3 in sodium hydroxide at 50–70 °C followed by crystallizing t ...
or molybdic acid.
The Virginia Department of Forensic Science method uses 0.5 g
ammonium molybdate per 100 ml
H2SO4 (conc.)
Unheated sulfuric acid can be used to prepare the reagent in a less dangerous manner, but 2–4 hours must be allowed for the molybdate to dissolve.
See also
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Reagent testing
Reagent testing is one of the processes used to identify substances contained within a pill, usually illicit substances.
With the increased prevalence of drugs being available in their pure forms, the terms "drug checking" or "pill testing" may a ...
*
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 ...
*
Dille–Koppanyi reagent
*
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 ...
*
Liebermann reagent
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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
*
Mecke reagent
*
Simon's reagent
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Zwikker reagent
References
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Chemical tests
Analytical reagents
Drug testing reagents