The Froehde reagent is used as a simple spot-test to presumptively identify
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 ...
, especially
opioids
Opioids are substances that act on opioid receptors to produce morphine-like effects. Medically they are primarily used for pain relief, including anesthesia. Other medical uses include suppression of diarrhea, replacement therapy for opioid use ...
, 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 ( Commonwealth spelling), known in antiquity as oil of vitriol, is a mineral acid composed of the elements sulfur, oxygen and hydrogen, with the molecular formu ...
, 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 federal executive department of the United States government tasked with the enforcement of federal law and administration of justice in the United State ...
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 found as the dihydrate, Na2MoO4·2H2O.
The molybdate(VI) anion is tetrahedral. Two sodium cations coordinate with every one anion.Braithwaite, E. ...
or molybdic acid.
The Virginia Department of Forensic Science method uses 0.5 g
ammonium molybdate Ammonium molybdate can refer to:
*Ammonium orthomolybdate, (NH4)2MoO4
*Ammonium heptamolybdate, (NH4)6Mo7O24, usually encountered as the tetrahydrate
* Ammonium phosphomolybdate, (NH4)3PMo12O40
*Ammonium tetrathiomolybdate, (NH4)2MoS4 this chemical ...
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
*
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 reduce the harm from drug consumption by allowing users to find out the content and purity of substances that they intend to consume. This empowers users to make safer choices: to avoid more dangerous substa ...
*
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 g ...
*
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 The Liebermann reagent named after Hungarian chemist Leo Liebermann (1852-1926) is used as a simple spot-test to presumptively identify alkaloids as well as other compounds. It is composed of a mixture of potassium nitrite and concentrated sulfuri ...
*
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 ...
*
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 St ...
*
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 ...
*
Simon's reagent
Simon's reagent is used as a simple spot-test to presumptively identify alkaloids as well as other compounds. It reacts with secondary amines like MDMA and methamphetamine to give a blue solution.
Uses
The primary use of this reagent is for dete ...
*
Zwikker reagent The Zwikker reagent is used as a simple spot-test to presumptively identify barbiturates. It is composed of a mixture of two solutions. Part A is 0.5 g of copper (II) sulfate in 100 ml of distilled water. Part B consists of 5% pyridine (v/v) in ch ...
References
Chemical tests
Analytical reagents
Drug testing reagents
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