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 States Department of Justice method for producing the reagent is the addition of 100 mL of concentrated (95–98%) sulfuric acid to 5 mL of 40% formaldehyde.[1]:12 Different compounds produce different color reactions. Methanol may be added to slow down the reaction process to allow better observation of the colour change.
It was first discovered in 1896[2] and described by the Russian (Estonian) pharmacologist, Eduard Marquis (1871–1944) (Russian: Эдуард Маркус)[3] in his magister dissertation in 1896;[4] and named after him,[5] and was tested for the first time at the University of Dorpat. The reagent should be stored in the freezer for maximum shelf life[6]
It is the primary presumptive test used in Ecstasy testing kits. It can also be used to test for such substances as opiates (e.g. codeine, heroin), and phenethylamines (e.g. 2C-B, mescaline).
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:
Results
Reagent test results develop very quickly and due to reactions with moisture and oxygen in air, any changes after the first 60 seconds should be discarded.[7]
| Substance | Color | Time (s) | Notes |
|---|---|---|---|
| MDMA or MDA | purple to black | 0–5 | May have dark purple tint |
| Amphetamine, or methamphetamine | orange to brown | 0–5 | May have a brown tint |
| 2C-B | yellow to green | 5–10 | Color may change from initial result[7] |
| DXM | gray to black | 15–30 | Initially no change; takes much longer to reach black than MDMA |
| Substance | Color |
|---|---|
| βk-2C-B | Bright orange |
| 2C-B | Green-yellow |
| 2C-I | Green-yellow |
| 2,5-Dimethoxy-4-bromoamphetamine (DOB) | Olive green – yellow |
| 2-FMA | Rapidly fizzes and dissolves. Colourless/light yellow |
| 25I-NBOMe | Orange |
| 25C-NBOMe | Clear, Transparent |
| 25B-NBOMe | Dark green |
| 4F-MPH | Transparent, no reaction |
| 5-EAPB | Purple to black |
| 5-MeO-MiPT | Clear/light brown[9] |
| Aspirin | Pink > deep red[10][11][12] |
| Adrafinil | Deep reddish orange – dark reddish brown |
| Benzphetamine | Deep reddish brown |
| Benzylpiperazine(BZP) | Clear (fizzes) |
| Buprenorphine | Pinkish violet |
| Butylone | Yellow[8] |
| Chlorpromazine | Deep purplish red |
| Codeine | Very dark purple |
| Caffeine | Transparent, no change |
| Cocaine | Transparent, no change |
| d-Amphetamine | Strong reddish orange – dark reddish brown |
| d-Methamphetamine | Deep reddish orange – dark reddish brown |
| Diacetylmorphine (Heroin) | Deep purplish red |
| Dimethoxy-4-amylamphetamine (DMAA) | No color change (fizzes) |
| Dimethyltryptamine (DMT) | Orange |
| Diphenhydramine (DPH) | Yellow/orange > brown[13] |
| Dimethoxymethamphetamine HCL (DMMA) | Moderate olive |
| Doxepin | Blackish red |
| Dristan | Dark grayish red |
| Exedrine | Dark red |
| LSD | Olive black |
| Methoxetamine | Slow pink[8] |
| 3,4-Methylenedioxyamphetamine (MDA) | Dark purple – black |
| Methylenedioxy-N-ethylamphetamine (MDEA) | Dark purple – black |
| Methylenedioxymethamphetamine (MDMA) | Dark purple – black |
| Methylenedioxypropylamphetamine (MDPR) | Dark purple – black |
| Methylone (M1/bk-MDMA/MDMC) | Yellow |
| Methylenedioxypyrovalerone (MDPV) | Yellow |
| Pethidine/Meperidine | Deep brown |
| Mescaline | Strong orange |
| Methadone | Light yellowish pink |
| Methylphenidate | Moderate orange yellow |
| Methylene Blue | Dark green |
| Modafinil | Yellow/orange – brown[14] |
| Morphine | Deep purplish red |
| Opium | Dark grayish reddish brown |
| Oxycodone | Pale violet |
| Propoxyphene | Blackish purple |
| Sugar | Dark brown |
Mechanism
The colour change from morphine is proposed to be a result of two molecules of morphine and two molecules of formaldehyde condensing to the dimeric product which is protonated to the oxocarbenium salt.[15]
See also
References
- "Color Test Reagents/Kits for Preliminary Identification of Drugs of Abuse" (PDF). Law Enforcement and Corrections Standards and Testing Program. July 2000. Retrieved 24 July 2011.
- Toxicology. Volume 2 : mechanisms and analytical methods — New York, New York ; San Francisco, California : Academic Press, 1961 — p. 247.
- Каталог диссертаций Дерптского Университета с 1811 по 1914 гг. Archived 4 March 2016 at the Wayback Machine // Ин-т экспериментальной медицины
- Marquis, Eduard. Über den Verbleib des Morphin im tierischen Organismus. Magister Dissertation 1896, Jurjew, Arb. Der Pharm. Inst. zu Dorpat 15, 117 (1896);
Pharmazeutische Zentralhalle für Deutschland., 814 (1896);
Pharmazeutische Zeitschrift für Russland. 38, 549 (1896). - Юрген Торвальд Сто лет криминалистики — М: Прогресс, 1974
- "FAQ". ElevationChemicals. Retrieved 2 December 2018.
- "Reagent Testing Instructions". Retrieved 21 December 2016.
- Morris, Jeremiah. Color Tests and Analytical Difficulties with Emerging Drugs (PDF). Johnson County Sheriff’s Office Criminalistics Laboratory: NIST. p. 36. Retrieved 10 May 2014.
- "EcstasyData 5-MeO-MiPT". EcstasyData.
- "Controlled Substances Procedures Manual" (PDF). Virginia Department of Forensic Science. 2013. Archived from the original (PDF) on 13 August 2013. Retrieved 6 August 2013.
- "Color Test Reagents/Kits for Preliminary Identification of Drugs of Abuse" (PDF). Law Enforcement and Corrections Standards and Testing Program. July 2000. Retrieved 24 July 2011.
- O’Neal, C. L.; Crouch, D. J.; Fatah, A. A. (2000). "Validation of twelve chemical spot tests for the detection of drugs of abuse". Forensic Science International. 109 (3): 189–201. doi:10.1016/S0379-0738(99)00235-2. PMID 10725655.
- Johns, S. H.; Wist, A. A.; Najam, A. R. (1 July 1979). "Spot Tests: A Color Chart Reference for Forensic Chemists" (PDF). Journal of Forensic Sciences. 24 (3): 631. doi:10.1520/JFS10882J. S2CID 68755072.
- Morris, Jeremiah (2004). "Analytical Profile of Modafinil" (PDF). Microgram Journal. 3 (1–2): 28. Retrieved 9 October 2013.
- Lancashire, Robert J. (13 October 2011). "Unit 9: Crime - Reagent Kits". University of the West Indies, Mona Campus. Retrieved 17 March 2014.