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 sulfuric acid.^[1][2] 1g of potassium nitrite is used for every 10 mls of sulphuric acid.^[3] Potassium nitrite may also be substituted by sodium nitrite.^[4][5] It is used to test for cocaine, morphine, 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.

Final colors produced by Liebermann Reagent with various substances

Substance	Color
Alprazolam	No reaction
Cocaine	Yellowish[2]
Morphine	Black[2][6]
Atropine	Red - Orange[7]
Yohimbine	Blue[7]
PMA and PMMA	Purple - Brown[8]
MDMA	Intense Brown[9] - Black[8]
Amphetamine	Intense Olive Green[8]
Methamphetamine	Red[6]
4-FA	Orange[10][11]
Cathinone	Bright Yellow[9]
Methcathinone	Bright Yellow[9]
4-MMC	Bright Yellow[9]
N,N-DMC	Faint Yellow[9]
3-FMC	No reaction[9]
4-MOMC	Faint Orange[9]
Methylone	Orange > Brown[9]
MDPV	Yellow > Green[9]
4-Me-PPP	Orange[12]
Brephedrone	Yellow[12]
4-MEC	Orange[12]
Pentedrone	Yellow[12]
4-Methylbuphedrone	Yellow[12]
Buphedrone	Yellow[12]
Butylone	Yellow > Brown[12] or Green > Brown[9]
3,4-DMMC	Orange[12]
Naphyrone	Brown[12]
Benzedrone	Orange[12]
JWH-307	Dark Yellow[12]
AB-001	Dark Yellow[12]
CB-13	Dark Green[12]
JTE-907	Black (bubbling)[12]
UR-144	Dark Red[12]
URB-597	Yellow Brown[12]
URB602	Dark Brown[12]
URB754	Light Brown[12]
AM-1248	Dark Yellow[12]
AB-034	Red-Orange > Dark Red[12]
A-796,260	Red-Orange > Dark Red[12]
A-834,735	Red-Orange > Dark Red[12]
FUR-144	Dark Red[12]
AKB48	No color change[12]
JWH-073	Yellow - Brown[12]
JWH-018	Yellow - Brown[12]
JWH-200	Dark Yellow - Brown[12]
AM-2201	Yellow - Brown[12]
JWH-203	Yellow - Orange[12]
RCS-4-C4 homolog	Brown[12]
AM-694	Dark Yellow[12]
MAM-2201	Green - Brown[12]
AM-2233	Yellow[12]
STS-135	Brown[12]
4-MeO-PCP	Brown[12]
Methoxetamine	Orange - Brown[12]
Ethketamine	Pale Yellow[12]
3-HO-PCE	Dark Brown[12]
5-MeO-DALT	Dark Brown - Black[12]
4-methyl-aET	Brown[12]
4-AcO-DALT	Black[12]
4-HO-MET	Black[12]
4-HO-MIPT	Black[12]
4-AcO-DET	Black[12]
DPT	Dark brown
aMT	Black[12]
5-IT	Dark Brown[12]
5-APB	Black[12]
6-APB	Dark Purple[12]
Camfetamine	Dark Red[12]
Methiopropamine	Dark Brown[12]
MDAI	Green > Black[12]
5-IAI	Dark Brown[12]
Pethidine	Red - Orange[13]
Mescaline	Black[13]
Allylescaline	Brown - Black[12]
2C-T-2	Red[12] / Purple[14]
2C-P	Green[12]
2C-C	Yellow > Black > Clear
2C-B	Yellow -> Black
b-methoxy-2C-D	Green[12]

See also

• Pill testing
• Liebermann–Burchard test
• Dille–Koppanyi reagent
• Folin's reagent
• Froehde reagent
• Mandelin reagent
• Marquis reagent
• Mecke reagent
• Simon's reagent
• Zwikker reagent

References

1. Horowitz, Benjamin (2009). A Study of the Action of Ammonia on Thymol. Bibliolife. p. 26. ISBN 978-1-110-61089-1. Retrieved 2012-01-25. Since his day the Liebermann reagent (6% potassium nitrite in conc. sulfuric acid) has been extensively used.
2. Bell, Suzanne (30 Jun 2004). Dictionary of Forensic Science (Facts on File Science Dictionary) (Facts on File Science Dictionary Series.). Facts on File Inc. p. 142. ISBN 978-0-8160-5131-1. Retrieved 2012-01-25.
3. Brittain, Harry G.; McLeish, Michael J (20 Mar 1998). Analytical Profiles of Drug Substances and Excipients. 25. Academic Press. p. 106. ISBN 978-0-12-260825-4.
4. (PDF) http://www.austintexas.gov/sites/default/files/files/Police/DC_Technical_Manual_100114.pdf. Liebermann Reagent: Carefully add 5 g sodium nitrite to 50 mL sulfuric acid with cooling and swirling. Missing or empty |title= (help)
5. Drugs and Poisons in Humans: A Handbook of Practical Analysis. Liebermann's reagent: 2 g of sodium nitrate is dissolved in 20 mL of concentrated sulfuric acid.
6. "NARK® II Narcotics Test - NARK20031 - Liebermann Reagent - Meth/Morphine". Retrieved 11 December 2015.
7. DMT Nexus (2011-09-29). "Colorimetric test results for different alkaloids". Retrieved 2012-01-25.
8. EMCDDA (30 Mar 2011). EMCDDA Risk Assessment: Report on the Risk Assessment of PMMA in the Framework of the Joint Action on New Synthetic Drugs. Dictus Publishing. p. 54. ISBN 978-3-8433-2695-7. Retrieved 2012-01-25.
9. Toole KE, Fu S, Shimmon RG, Kraymen N (2012). "Color Tests for the Preliminary Identification of Methcathinone and Analogues of Methcathinone" (PDF). Microgram Journal. 9 (1): 27–32.
10. Uchiyama N, Kawamura M, Kamakura H, Kikura-Hanajiri R, Goda Y (2008). "Analytical Data of Designated Substances Controlled by the Pharmaceutical Affairs Law in Japan, Part II: Color Test and TLC" (PDF). Yakugaku Zasshi. 128 (6): 981–7.
11. "4-FA reaction colour results with liebermann and froehde reagent test kits". Reagent Tests UK. 3 January 2016. Retrieved 29 February 2016.
12. "Color Tests and Analytical Difficulties With Emerging Drugs of Abuse" (PDF). Johnson County Sheriff’s Office Criminalistics Laboratory. 2012. Retrieved 2013-07-16.
13. "Rapid Testing Methods of Drugs of Abuse" (PDF). United Nations International Drug Control Programme. 2012. Retrieved 2013-07-16.
14. "Marquis/Mecke/Mandellin results for stim/empathogen/2C-X, RC's & more - Page 10". www.bluelight.org. Retrieved 2016-08-25.