Liebermann reagent

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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] 1 g of potassium nitrite is used for every 10 mL of sulfuric 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[citation needed]
Yohimbine Blue[citation needed]
PMA and PMMA Purple - brown[7]
MDMA Intense brown[8] - black[7]
Amphetamine Orange to red[9]
Methamphetamine Red[6]
4-FA Orange[10][11]
Cathinone Bright yellow[8]
Methcathinone Bright yellow[8]
4-MMC Bright yellow[8]
N,N-DMC Faint yellow[8]
3-FMC No reaction[8]
4-MOMC Faint orange[8]
Methylone Orange > brown[8]
MDPV Yellow > green[8]
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[8]
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]
APINACA 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 (drug) 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]
2C-P Green[12]
2C-C Yellow > black > clear
2C-B Yellow → black
b-methoxy-2C-D Green[12]

See also[edit]


  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. ^ a b c 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. Vol. 25. Academic Press. p. 106. ISBN 978-0-12-260825-4.
  4. ^ "Archived copy" (PDF). Archived from the original (PDF) on 2015-02-01. Retrieved 2015-02-01. Liebermann Reagent: Carefully add 5 g sodium nitrite to 50 mL sulfuric acid with cooling and swirling.{{cite web}}: CS1 maint: archived copy as title (link)
  5. ^ Suzuki, Osamu; Watanabe, Kanako (16 January 2006). Drugs and Poisons in Humans: A Handbook of Practical Analysis. ISBN 9783540275794. Liebermann's reagent: 2 g of sodium nitrate is dissolved in 20 mL of concentrated sulfuric acid.
  6. ^ a b "NARK® II Narcotics Test - NARK20031 - Liebermann Reagent - Meth/Morphine". Retrieved 11 December 2015.
  7. ^ a b 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.
  8. ^ a b c d e f g h i j 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.
  9. ^ "How to test AMPHETAMINE?". 28 September 2020.
  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. doi:10.1248/yakushi.128.981. PMID 18520145.
  11. ^ "4-FA reaction colour results with liebermann and froehde reagent test kits". Reagent Tests UK. 3 January 2016. Retrieved 29 February 2016.
  12. ^ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae af ag ah ai aj ak al am an ao ap aq ar as at au av aw ax ay az ba bb bc bd "Color Tests and Analytical Difficulties With Emerging Drugs of Abuse" (PDF). Johnson County Sheriff’s Office Criminalistics Laboratory. 2012. Retrieved 2013-07-16.
  13. ^ a b "Rapid Testing Methods of Drugs of Abuse" (PDF). United Nations International Drug Control Programme. 2012. Retrieved 2013-07-16.