Chemistry and Crime

Narcotics and Test Reagent Kits.
UN Drug Report Info 2014
Cannabis useage across the world, 2012
An interactive map showing major drug use by region, 2012.
Sources: United Nations Office on Drugs and Crime (UNODC), Annual Reports Questionnaire Data/DELTA and National Government Reports

The World Customs Organisation (WCO) Illicit Trade Reports now cover drugs and tobacco etc. The latest, generally published in June, (2013 report) is available. Initially these analysed seizures on a regional basis and by category of drug intercepted, and focussed in particular on routings, means of transport and concealment methods used. Emphasis was placed on the illegal trade in opiates, cocaine, cannabis, and psychotropic substances. The 2009 figures showed that there were 14,127 seizures of drugs, yielding a total of 533 tonnes of narcotics, including 43 tonnes of cocaine, 408 tonnes of cannabis and 21 tonnes of opiates. The number of seizures in 2009 remained relatively stable compared with 2008, although there was a decrease in the quantities of drugs intercepted (533 cf. 600 tonnes).

Regional Intelligence Liaison Offices (RILO) 2007 2008 2009 2011 2012
Asia and the Pacific 1,353 1,476 1,879 1,320 2,16
Caribbean 51 41 136 25 44
Central Africa 9 2 6 19 10
CIS Region (Commonwealth of Independent States) 429 447 461 1,137 1,256
Eastern and Central Europe 223 250 291 339 471
Eastern and Southern Africa 75 115 62 43 20
Middle East 164 207 273 1,151 989
North Africa 405 389 359 125 86
North America 537 472 na 32,752 29,690
South America 614 753 893 746 541
West Africa 64 102 78 72 129
Western Europe 9,443 10,001 9,689 9,427 7,963
Grand Total 13,367 14,255 14,127 47,156 43,385

Year of ganja seizure in Jamaica 2004 2005 2006 2007 2008
(kg) 20952.14 17654 37198.69 37439.91 35507.4

Globally, the United Nations Office on Drugs and Crime (UNODC) estimated that, in 2009, between 149 and 272 million people, or 3.3% to 6.1% of the population aged 15-64, used illicit substances at least once in the previous year. About half that number were estimated to have been current drug users, that is, having used illicit drugs at least once during the past month prior to the date of assessment. While the total number of illicit drug users has increased since the late 1990s, the prevalence rates have remained largely stable, as has the number of problem drug users*, which is estimated at between 15 and 39 million.

*While there is no established definition of problem drug users, they are usually defined as those who regularly use illicit substances and can be considered dependent, and those who inject drugs.

Cannabis is by far the most widely used illicit drug type, consumed by between 125 and 203 million people worldwide in 2009. This corresponds to an annual prevalence rate of 2.8%-4.5%. In terms of annual prevalence, cannabis is followed by ATS (amphetamine-type stimulants; mainly methamphetamine, amphetamine and ecstasy), opioids (including opium, heroin and prescription opioids) and cocaine. Lack of information regarding use of illicit drugs - particularly ATS - in populous countries such as China and India, as well as in emerging regions of consumption such as Africa, generate uncertainty when estimating the global number of users. This was reflected in the wide ranges of the estimates.

While there are stable or downward trends for heroin and cocaine use in major regions of consumption, this is being offset by increases in the use of synthetic and prescription drugs. Non-medical use of prescription drugs is reportedly a growing health problem in a number of developed and developing countries.

Narcotic Reagent Kits
Identification of narcotics or other controlled substances can be a difficult task. There are many potential methods and formulae, that all require knowledge of chemistry and laboratory techniques. For quick presumptive testing, colour spot tests for identification purposes are typically used, and these are generally completed outside of a laboratory.

The kits are designed so that there is no need for measurement of chemicals or special equipment. In each plastic tube are crushable glass ampoules with the complete chemistry for each test. The specified amount of suspect material is added and the test is then performed according to the instructions. A typical set of reagent test kits are shown below:

narcotic reagent tests
Colour coded results for narcotic tests

No. 1 Mayer's Reagent Alkaloids, Amphetamines
No. 2 Marquis' Reagent Amphetamines, Heroin, MDMA (Ecstasy)
No. 3 Nitric Acid Reagent Heroin, Morphine
No. 4/13 Cobalt-Thiocyanate Reagent Cocaine HCl, Freebase, Crack
No. 5 Dille-Koppanyi Reagent Barbiturates
No. 6 Mandelin Reagent Amphetamines
No. 7 Ehrlich's Reagent Hallucinogens
No. 8 Duquenois-Levine Reagent Marijuana, THC
No. 9 KN (Fast Blue B Salt) Reagent Marijuana, THC
No. 14 Valium Reagent Valium, Flunitrazepam (Rohypnol), Ketamine
No. 15 Methamphetamine,
Simon's and Robadope's Reagent
Methamphetamine, MDMA (Ecstasy)
No. 16 Mecke's Modified Reagent Heroin (White, Black, Brown)
No. 18 Talwin Reagent Talwin
No. 19 Ephedrine Reagent Ephedrine
No. 22 Special Opiates Heroin, Oxycodone
No. 29 PCP Reagent PCP, Methaqualone

Mayer's Reagent
A precipitating reagent for alkaloids prepared from a solution of mercuric chloride and potassium iodide in deionized water.
isoquinoline alkaloid Mayer's Reagent Kit
Isoquinoline alkaloid sub-structure and Mayer's Reagent

Alkaloid + K2[HgI4] ↔ [Alkaloid-H+][HgI3]- ↓ (or [HgI4]) salt
The formation of a creamy-white precipitate is indicative of the presence of one of the narcotic alkaloids or the amphetamines.

This is often the first screening test performed and depending on the result may lead to further testing with Marquis' Reagent or the Dille-Koppanyi Reagent.

Marquis' Reagent
The Marquis reagent is a spot test for alkaloids that was first reported in 1896. The original testing agent was a mixture of 2 drops of 40% formaldehyde and 3 milliliters of concentrated sulfuric acid. It was originally used for detecting small amounts of certain alkaloids, and for distinguishing between them. The signature of the alkaloid is both the initial colour produced, as well as the sequence of colour changes occurring with time. In the early days the Marquis reagent was used primarily to distinguish the opium alkaloids. Each alkaloid had a pattern of colour change.

Marquis' Reagent Kit morphine reaction with Marquis' reagent
Morphine reaction with Marquis' reagent

The colour reaction of morphine with Marquis' Reagent results in a purple to violet colouring. It is proposed that two molecules of morphine and two molecules of formaldehyde condense in the presence of conc. sulfuric acid to the dimeric product which is protonated to the oxoniumcarbenlum salt.

Cobalt Thiocyanate Reagent, Scott's test
Cobalt thiocyanate in aqueous solution and stannous chloride in aqueous solution.
Various field tests are used to identify cocaine/crack in apprehended street samples. Most of them are based on complexation of the alkaloid with cobalt(II) thiocyanate (Co(SCN)2(H2O)4) solution which results in the formation of a blue colour. The cobalt thiocyanate test was developed in 1973 and later improved to make it applicable to crack.
A recent article highlighted the use of TLC for detection of cocaine and suggested the blue colour is a 6 coordinate Co(II) species with one isothiocyanate ligand a bidentate cocaine molecule and 3 waters coordinated?

Scott's Reagent Kit
Scott's Reagent

See as well a study on the variation of acids used for acidifying the solution and the effect of temperature on the test.

A suggested reaction is the change from octahedral pink Co(II) to tetrahedral blue Co(II) similar to that seen for the chloride salts.

[Co(SCN)(H2O)5]+(aq) + 3 SCN-(aq) + 2 R3NH+ ↔ (R3NH)2[Co(SCN)4] + 5 H2O(l)
where [R3NH]+ represents the protonated cocaine ion.

At 4°C the sensitivity of the test was found to double compared to room temperature (22°C), while temperatures in excess of 40°C decreased the sensitivity of the test more than twofold versus room temperature. These findings clearly show the impact that storage, use, and interpretation of commercially available cocaine test kits in typical field settings may experience in very hot ambient temperatures.

Dille-Koppanyi Reagent
The original 2 part test was developed in the 1930s by American pharmacologists Theodore Koppanyi and James M. Dille as a simple spot-test to presumptively identify barbiturates.

Part A is 0.1 g of cobalt(II) acetate dihydrate dissolved in 100 ml of methanol mixed with 0.2 ml of glacial acetic acid. Part B is made up of 5% isopropylamine (v/v) in methanol. Two drops of A are addeded to the substance followed by one drop of B and any colour changes observed.

The test turns phenobarbital, pentobarbital, amobarbital and secobarbital light purple.
Dille_Koppanyi Test Dille_Koppanyi Reagent Kit
Dille-Koppanyi Reagent test

N-non-substituted barbiturates can be detected with Dille-Koppanyi's Reagent. Isopropylamine is responsible for the deprotonation of the barbiturate molecule. The purple colour is caused by complex formation between two barbiturate molecules, two isopropylamine molecules around a tetrahedral cobalt(II). The isopropylamines are thought to act as stabilizers of the complex.

Mandelin Reagent
The Mandelin reagent is used as a simple spot-test to presumptively identify alkaloids as well as other compounds. It is prepared by the addition of 100 mL of concentrated (95-98%) sulfuric acid to 1 g of ammonium vanadate.
structure of yohimbine Mandelin Reagent Kit
The alkaloid Yohimbine and Mandelin Reagent

According to the Journal of the American Pharmaceutical Association Volume 19, Issue 12, pages 1292-1299, December 1930

"An ammonium vanadate-sulfuric acid solution, as a test for strychnine was first proposed by Mandelin in 1883. A few alkaloids besides strychnine will give colour reactions with this reagent. According to Witthaus the following alkaloids give strychnine-like reactions with this reagent:
1. Curarin gives about the same play of colours, but the appearance is very much delayed. Curarin, however, is not extracted with organic solvents in alkaline solutions.
2. Gelsemin produces a purple or red-violet colour.

In 1915, it was shown that yohimbine, an alkaloid obtained from the bark of Corynanthe Johimbe, gives the same purple with Mandelin's reagent as strychnine. However upon dilution with water the purple colour developed by strychnine changes to a beautiful rose-pink colouration, whereas with yohimbine no such colour develops upon dilution.

In 1889, a number of alkaloids were tested with Mandelin's reagent. Distinctive colours with twenty-three of the common alkaloids were obtained. Apart from strychnine, violet or violet-blue colours were obtained with apomorphine and papaverin."

Ehrlich's Reagent
A solution of p-dimethylamino benzaldehyde and concentrated hydrochloric acid.
Ehrlich's Test for LSD Ehrlich's Reagent Kit
Ehrlich's Reagent and reactions with indole type derivatives like LSD

The colouring matter produced is determined by the concentration of the acid, the solvents and other conditions of the reaction. After the condensation of one molecule of LSD with one molecule of p-dimethylamino benzaldehyde, the carbinole is formed. After protonation water is eliminated to form the carbenium ion, which then reacts by the addition of a second molecule of LSD. This is finally oxidized to the blue-coloured cyanine.

Duquenois-Levine Reagent
The test was initially developed in the 1930s by Pierre Duquenois, and was adopted in the 1950s by the United Nations as the preferred test for cannabis, and originally claimed to be specific to cannabis.

The reagent can be prepared by adding 2 grams of vanillin and 2.5 milliliters of acetaldehyde to 100 milliliters of ethanol.
Duquenois-Levine Test Duquenois-Levine Reagent Kit
Duquenois-Levine Reagent

The Duguenois-Levine Test describes the determination of cannabis resin by forming the violet-coloured product above, which can be extracted with chloroform.
It is now recognised that it is NOT specific however, despite this, it may be the only test performed on substances and be used as evidence for conviction.

KN (Fast Blue B Salt) Reagent
KN= Kanto-Shin'etsu Narcotics Control Office, Japan
Presumptive test designed to identify the presence of THC in Marijuana, Hashish or Hash Oil. It is also designed to react with the green leaf material of fresh Marijuana. Upon breakage of the 2nd ampoule, a layering will occur and the lower layer must be a Tomato Red colour for a positive test.

The Reagent contains a solution of naphthanil diazo blue B in chloroform and a solution of aqueous sodium hydroxide.
Fast Blue B with THC KN Fast Blue B Reagent for THC
Possible product of Cannabis detection with Fast Blue B

Valium Reagent - Zimmerman Test
A solution of potassium hydroxide in methanol and a solution of m-dinitrobenzene in isopropanol.

Valium and flunitrazepam

Diazepam, more commonly known by its trade name, Valium, is a benzodiazepine and a controlled substance (Schedule IV in the United States and under International Control as well). It is a potent sedative - hypnotic (CNS depressant), and is one of the most prescribed drugs in the world. It is one of the top five most abused benzodiazepines, and misuse can lead to both psychological dependence and/or physical addiction.

The State of California offers diazepam to condemned inmates as a pre-execution sedative as part of their Lethal Injection program.

Drug-facilitated sexual assault - Date-rape drugs
Flunitrazepam Rohypnol, Rufinol or Roofies are known to induce anterograde amnesia in sufficient doses; individuals are unable to remember certain events that they experienced while under the influence of the drug. This effect is particularly dangerous when flunitrazepam is used to aid in the commission of sexual assault; victims may be unable to clearly recall the assault, the assailant, or the events surrounding the assault.

Rohypnol is manufactured by Hoffman-La Roche. It is sold in tablet form in clear bubble packaging, with the tablets inscribed on one side with the word "Roche." It has no taste or smell. Originally the tablets were manufactured only in white and, if dissolved in liquid, did not affect its colour. But once it became known that Rohypnol was being used to facilitate rape, Hoffman-La Roche began manufacturing an additional version coated in a hard green shell to inhibit dissolution, and containing a strong blue dye.

It is difficult to estimate just how many flunitrazepam-facilitated rapes have occurred.

Zimmerman's test for Benzodiazepines
Zimmerman's test for Benzodiazepines

Methamphetamine, Simon's and Robadope's Reagent
Simon's reagent is composed of an aqueous mixture of sodium nitroprusside, sodium carbonate and acetaldehyde, which is dripped onto the substance being tested. The amine and acetaldehyde produce the enamine, which subsequently reacts with sodium nitroprusside to the imine. Finally, the immonium salt is hydrolysed to the bright cobalt-blue Simon-Awe complex.
Robadope reagent can be used for detecting primary amines.
Acetaldehyde can be replaced with acetone, in which case the reagent detects primary amines instead, giving a purple coloured product.

Note the paper for identification of methamphetamines using FTIR that was recently published in PLoS ONE:
Hughes J, Ayoko G, Collett S, Golding G (2013) Rapid Quantification of Methamphetamine: Using Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR) and Chemometrics. PLoS ONE 8(7): e69609. doi:10.1371/journal.pone.0069609

Mecke's Modified Reagent
The Mecke reagent is used as a simple spot-test to presumptively identify alkaloids as well as other compounds. The reagent which is prepared by the addition of 100 mL of concentrated sulfuric acid to 1 g of selenious acid is dripped onto the substance being tested.

morphine reaction with Mecke's reagent Mecke's Reagent Kit
Mecke's Reagent reaction with morphine

The blue to green colour produced by Mecke's Reagent with morphine is thought to arise from the initial rearrangement to apomorphine, which in the presence of selenious acid is oxidized to the o-quinone of apomorphine.

Frohdes Talwin Reagent
Frohdes Reagent - Presumptive test designed to identify the presence of Pentazocine which is a synthetically prepared prototypical mixed narcotic (opioid analgesic) drug of the benzomorphan class of opioids used to treat moderate to moderately severe pain. It may exist as one of two enantiomers, (+)-pentazocine and (-)-pentazocine. (-)-pentazocine is a κ opioid receptor agonist, while (+)-pentazocine is not.

After the discovery of its misuse, naloxone was added to oral preparations containing pentazocine to prevent the opioid reaction.

Upon breakage of the 2nd ampoule and after shaking, a bright blue appears in the presence of Pentazocine.
The Reagent is prepared from 1 g of sodium molybdate in 100 mL of concentrated H2SO4.

Ephedrine Reagent
An aqueous solution of sodium carbonate and sodium nitroferricyanide and a solution of m-dinitrobenzene in isopropanol.

Ephedrine, pseudo-ephedrine and related species Ephedrine Reagent for ephedrine
(1R,2S)(-)-Ephedrine, (1S,2S)(+)-(pseudo-ephedrine and related species and an Ephedrine Reagent Kit
Chen-Kao Test
Detection of ephedrine by its reaction with copper sulfate and sodium hydroxide, was first noted by Nagai (1892): a purple color appears, which is extractible with ether. This test is sensitive to one part of ephedrine in 400, and if the concentration exceeds 1 in 40 a pinkish purple precipitate is formed, and this is completely soluble in ether.
The formation of a violet-coloured chelate complex with copper sulfate in alkaline medium is considered to be characteristic "selective" for phenylalkylamines with vicinal amino- and hydroxyl-groups and has been in use in pharmaceutical analysis for the simple identification of ephedrine, pseudoephedrine, norephedrine and norpseudoephedrine.
The result of the Chen-Kao reaction is a symmetrical chelate complex. The colour, solubility and the stability of this complex appears to be affected by the structural and steric differences of the alkylamine. Tests on a range of ephedrine-type compounds showed that only ephedrine and pseudoephedrine gave the typical violet solution. Other derivatives produced a blue precipitate.

Cu(ephedrine)2 complex, Bull. Chem. Soc., Jpn., (1964), 37, 1363,

Special Opiates
A solution of sulfuric acid and selenious acid.

PCP Reagent
An aqueous solution of cobalt thiocyanate and concentrated phosphoric acid.

UWI students can see OurVLE for copies of some of the reports mentioned above.

Kovar, Karl-Artur and Martina Laudszun. Chemistry and Reaction Mechanisms of Rapid Tests for Drugs of Abuse and Precursors Chemicals, United Nations Scientific and Technical Notes v.89-51669, Germany. February 1989.

National Institute of Justice. Colour Test Reagents/Kits for Preliminary Identification of Drugs of Abuse, NIJ Standard 0604.01, National Law Enforcement and Corrections Technology Center, Rockville, MD. July 2000.

United Nations Office On Drugs and Crime (UNODC), Laboratory and forensic science services

SCIENTIFIC AND TECHNICAL NOTES SCITEC/20 December 2005 Colour Tests for Precursor Chemicals of Amphetamine-Type Substances

United Nations International Drug Control Programme. Rapid Testing Methods of Drugs of Abuse, UN standard ST/ NAR/13/RE V.1, United Nations, New York, NY. 1994.

Continue to GC-IRMS or return to CHEM2402 course outline.

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