Marquis Reagent (English Version)

The Marquis reagent is a simple analytical method for identifying certain chemical compounds.

Preparation of the Marquis reagent

The original recipe for the Marquis reagent is the following:

9 parts concentrated sulphuric acid (98%) & 1 part formalin (37% formaldehyde in water)

The advice is to add the sulphuric acid to the formaldehyde, and not the other way around. Heat is generated when these two are mixed, with a risk of splattering. It is also advised to only close the vial/flask when the content is fully cooled to room temperature.

Only use glass vials/flasks to store the Marquis reagent. Vial/flasks with glass stoppers are preferred; not all plastics are sulphuric acid resistant!

Warning

• Sulphuric acid is strong corrosive and toxic acid and can damage eyes and skin severely.
• Formaldehyde is highly toxic and possible carcinogenic. It can be absorbed through the skin. Avoid any direct contact.
• The Marquis reagent needs to be handled and stored with great care. Only glass and porcelain objects are resistant against the reagent.

Alternative recipes

A disadvantage of the original recipe is the fast and intense colour reaction, which could make it difficult to detect any subtle changes. Therefore methanol is often added to the reagent.

90% concentrated sulphuric acid (98%) & 5% formalin (37% formaldehyde in water) & 5% methanol

Use of the Marquis reagent

Put a drop of the Marquis reagent on glass or porcelain surface. Add of little bit of the desired compound and wait for the colour reaction. Compare the result of the colour reaction with the table below.

Table with the colour reactions

Drug	Structure	Colour discription	Particularities	Photo
25B-NBOMe		Olive Green	Colour turns more Green (± 2 min)
25C-NBOMe		Yellow - Orange
25D-NBOMe		No colour change
25I-NBOMe		No colour change
2-AI		Red - Brown	Colour turns more Brown (± 2 min)
2C-B		Green	Colour gets more faint (± 30 min)
2C-C		Light Green - Yellow	Colour gets more faint (± 30 min)
2C-D		Yellow - Light Brown	Colour disappears (± 30 min)
2C-E		Yellow - Light Brown	Colour disappears (± 30 min)
2C-I		Dark Green - Dark Blue	Colour turns more Blue (± 5 min) and gets more faint (± 30 min)
2C-P		Light Brown	Colour disappears (± 30 min)
2C-T-2		Orange - Brown	Fizzes
2C-T-7		Light Orange	Fizzes
2C-T-21		Light Orange	Fizzes
2-FMA		Orange - Brown	Fizzes first, slow colour reaction (± 60 sec)
2-MeO-Ketamine		Light Pink
3C-P		Orange - Red
3-FMC		No colour change	Fizzes
3-MeO-PCP		Ligth Blue - Gray	Slow colour reaction (± 60 sec), Colour turns more Blue (± 5 min)
4-AcO-DiPT		Yellow - Green
4-AcO-DMT		Orange - Green (Brown)	Colour turns more Brown (± 5 min)
4-AcO-MiPT		Orange - Green (Brown)
4-FMC (Flephedrone)		Light Orange - Light Pink	Fizzes
4-FMP / 4-FA (4-Fluoroamfetamine)		Light Pink	Fizzes first, slow colour reaction (± 60 sec)
4-HO-DALT		Yellow - Brown
4-HO-DiPT		Orange - Green (Brown)
4-HO-MiPT		Orange - Green (Brown)
4-MAR		Orange	Slow colour reaction (± 60 sec)
4-MeO-PCP		No colour change
5-APDB (EMA-4)		Brown	Slow colour reaction (± 30 sec)
5-IAI		Orange - Brown
5-MeO-DALT		Light Yellow
5-MeO-DiPT		Light Orange - Green
5-MeO-DMT		Orange - Brown
5-MeO-MiPT		Yellow - Brown
AET		Orange - Brown	Colour turns more Brown (± 5 min)
AH-7921		No colour change	Fizzes
Alprazolam		No colour change
Amphetamine		Dark Orange - Brown
AMT		Orange - Brown	Colour turns more Brown (± 5 min)
APPP		No colour change
Aspirin		Red	Slow colour reaction (± 2 min)
B-DF (Bromo-Dragonfly)		Green - Brown
Buphedrone		No colour change	Fizzes
Butylone		Yellow	Fizzes
BZP		No colour change	Fizzes
Cocaine		No colour change
Cafeine		No colour change
Codeine		Purple - Black
Desoxypipradrol		Orange - Red	Colour turns Darker (± 5 min)
Diazepam		No colour change
DiPT		Yellow - Brown	Colour turns Darker (± 5 min)
DMT		Yellow - Brown
DOC		Yellow - Green
DOI		Light Green
DOM		Light Yellow	Fizzes
DPT		Brown	Colour turns more Brown (± 5 min)
DXM		Black - Grey	Slow colour reaction (± 20 sec)
Escaline		Orange	Colour turns Darker (± 2 min)
Ethaqualone		No colour change
Ethylcathinone		No colour change	Fizzes
Ethylphenidate		No colour change	Fizzes
Fletamine		No colour change
Glucose		Dark Brown	Slow colour reaction (± 1,5 min)
Heroine		Purple - Black
Hydroxyzine		No colour change
JWH-019		Brown	Dissolves poorly
JWH-073		Yellow - Brown
JWH-200		Yellow - Orange	Dissolves poorly
Ketamine		No colour change
Levamisole		No colour change	Fizzes
MDA		Dark Purple - Black	Fizzes
MDAI		Orange - Brown
MDMA		Dark Purple - Black
MDPV		Yellow	Fizzes
Mephedrone		No colour change	Fizzes
Mescaline		Orange
Methaqualone		No colour change
Methoxetamine		No colour change
Methylamphetamine (Meth)		Dark Orange - Brown	Colour turns more Brown (± 5 min)
N-Methylephedrine		Yellow - Light Brown
Methylone		Yellow	Fizzes
Methylhexanamine (Geranamine)/(DMAA)		No colour change	Fizzes
Methylphenidate		Yellow - Orange
Methylmethaqualone		No colour change
Modafinil		Red - Orange (Brown)	Colour turns more Brown (± 2 min)
Morphine		Red - Purple
NaCl (Salt)	Na-Cl	No colour change
Naphyrone		Yellow
O-Desmethyltramadol		Orange - Red
Paracetamol (Acetaminophen)		No colour change
Phenazepam		No colour change
Phendimetrazine		No colour change
Phenmetrazine		No colour change
Phentermine		Orange - Brown	Colour turns more Brown (± 3 min)
PMA		No colour change
Theobromine		No colour change
TMA-2		Light Green
TMA-6		Yellow - Orange	Colour turns Darker (± 3 min)
Tramadol		Orange - Brown
Viagra		No colour change

Other reagents

• Mecke Reagent (English Version)

Links

• Bluelight - Marquis/Mecke/Mandellin results for stim/empathogen/2C-X, RC's & more
• DMT Nexus Forum - Colorimetric test results (Marquis, Mecke, Ehrlich, etc) for different alkaloids
• Reagent Base - Table of (different) reagents
• Colour Test Reagents/Kits for Preliminary Identification of Drugs of Abuse
• Erowid - Ecstasy Testing Kit FAQ