Amphetamine Test for Caffeine: A Simple Qualitative Detection Method

Amphetamine Test for Caffeine Introduction

Given the increasing instances where amphetamine is either completely replaced by caffeine or mixed with it, we are sharing a straightforward Amphetamine Test for Caffeine. This qualitative procedure allows for visual identification of caffeine presence in a sample.

Materials Required:

1. Concentrated Nitric Acid (~68%) – available at most chemical reagent suppliers.
2. Ammonia Solution (25%) – note that 10% solutions are insufficient; 25% can be easily purchased from online chemical supply retailers.

Step-by-Step Instructions for Amphetamine Testing:

1. Prepare the Sample
   Place the substance into a heat-resistant container made of transparent or white glass. It’s important that the material allows you to clearly observe any color changes or reactions.
2. Apply Nitric Acid
   Add a few drops of concentrated nitric acid to the sample.
3. Evaporate to Dryness
   Gently heat the mixture until it has completely evaporated.
4. Add Ammonia Solution
   Once dry, add the 25% ammonia solution to the residue.
5. Evaporate Again
   Heat the sample again until all liquid has evaporated.

Amphetamine Test Interpreting the Results:

Compare the final appearance of the sample with the visual references provided:

• 1. Complete Substitution (Amphetamine Replaced by Caffeine)
  The result will match images 1.

• 2. Mixture of Caffeine and Amphetamine (Approx. 30% Caffeine, 70% Amphetamine)
  The result will correspond to image 2.

• 3. Pure Amphetamine Sample
  The final result should resemble image 3.

Amphetamine Test Final Observations:

• The brighter the yellow coloration, the higher the concentration of amphetamine.
• When ammonia is added to amphetamine, a distinct oil-like residue can form.
• In contrast, caffeine reacts with ammonia to produce a red-brown residue upon drying.

This Amphetamine Test for Caffeine offers a quick and effective visual method to assess whether a sample contains caffeine, amphetamine, or a mixture of both.

Conclusion

The Amphetamine Test for Caffeine is a practical, low-cost method for quickly identifying whether a substance contains caffeine, amphetamine, or a combination of both. By relying on clear visual indicators—such as color changes and residue characteristics—it enables fast, on-the-spot analysis without the need for advanced laboratory equipment. This makes it a valuable tool for both safety verification and preliminary substance screening, helping to prevent misuse and ensure product authenticity.

Sources

1. KOZUKA, HIROSHI, M. A. T. A. J. I. R. O. KoYAMA, and TOMOAKI OKITSU. “Murexide reaction of caffeine using nitric acid.” Chemical and Pharmaceutical Bulletin 30.3 (1982): 941-945. https://www.jstage.jst.go.jp/article/cpb1958/30/3/30_3_941/_article/-char/ja/
2. Bruce, C., D. H. Yates, and P. S. Thomas. “Caffeine decreases exhaled nitric oxide.” Thorax 57.4 (2002): 361-363. https://pmc.ncbi.nlm.nih.gov/articles/PMC1746303/pdf/v057p00361.pdf
3. Sánchez-Viesca, Francisco, and Reina Gómez. “A novel transamination reaction in a murexide-like sequence for caffeine detection.” Earthline Journal of Chemical Sciences 11.3 (2024): 437-444. https://www.earthlinepublishers.com/index.php/ejcs/article/view/900