One of the most suitable presumptive tests for synthetic cathinones is the Zimmermann test, which provides a clear and unambiguous response for both the hydrochloride and hydrobromide salts in most cases.
The Zimmermann colour test can also be used to differentiate between the halomethcathinones (such as 4-BMC and 4-CMC) and ketamine. While the halomethcathinones give the same colour test response as ketamine for colour tests such as Marquis, Simon’s and the modified cobalt thiocyanate test, different colour test responses are observed for the Zimmermann colour test.
Zimmermann test reagents.
A small amount of the sample to be tested should be added to a dimple well of a spotting tile and the reagents added sequentially. Negative controls should be used. Any colour change or other noticeable effect occurring immediately on addition of the following reagents should be noted and observations made again after five minutes.
• ● Add 2 drops of 1% w/v 1,3-nitrobenzene in methanol, then
• ● add 2 drops of 15% w/v potassium hydroxide in water.
The results observed with the Zimmermann test for a variety of cathinones are presented in the table.
Typical results obtained for a variety of cathinones and ketamine using the Zimmermann test.
The Zimmermann colour test can also be used to differentiate between the halomethcathinones (such as 4-BMC and 4-CMC) and ketamine. While the halomethcathinones give the same colour test response as ketamine for colour tests such as Marquis, Simon’s and the modified cobalt thiocyanate test, different colour test responses are observed for the Zimmermann colour test.
Zimmermann test reagents.
A small amount of the sample to be tested should be added to a dimple well of a spotting tile and the reagents added sequentially. Negative controls should be used. Any colour change or other noticeable effect occurring immediately on addition of the following reagents should be noted and observations made again after five minutes.
• ● Add 2 drops of 1% w/v 1,3-nitrobenzene in methanol, then
• ● add 2 drops of 15% w/v potassium hydroxide in water.
The results observed with the Zimmermann test for a variety of cathinones are presented in the table.
Typical results obtained for a variety of cathinones and ketamine using the Zimmermann test.
Drug | Immediate colour change | Colour after 5 minutes |
Benzedrone | No colour change | Pale pink |
4-BMC | Yellowish-green | Brown |
Bupropion | No colour change | No colour change |
Butylone | (After ~10 secs.) Very pale pink | Dark purple |
4-CMC | Yellowish-green | Brown |
Ethylone | Light pink | Dark pink |
Eutylone | No colour change | Slight purple |
Flephedrone | Light purple | Dark purple |
Ketamine | Light pink | Purple |
3,4-MDPV | Yellow | Yellow |
Mephedrone | Light purple | Dark red/purple |
Methcathinone | Dark purple | Dark purple |
Methedrone | (After a few secs.) Dark purple | Dark purple |
Methylone | (After ~10 secs.) Light purple | Dark purple |
2-MMC | Dark purple | Dark purple |
3-MMC | Purple | Dark purple |
4-MEC | (After ~10 secs.) Light purple | Purple with dark purple specs |
α-PVP | Light yellow | Light yellow (no change in colour) |
4-TFMMC | Dark purple | Dark purple |
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