Vitali-Morin Test
Definition
Tropane-alkaloid colour test. Fuming HNO3, evaporate, then alcoholic KOH gives violet with atropine and hyoscyamine. Negative on cocaine.
- Detects
- Tropane alkaloids
- Reagents
- Fuming nitric acid, then alcoholic potassium hydroxide
- Positive colour
- Violet
- Positive with
- Atropine, hyoscyamine
- Negative with
- Cocaine
Common questions
Why is a negative cocaine result useful diagnostically?+
Cocaine is also a tropane alkaloid but does not give the violet colour, so a negative Vitali-Morin result on a sample suspected of containing tropane alkaloids helps rule cocaine in or out before more specific chromatographic confirmation.
Is the Vitali-Morin test used as final proof of atropine poisoning?+
No. Like other spot colour tests, it is a rapid presumptive screen. A positive result directs the toxicologist toward confirmatory instrumental analysis such as GC-MS, which identifies the specific alkaloid rather than a colour class.
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