Page 75 - Phytochemistry 2 (06-PG 605)

Identification of cocaine
Cocaine causes numbness of tongue and lips. Cocaine is

negative Vitali-Morine’s. Most of the tests for identification of
cocaine depends on the crystallographic characters of cocaine
derivatives.
1- When few mg of cocaine HCl are dissolved in few drops of

water and treated with 1 ml of N/10 potassium permanganate, a
violet crystalline precipitate is formed which shows
characteristic crystalline aggregates under the microscope.
This test is used also for differentiation of cocaine from
cinnamyl cocaine.
2- When cocaine HCl is mixed with a drop of platinic chloride
solution, yellow needles are obtained.
3- With aurichloride solution, crystals of stellate rods are
obtained (very sensitive 1:20 000).
4- When cocaine is heated with 0.1 ml sulphuric acid for 5 min,
cooled cautiously then 2 ml water added; an aromatic odour
of methyl benzoate is obtained. When the solution is cooled
and allowed to stand for few hours, crystals of benzoic acid
is obtained.
Estimation of cocaine

Cocaine being strong base can be determined volumetrically
by the usual methods and by non-aqueous titration for cocaine and
cocaine HCl.
Uses

Local anaesthetic in small operations. Synthetic local
anaesthetics are now preferable than cocaine.

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