Specificity of the chemical test-Ghamrawy and Duquenois-was evaluated with respect to eleven different local plant species. Some plants responded to colour spot tests similar to the response given by Cannabis sativa L. Thin Layer and Gas chromatographic methods were found to be specific for the identification of cannabinoids in Cannabis sativa L. extracts. A local Cannabis resin and that from United Nations Laboratory were examined qualitatively with the U.V and I.R. Spectrophotometry. The I.R. spectra of the resins were used to evaluate the maturity of the samples.
Seized samples of Cannabis sativa L. (Indian Hemp) sent for analysis by law enforcing bodies in Ghana comprised mainly of the flowering tops of the plant, and sometimes, the whole uprooted plant. These samples are seized under various conditions. The Police may uncover a Cannabis farm which may be concealed amongst other crops like cassava, tomatoes and pepper. If the undergrowth of a farm is overgrown, other plant species might make it difficult for the law enforcing officer to recognize the Cannabis. The illegal dealer in Cannabis may adulterate wrappers of Cannabis with some other plant materials. Cases have been known of suspected Cannabis smokers chewing up partly smoked Cannabis wrappers, when apprehended by the Police. Bits and pieces of the chewed up plant materials may be sent to a laboratory for analysis by the Police.
It is apparent that analytical methods used for the identification of seized Cannabis sativa L. should be selective and specific. It has been reported that some plant materials other than Cannabis sativa L. respond positively to some of the chemical tests for the Cannabis sativa L. notably Beams, Ghamwary and Duquenois tests (1,2,3).
© The Author(s) 1974. Published by the Pharmaceutical Society of Ghana (PSGH). This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.