Differentiation and comparison of raw, prepared and dross opium.

Comparative studies involving colour tests, thin-layer chromatography (TLC) and gas-liquid chromatography (GLC) were made on raw, prepared and dross opium with a view to establishing means for their differentiation. Analysis of a large number of samples found in south-east Asia showed the typical patterns and results to be quite distinctive in the qualitative and quantitative aspects. The relative proportions of the major alkaloids in the two chromatographic systems were used to advantage in the comparison. Prepared opium was found to have a characteristic yellow fluorescent spot on the TLC plate when viewed under long-wavelength ultraviolet light. No positive marker was found for dross opium, its unusual features being the relatively high morphine and codeine content and the absence of narcotine, meconic acid and especially thebaine. Most of the prepared opium samples were found to have been made from a mixture of raw and dross opium. The modified hallucinogen reagent of Maunder was found to be a suitable alternative chromogenic spray in the TLC analysis.