Fifty years of development of opium characterization methods.

In view of the recent call by the Sub-Commission on Illicit Drug Traffic and Related Matters in the Near and Middle East, for the "development of mechanisms to identify, with more precision and through laboratory analysis, the sources of opium seized from the illicit traffic" [1], the present paper reviews the rationale and preconditions for any practical and reliable characterization and origin-correlated classification of opium. In that context, the results of the early international efforts under the aegis of the United Nations from 1951 to 1967, as well as the rather sporadic investigations in this direction since 1968, are described. Finally, it is demonstrated that in spite of the application of modern computer-based technology, the main obstacle to comprehensive opium characterization and typology is still the lack of an extensive reference collection of opium samples of known origin.