Illicitly imported Cannabis products: some physical and chemical features indicative of their origin

Samples taken from seizures of illicitly imported cannabis and cannabis resin of known geographical origin have been examined by thin-layer chromatography. The chromatographic characteristics were considered in conjunction with the gross physical appearance of the materials and it was found possible to discriminate between samples of different origin. Thus by carrying out thin-layer chromatography and a visual inspection on a sample of unknown provenance, an opinion as to its geographical origin can be offered. Extensive use is made of a reference collection of samples.