There is a monography of Triethylenetetramine dichlorhydrate (Trientine) in the United States Pharmacopeia. But neither the base nor the salts di- or tetra-chlorhydrate are in the European Pharmacopeia. Triethylène tetramine tetrachlorhydrate, used by AGEPS now as matural, is more soluble then triethylene tetramine dichlorhydrate. It is administred to patients with Wilson's disease, which results from a congenital lack of the copper metabolism. A quantitative purity test of this drug by automated multiple development high-performance thin-layer chromatography is developed and validated. The validation parameters tested are specifically characterized by retention factor, linearity, limits of detection and quantitation of several nanograms, reliability, and accuracy. To determine impurities, the monography of triethylenetetramine dichlorhydrate in the American Pharmacopeia is tested. This method in classic developing tank requires two mobile phases and is not quantitative. Assays in high-performance liquid chromatography with a different column and mobile phase did not give good results for the separation of impurities. Thus, it is not possible to perform comparative validation of the separation of the impurities. Only the assay of triethylenetetramine with potentiometer detection has been validated.