[Chromatographic purity tests of various phenothiazine derivatives. II. Gas chromatography].

Gas chromatographic purity tests of four phenothiazine derivatives chloropromazine, levomepromazine, promethazine and trifluoperazine have been described. Chromatographic system has been optimized that is suitable to the separation of the above substances and their intermediates as well as their side products. Thermostabilities of phenothiazine derivatives were determined, their thermal decompositions were investigated under gas chromatographic circumstances and the data obtained were completed with data of their thermoanalytical tests. Optimal conditions have been worked out and by applying them thermal decomposition of compounds could be minimized. Authors have drawn attention to formation of artificial products which could not be avoided therefore taking into account requirements of purity tests the application of the method is problematical.