Ajoint GC/MS analysis of aqueous and aqueous-ethanol solutions of some drugs including menthol, validol, benzocaine, novocaine, and menovazin has been performed using a Varian 3900/2100T (USA) instrument equipped with a Varian Factor Four VF-5ms capillary column. The structures of some impurities that were previously based on theoretical considerations are confirmed. Structural-analytical possibilities of the latest modification of the Varian GC/MS system with an ion-trap source are investigated. It is possible to obtain clear mass spectra even for low-intensity and partly overlapping chromatographic peaks using the given device combination. The results can be used for quality control of drugs based on the investigated compounds. © 2009 Springer Science+Business Media, Inc.