Quality control of medicinal plants with an electronic nose

In the last decades, a new interest in active components of phytodrugs as well as in the control of their quality has pointed out new ways to identify and characterize natural plants which, till present, did not fulfill the claimed specifications—Valerians among them. Valerians exhibit numerous and traditional medical uses. In this paper, the use of an electronic nose to discriminate different varieties of Valerians, was investigated. The principal species—valeriana officinalis (VO) and valeriana wallichii (VW)—with different origins and, in some cases, different years of crop, were clearly separated with the electronic nose. The fact that valeric acid is present in VO variety and not in the VW and that there are differences in the valepotriates concentration in both varieties, determined the importance of discriminating both species, since they are active components exhibiting different therapeutic effect. The electronic nose has demonstrated to be a fast and effective tool to separate both species, giving besides other interesting results. Chemical chromatographic analysis was performed enabling the identification of species separated by the electronic nose.