Plants are used for many purposes from past to present. One of them is consumed by people for therapeutic purposes. Some compounds or excessive heavy metal intake during consumption can be harmful to human health. In this study, the amount of Aluminum (Al), Nickel (Ni) and Cobalt (Co), which are toxic elements in the decoction samples obtained with different sample amount (g) and decoction time (min) of Melissa officinalis L. (lemon balm) and Salvia officinalis L. (sage) were investigated. All elements were analyzed by Inductive Coupled Plasma-Mass Spectrophotometer (ICP-MS) at Yozgat Bozok University Science and Technology Application and Research Center. The calibration curve was plotted with 11 points. In both species, the amount of Al was observed to be higher than the other elements. The highest amount of Al was observed in sage plant (1155.6 ppb), while the highest amount of Ni was found in lemon balm (771.3 ppb). In contrast, the maximum amount of Ni and Al was found in the decoction samples of the lemon balm. There was no statistically significant difference between the amounts of Co element in lemon balm and sage decoction samples. In general, increased amount and increased application time of lemon balm plant were found to cause an increase in Al and Ni amounts. As a result, toxicological evaluation of such plants used for their therapeutic properties is important for human and public health. 

Keywords: Sage; Lemon balm; Toxicology; ICP-MS; Decoction.