The purpose of the study is to develop methods for identifying terpenoids and assessing the quantitative content of essential oil in the shoots of western thuja (Thuja occidentalis). The object of the study was samples of thuja occidentalis shoots. The raw materials were used fresh. To carry out qualitative reactions, well-known methods were selected that are most often used in the analysis of essential oil raw materials. Identification of essential oil components was carried out by TLC on Silufol plates. A solution of α-pinene was used as a standard. The quantitative content of essential oil in the raw materials was determined by steam distillation in accordance with the GPM method 1.5.3.00010.15 Determination of the content of essential oil in medicinal plant raw materials and medicinal herbal preparations. The authors proposed qualitative reactions for identifying terpenoids in raw materials, which can be used to form the “Authenticity” section for a new type of raw material - thuja occidentalis shoots. α-pinene was identified by TLC. A quantitative assessment of the essential oil content in raw materials was carried out. Qualitative reactions were experimentally selected to confirm the presence of terpenoids in alcoholic extracts from thuja occidentalis shoots, as well as for unsaturated compounds in essential oil obtained by steam distillation. Using TLC, α-pinene was identified in the analyzed samples. The presence of additional 8 adsorption zones in the essential oil samples was also revealed. Assessment of the quantitative content of essential oil in raw materials, carried out according to method 2 OFS.1.5.3.00010.15 “Determination of the content of essential oil in medicinal plant raw materials and medicinal herbal preparations.” The data obtained during the experiment allows us to recommend the inclusion of an essential oil content of at least 2.84% in the quality indicators of western thuja shoots.
