Phytochemicals are compounds found in plants that are known for their anti-inflammatory, antioxidant, and anticancer properties, making them important for human health. While these chemicals can be synthesized, research has shown that patients tolerate natural extracts, such as those from willow bark, better. However, purifying these substances from plant matrices is complicated due to their low concentration, expensive scale-up process and complexity of the plant matrix. In this thesis, the aim was to explore the behavior of phytochemicals on Sephadex- G gel. Previous studies have shown unexpected behavior of this gel, and understanding this behavior could enhance phytochemical separation. Model compounds were used with varying chemical properties and worked with column and batch adsorption. Based on the results presented in this thesis, it can be concluded that the Sephadex G-25 matrix has different affinities toward different organic compounds. The retention time of phenol was observed to be the longest, followed by toluene and benzene, indicating that phenol has the strongest interaction with the Sephadex G-25 matrix. However, further research is needed to determine the exact nature of the interaction between phenol and the Sephadex G-25 matrix, as the data obtained in this study is not sufficient to conclude that hydrogen bonding is the only factor contributing to this interaction. More research is needed to further understand the source of the interaction between Sephadex gel and phenolic compounds.