Octadecylsilane chemically bonded silica is widely used in chromatography as a stationary phase, particularly in reversed-phase high-performance liquid chromatography (HPLC). Its hydrophobic surface makes it ideal for separating non-polar and moderately polar compounds, such as pharmaceuticals, environmental pollutants, and natural products. The material is also employed in solid-phase extraction (SPE) for sample preparation, where it effectively isolates and concentrates analytes from complex matrices. Additionally, it finds applications in the purification of biomolecules, such as peptides and proteins, due to its ability to selectively bind hydrophobic molecules. Its stability and reproducibility make it a preferred choice in analytical laboratories for achieving precise and reliable results.