High-Performance Liquid Chromatography (HPLC) is an advanced analytical technique widely used in environmental chemistry for the separation, identification, and quantification of chemical components in complex mixtures. The principle of HPLC is based on the differential partitioning of compounds between a mobile phase and a stationary phase. The mobile phase is a liquid solvent or a mixture of solvents that flows through a column packed with a solid stationary phase under high pressure. Compounds in the sample interact differently with the stationary phase based on their chemical properties, such as polarity, hydrophobicity, or molecular size, causing them to elute from the column at different times. The time taken by a compound to pass through the column, known as its retention time, is characteristic and can be used for qualitative identification. Quantitative analysis is achieved by measuring the detector response, which is proportional to the concentration of the analyte in the sample. The instrumentation of HPLC consists of several key components. The first essential part is the solvent reservoir, which holds the mobile phase. Solvents are typically degassed to remove dissolved gases that can form bubbles, affecting the detector response and flow consistency. The mobile phase is pumped through the system using a high-pressure pump, which ensures a constant and controlled flow rate. The sample introduction system allows precise injection of the analyte into the mobile phase stream, often using an autosampler for reproducibility and efficiency in repeated analyses. The heart of the system is the chromatographic column, packed with stationary phase particles, which may be silica-based, polymer-based, or chemically modified to suit specific separations. Columns can be of various lengths and internal diameters, and particle size