Solid Phase Extraction (SPE) is a sample preparation technique widely used in analytical chemistry. It involves the separation and concentration of analytes from a sample solution using a solid phase sorbent. The process typically follows several steps: conditioning, sample loading, washing, and elution. During conditioning, the SPE cartridge or sorbent is prepared by wetting it with a solvent compatible with the sample matrix. The sample is then loaded onto the SPE cartridge, where analytes of interest are retained while interfering compounds are washed away. Elution involves the release of analytes from the sorbent using a solvent that is selective for the target compounds. SPE offers advantages such as improved sensitivity, selectivity, and reproducibility compared to traditional liquid-liquid extraction methods. It can be used for a variety of sample matrices including environmental, biological, and pharmaceutical samples. SPE techniques vary based on the sorbent material, cartridge type, and elution solvent used, allowing for customization based on specific analytical needs. Overall, SPE is an essential tool in analytical chemistry for sample cleanup and concentration prior to analysis.