Solid phase extraction

Solid phase extraction (SPE) is a sample preparation process by which compounds that are dissolved or suspended in a liquid mixture are separated from other compounds in the mixture according to their physical and chemical properties.

Overview

Solid phase extraction is used in the laboratory to either isolate a specific compound of interest from a complex mixture or to clean up a sample before analysis. The process is widely used in a variety of areas such as environmental science, forensics, and biochemistry.

Process

The SPE process involves four steps: conditioning, loading, washing, and elution.

• Conditioning: The SPE cartridge is conditioned by passing a solvent through it to wet the stationary phase and activate the functional groups.
• Loading: The sample is passed through the cartridge. The analytes of interest are retained on the stationary phase while other components are washed away.
• Washing: A solvent is passed through the cartridge to remove any remaining impurities.
• Elution: A solvent that can disrupt the interaction between the stationary phase and the analytes is passed through the cartridge, eluting the analytes of interest.

Applications

Solid phase extraction has a wide range of applications in various fields. In environmental science, it is used to extract pollutants from water and soil samples. In forensics, it is used to isolate drugs and other substances from biological samples. In biochemistry, it is used to purify proteins and other biomolecules.

See also

• Liquid-liquid extraction
• Chromatography
• Sample preparation