Solid phase extraction (SPE) is an extraction method that uses a solid phase and a liquid phase to isolate one, or one type, of analyte from a solution. It is usually used to clean up a sample before using a chromatographic or other analytical method to quantify the amount of analyte(s) in the sample. The general procedure is to load a solution onto the SPE phase, wash away undesired components, and then wash off the desired analytes with another solvent into a collection tube. Solid-phase extractions use the same type of stationary phases as are used in liquid chromatography columns. The stationary phase is contained in a glass or plastic column above a frit or glass wool. The column might have a frit on top of the stationary phase and might also have a stopcock to control the flow of solvent through the column. Commercial SPE cartridges have 1-10 mL capacities and are discarded after use.
Separation techniques covers a wide range of instrumentation used to separate samples into their component parts for analysis and measurement. Centrifuges, capillary electrophoresis, laboratory filters, titration, Solid-phase extraction (SPE), and chromatography are major groupings within this family. Chromatography instruments are divided into two main areas, high performance liquid chromatographs (HPLC) and gas chromatographs (GC), and their related columns and detecting devices.