Often called as SPE, Solid Phase Extraction is a Laboratory technique used widely nowadays. The function of the technique is to clean and, or concentrate samples before chromatography.
5 steps can be concluded to describe how SPE works as following. The first step is sample pretreatment, such as pH adjustment, protein precipitation, and filtration. And the second step is Column conditioning, that is to make sure the column is ready for loading sample. After we load the Sample onto the cartridge as the third step, the last two are column wash and sample elution. With interferences being washed from the column, the sample will be eluted by solvent and collected, as while as interference left behind on cartridge.
To optimize the extraction, there are three main parameters that should be known: the choice of column sorbent, wash solvent and eluting solvent. And the choice of solvents depends on what kind of stationary phase you need. When finding the point that balance of three parameters, you will achieve a reliable and sturdy method.