Solid-phase extraction, also referred to as SPE system, is a separation process that bridges the gap between the sample collection and analysis. The solid phase extraction principle is based upon and very similar to chromatographic processes. Often coupled with other analytical techniques and preparation methods to enhance separation, the solid phase extraction procedure involves compounds separated from other compounds according to their physical and chemical properties by dissolving or suspending in a liquid mixture. In addition to automated solid phase extraction, there are different subtypes of extraction that include normal phase SPE, reversed phase SPE, and ion exchange SPE. A solid phase extraction system can be used to isolate compounds of interest from a variety of samples, including urine, blood, water, beverages, soil, and animal tissue.