Definition - What does Stationary Phase mean?
The stationary phase is one of two phases that exist in a chromatographic system. The other phase is called the mobile phase. The stationary phase is a solid, a liquid, or a gel that remains static when a gas or liquid moves over its surface and separates out into its various components.
WorkplaceTesting explains Stationary Phase
Chromatography is used to perform confirmatory urine drug testing which detects if a particular drug is present in a sample. In chromatography, substances in the mobile phase pass through the stationary phase and become separated when adsorbed onto the surface of the stationary phase. There is a dynamic balance between the stationary and mobile phases that enable this separation. The level of separation is dependent on the measure of attraction between the stationary phase and the substance.
The stationary phase can be articulated according to its state, such as a solid stationary phase or a liquid stationary phase. In gas chromatography, the stationary phase typically consists of tightly packed beads, whereas in liquid chromatography, it can consist of paper, beads, or other material. High-performance liquid chromatography or gas chromatography/mass spectrometry are typically used in confirmatory urine drug testing.