Steroids Extraction By Reversed-Phase Chromatography
Steroids are a wide class of naturally occurring and synthetic molecules that are essential to a broad range of physiological processes. All possessing cholesterol-based structure, these hormones find their use in a variety of therapies such as inflammation control and blood disorders treatment through control of immune functions. They have also gained in popularity through a less glorious use as the first known doping agents (anabolic steroids). Day-to-day extraction, separation and identification of steroids and metabolites are performed with the assistance of preparative and analytical liquid chromatographic techniques. Steroids and steroid hormones possess moderately polar non-ionic character that allows the use of reversed-phase purification and separation strategies.
Classically, C18 SPE cartridges like SiliaPrep™ Reversed-Phase C18 are used for extraction of steroids providing efficient removal of interfering compounds from urine and plasma samples. While determination of free steroids does not require any extra specific sample treatment, analysis of the total steroids is performed through sample acid or enzymatic hydrolysis.
It has been shown that few endogenous interfering compounds can remain upon reversed-phase extraction. In these specific cases, a second extraction procedure involving Silica cartridges permits efficient final sample clean-up.
Full Text PDF