title: Derivatisation for the characterisation of neutral oxosteroids by electrospray and matrix-assisted laser desorption/ionisation tandem mass spectrometry: the Girard P derivative.
abstract: The identification, quantification and localisation of steroids in biological fluids and tissues are subjects of considerable importance. Not only do steroids have classical hormonal properties via binding to nuclear receptors, they can also elicit cellular responses via interactions with other proteins. For mass spectrometric analysis, neutral steroids are not readily ionised by either electrospray (ES) or matrix-assisted laser desorption/ionisation (MALDI). In this communication a derivatisation protocol is presented which allows for the rapid analysis of neutral oxosteroids by both ES and MALDI mass spectrometry. Neutral oxosteroids are derivatised to Girard P hydrazones. When analysed by tandem mass spectrometry the derivatised steroids fragment to give structurally informative spectra allowing subsequent steroid identification. The derivatisation method is simple, the reagents are commercially available, and reaction products are easily isolated from the reaction mixture. Analyte identification can be performed at the sub-pg level.
authors.affiliation: Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE-17177 Stockholm, Sweden. william.griffiths@mbb.ki.se
authors.forename: William J
authors.initials: WJ
authors.lastname: Griffiths
authors.forename: Suya
authors.initials: S
authors.lastname: Liu
authors.forename: Gunvor
authors.initials: G
authors.lastname: Alvelius
authors.forename: Jan
authors.initials: J
authors.lastname: Sjövall
mesh_terms: D007202:Indicators and Reagents; D007664:Ketosteroids / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D007202:Indicators and Reagents; D007664:Ketosteroids