title: Electron capture negative chemical ionization mass spectrometry of chemically oxidized corticosteroids.
abstract: A procedure which can be used to increase the electron affinity of corticosteroids for purposes of quantitative analysis is proposed. Ten important corticosteroids are chemically oxidized to 1,4-androstadien-3,11,17-trione or 4-androsten-3,6,17-trione structural steroid analogs to enhance their electrophilicity prior to detection by electron capture negative chemical ionization mass spectrometry. The choice of oxidation reagent, a preliminary assessment of the structure-response relationship of the oxidation products, the optimization of negative ion formation as a function of source temperature and the basis for distinguishing the isomers dexamethasone and betamethasone are addressed.
mesh_terms: D000305:Adrenal Cortex Hormones / Q000032:analysis*; D001623:Betamethasone / Q000032:analysis; D055598:Chemical Phenomena; D002621:Chemistry; D002849:Chromatography, Gas; D003907:Dexamethasone / Q000032:analysis; D013058:Mass Spectrometry; D010084:Oxidation-Reduction; D013696:Temperature
chemical_list: D000305:Adrenal Cortex Hormones; D003907:Dexamethasone; D001623:Betamethasone