title: Detection of corticosteroids in the presence of organic acids in a liquid chromatography eluent using the negative-ion mode of thermospray mass spectrometry.
abstract: The pKa values of organic acids (HCOOH, CH3CH2COOH, HOCH2COOH, HSCH2COOH and FCH2COOH) in a liquid chromatography (LC) eluent mainly influenced the generation of adduct ions with corticosteroids. The relative abundance of [M + R] adduct ions increased as the pKa value of the organic acid decreased. An interaction between the functional groups of the organic acids in the LC eluent and those of the corticosteroid affected the generation of fragment ions. When HCOOH was present in the mobile phase, the sensitivity to endogenous hydrocortisone and cortisone in human urine was maximized.
authors.affiliation: Doping Control Center, Korea Institute of Science and Technology, Seoul, Korea.
authors.forename: Y
authors.initials: Y
authors.lastname: Kim
authors.forename: T
authors.initials: T
authors.lastname: Kim
authors.forename: W
authors.initials: W
authors.lastname: Lee
mesh_terms: D000305:Adrenal Cortex Hormones / Q000032:analysis* / Q000652:urine; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D002853:Chromatography, Liquid; D006801:Humans; D013058:Mass Spectrometry; D008970:Molecular Weight
chemical_list: D000305:Adrenal Cortex Hormones