title: Qualitative confirmation procedure for ephedrines as acetonide derivatives in doping urine samples by gas chromatography/electron ionization mass spectrometry.
abstract: Ephedrines are sympathomimetic amines which have central nervous system stimulating properties and, for this reason, some of them are forbidden in sport by the World Antidoping Agency (WADA). They are screened and quantitated in urine by several published techniques and confirmed by gas chromatography/mass spectrometry (GC/MS). In this paper, a simple and easy confirmation procedure for norpseudoephedrine, norephedrine, ephedrine and pseudoephedrine in human urine by GC/electron ionization (EI)-MS is described. After the addition of diphenylamine as internal standard, a liquid-liquid extraction procedure under alkaline conditions with tert-butyl methyl ether was applied to the samples. The analytes were derivatized with acetone and pyridine to form the correspondent oxazolidine derivatives (acetonide). The EI mass spectra of all the studied substances have many diagnostic ions with relative abundance in accordance with WADA requirements and show great structural information content. The fragmentation of theses derivatives is discussed.
authors.affiliation: Instituto de Medicina del Deporte, Laboratorio Antidoping. Calle 100 y Aldabó, CP 10800, Ciudad de la Habana, Cuba. rodnylad@yahoo.com
authors.forename: Rodny Montes de Oca
authors.initials: RM
authors.lastname: Porto
authors.forename: Arístides Rosado
authors.initials: AR
authors.lastname: Pérez
authors.forename: Margarita Teresa Correa
authors.initials: MT
authors.lastname: Vidal
authors.forename: Mario Granda
authors.initials: MG
authors.lastname: Fraga
mesh_terms: D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006801:Humans; D013287:Illicit Drugs / Q000652:urine*; D010080:Oxazoles / Q000652:urine*; D011427:Propiophenones / Q000652:urine*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D015813:Substance Abuse Detection / Q000379:methods*; D016482:Urinalysis / Q000379:methods*
chemical_list: D013287:Illicit Drugs; D010080:Oxazoles; D011427:Propiophenones; C064210:oxazolidine; C047806:monomethylpropion