title: Differentiation of diiodothyronines using electrospray ionization tandem mass spectrometry.
abstract: Diiodothyronines 3,5-diiodothyronine (3,5-T2), 3',5'-diiodothyronine (3',5'-T2), and 3,3'-diiodothyronine (3,3'-T2) are important metabolites of 3,5,3'-triiodothyronine (T3) and 3,3',5'-triiodothyronine (rT3; reverse T3). In this paper, a novel and rapid method for identifying and quantifying 3,5-T2, 3',5'-T2 and 3,3'-T2 has been introduced using electrospray ionization tandem mass spectrometry (ESI-MS/MS). Fragmentation patterns were proposed on the basis of our data obtained by ESI-MS/MS. MS2 spectra in either negative ionization mode or positive ionization mode can be used to differentiate 3,5-T2, 3',5'-T2 and 3,3'-T2. On the basis of the relative abundance of fragment ions in MS2 spectra under the positive ionization mode, quantification of the 3,5-T2, 3',5'-T2 and 3,3'-T2 isomers in mixtures is also achieved without prior separation.
authors.affiliation: Division of Biology, Ackert Hall, Kansas State University, Manhattan, Kansas 66506-4901, USA. ytz@ksu.edu
authors.forename: Yuntao
authors.initials: Y
authors.lastname: Zhang
authors.forename: Abigail H
authors.initials: AH
authors.lastname: Conrad
authors.forename: Rudy
authors.initials: R
authors.lastname: Thoma
authors.forename: Gary W
authors.initials: GW
authors.lastname: Conrad
mesh_terms: D004104:Diiodothyronines / Q000032:analysis* / Q000097:blood / Q000737:chemistry*; D006801:Humans; D015203:Reproducibility of Results; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D004104:Diiodothyronines