title: Quantification of 11 thyroid hormones and associated metabolites in blood using isotope-dilution liquid chromatography tandem mass spectrometry.
abstract: This paper describes a novel analytical methodology for the simultaneous determination of absolute and total concentrations of 11 native thyroid hormones and associated metabolites, viz. thyroxine (T4), 3,3', 5-triiodothyronine (T3), 3,3', 5'-triiodothyronine (rT3), 3,5-diiodothyronine (3,5-T2), 3,3'- diiodothyronine (3,3'-T2), 3-iodothyronine (T1), thyronine (T0), 3-iodothyronamine (T1AM), tetraiodothyroacetic acid (Tetrac), triiodothyroacetic acid (Triac), and diiodothyroacetic acid (Diac), in 50-μL of plasma or serum. The method was optimized using four isotopic labeled surrogate and internal standards in combination with solid-phase extraction and LC-MS/MS. The methodology was further evaluated using amphibian plasma and serum with matrix-matched calibration applied for quantification. Method detection limits are 3.5 pg T4, 1.5 pg T3, 2.9 pg rT3, 1.7 pg 3,3'-T2, 2.3 pg 3,5-T2, and between 0.3 and 7.5 pg for the remaining six metabolites in 50 μL aliquots of blood sera or plasma. Accuracies and repeatabilities for all analytes were between 88 and 103 % and 1.31 and 17.2 %, respectively. Finally, we applied the method on adult frog (Xenopus laevis) plasma and tadpole (Rana (Lithobates) catesbeiana) serum. We observed up to seven different thyroid hormones and associated metabolites in tadpole serum. This method will enable researchers to improve the assessment of thyroid homeostasis and endocrine disruption in animals and humans. Graphical Abstract Quantification of 11 thyroid hormones and metabolites from 50 μL plasma or serum using protein denaturation in combination with solid-phase extraction followed by LC-MS/MS.
authors.affiliation: Molecular Toxicology, Energy and Resources Group, Endocrinology, Museum of Vertebrate Zoology, and Department of Integrative Biology, University of California, Berkeley, CA, 94720, USA. martin.hansen@berkeley.edu.|Department of Civil and Environmental Engineering, University of California, Berkeley, CA, 94720, USA. martin.hansen@berkeley.edu.
authors.forename: Martin
authors.initials: M
authors.lastname: Hansen
authors.affiliation: Molecular Toxicology, Energy and Resources Group, Endocrinology, Museum of Vertebrate Zoology, and Department of Integrative Biology, University of California, Berkeley, CA, 94720, USA.
authors.forename: Xuan
authors.initials: X
authors.lastname: Luong
authors.affiliation: Department of Civil and Environmental Engineering, University of California, Berkeley, CA, 94720, USA.
authors.forename: David L
authors.initials: DL
authors.lastname: Sedlak
authors.affiliation: Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, V8P 5C2, Canada.
authors.forename: Caren C
authors.initials: CC
authors.lastname: Helbing
authors.affiliation: Molecular Toxicology, Energy and Resources Group, Endocrinology, Museum of Vertebrate Zoology, and Department of Integrative Biology, University of California, Berkeley, CA, 94720, USA.
authors.forename: Tyrone
authors.initials: T
authors.lastname: Hayes
mesh_terms: D000818:Animals; D001774:Blood Chemical Analysis / Q000379:methods; D002853:Chromatography, Liquid / Q000379:methods*; D045424:Complex Mixtures / Q000097:blood; D011865:Radioisotope Dilution Technique; D011892:Rana catesbeiana; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D053719:Tandem Mass Spectrometry / Q000379:methods*; D013963:Thyroid Hormones / Q000097:blood*; D014982:Xenopus laevis
chemical_list: D045424:Complex Mixtures; D013963:Thyroid Hormones
keywords: Chaotropic agent; Degradation; Extraction; Plasma; Serum; Thyroid hormones