title: Stable isotope-dilution liquid chromatography/tandem mass spectrometry method for determination of thyroxine in saliva.
abstract: A liquid chromatography/electrospray ionization-tandem mass spectrometry (LC/ESI-MS/MS) method for the determination of thyroxine (T(4)) in human saliva has been developed and validated. The saliva was deproteinized with methanol, purified using a Strata-X™ cartridge, and subjected to LC/ESI-MS/MS. Quantification was based on selected reaction monitoring, and [(13)C(6)]-T(4) was used as the internal standard. This method allowed the reproducible (intra- and inter-assay relative standard deviations, <4.8%) and accurate (analytical recovery, 96.5-99.6%) quantification of the salivary T(4) using a 400 μl sample, and the limit of quantification was 25.0 pg/ml. A preliminary study using the developed method found that there is a diagnosable difference in the salivary T(4) concentration between the euthyroid subjects and the patients with Graves disease.
authors: Laboratory of Analytical and Bioanalytical Chemistry, School of Pharmaceutical Sciences and Global COE Program, University of Shizuoka, Suruga-ku, Shizuoka, Japan. higashi@u-shizuoka-ken.ac.jp
authors: Tatsuya
authors: T
authors: Higashi
authors: Takuya
authors: T
authors: Ichikawa
authors: Chikara
authors: C
authors: Shimizu
authors: So
authors: S
authors: Nagai
authors: Shinsuke
authors: S
authors: Inagaki
authors: Jun Zhe
authors: JZ
authors: Min
authors: Hitoshi
authors: H
authors: Chiba
authors: Shigeo
authors: S
authors: Ikegawa
authors: Toshimasa
authors: T
authors: Toyo'oka
mesh_terms: D000328:Adult; D004355:Drug Stability; D005260:Female; D006111:Graves Disease / Q000378:metabolism; D006801:Humans; D007553:Isotope Labeling / Q000379:methods*; D016014:Linear Models; D008297:Male; D015203:Reproducibility of Results; D012463:Saliva / Q000737:chemistry*; D012680:Sensitivity and Specificity; D053719:Tandem Mass Spectrometry / Q000379:methods*; D013974:Thyroxine / Q000032:analysis* / Q000737:chemistry
chemical_list: D013974:Thyroxine