title: Determination of serum thyroxine enantiomers in patients by liquid chromatography with a chiral mobile phase.
abstract: A chromatographic method for the separation and determination of D- and L-thyroxine enantiomers (D-, and L-T4) in human serum with a chiral ligand ion-exchange system using a chiral mobile phase additive and a silica column was established. An aqueous eluent containing L-proline (L-pro) sufficiently complexed copper II ions and triethylamine (TEA) was used. It was monitored with a UV detector. The separation was completed in 12 min. The method has acceptable sensitivity, precision and accuracy for analysis. The limit of detection and the limit of quantitation for both D- and L-T4 were 0.1 microg/ml and 0.8 microg/ml, respectively. Calibration curves were linear within 1-100 microg/ml; the mean correlation coefficients were r(D-T4)=0.9986 for D-T4 and r(L-T4)=0.9978 for L-T4. T4 enantiomers were separated on baseline under the optimum condition. L-T4 eluted before D-T4. The concentration of D-T4 and L-T4 in 45 thyroid patients serum (hyperthyroid, hypothyroid, thyroidectomy, goitre or thyroiditis) using HPLC was determined, those results showed that D,L-T4 concentration varied in different thyroid patient. Attention should be paid to this result in treating thyroid disease in the clinic.
authors.affiliation: Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, Gansu, China. wangrr@public.lz.gs.cn
authors.forename: Rong
authors.initials: R
authors.lastname: Wang
authors.forename: Zheng-Ping
authors.initials: ZP
authors.lastname: Jia
authors.forename: Xiao-Li
authors.initials: XL
authors.lastname: Hu
authors.forename: Li-Ting
authors.initials: LT
authors.lastname: Xu
authors.forename: Yong-Min
authors.initials: YM
authors.lastname: Li
authors.forename: Li-Ren
authors.initials: LR
authors.lastname: Chen
mesh_terms: D002138:Calibration; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D011786:Quality Control; D011863:Radioimmunoassay; D015203:Reproducibility of Results; D013056:Spectrophotometry, Ultraviolet; D013237:Stereoisomerism; D013959:Thyroid Diseases / Q000097:blood; D013974:Thyroxine / Q000097:blood*
chemical_list: D013974:Thyroxine