Clinical Chemistry AACC Online Job Center
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Clinical Chemistry 29: 2106-2110, 1983;
This Article
Right arrow Full Text (PDF)
Right arrow Submit an electronic Letter to
the Editor about this paper
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Moller, B.
Right arrow Articles by Bjorkhem, I.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Moller, B.
Right arrow Articles by Bjorkhem, I.

Clinical Chemistry, Vol 29, 2106-2110, Copyright © 1983 by American Association for Clinical Chemistry

Isotope dilution--mass spectrometry of thyroxin proposed as a reference method

B Moller, O Falk and I Bjorkhem

We describe a highly accurate and specific method based on isotope dilution--mass spectrometry for assay of thyroxin in serum. A fixed amount of 2H2-labeled thyroxin is added to a fixed amount of serum. Thyroxin is isolated from the serum by an extraction--solvent- distribution method, converted into the N,O-bis(trifluoroacetyl)methyl ester, and subjected to combined gas chromatography--mass spectrometry. The amount of thyroxin is determined from recordings at m/e 799 and m/e 801. These two ions correspond to the M-184 peak in the mass spectrum of the derivative of unlabeled and 2H2-labeled thyroxin, respectively. With this derivative and with the specific gas-chromatographic conditions used, the "memory" effects observed in previous work were absent. The accuracy of the method was checked by analyses of serum samples without addition of internal standard and by different recovery experiments. The intra-assay variation (CV) was less than 2%, the interassay variation (CV) less than 3.5%. We suggest that this method may be used as a Reference Method. Results by the present method were compared with those by a commercial radioimmunoassay. To our knowledge this represents the first time that radioimmunoassay of thyroxin has been evaluated with a more nearly accurate method. There was excellent agreement between results by the two methods (r = 0.997). We conclude that radioimmunoassay of serum thyroxin is sufficiently accurate for use in clinical work.


The following articles in journals at HighWire Press have cited this article:


Home page
 Clin. Chem.Home page
B. Yue, A. L. Rockwood, T. Sandrock, S. L. La'ulu, M. M. Kushnir, and A. W. Meikle
Free Thyroid Hormones in Serum by Direct Equilibrium Dialysis and Online Solid-Phase Extraction-Liquid Chromatography/Tandem Mass Spectrometry
Clin. Chem., April 1, 2008; 54(4): 642 - 651.
[Abstract] [Full Text] [PDF]

Home page
 Clin. Chem.Home page
S. S-C. Tai, L. T. Sniegoski, and M. J. Welch
Candidate Reference Method for Total Thyroxine in Human Serum: Use of Isotope-Dilution Liquid Chromatography-Mass Spectrometry with Electrospray Ionization
Clin. Chem., April 1, 2002; 48(4): 637 - 642.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1983 by the American Association for Clinical Chemistry.