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Published on: August 30, 2018
The analysis of thyroxine in human serum by an 'exact matching' isotope dilution method with liquid
Chris J Hopley1, Peter Stokes, Kenneth S Webb
1Laboratory of the Government Chemist (LGC Limited), Queens Road, Teddington, Middlesex TW11 0LY, UK.
Abstract:
A method for the analysis of thyroxine in human serum, utilising 'exact matching' isotope dilution mass spectrometry (IDMS) in combination with liquid chromatography/tandem mass spectrometry (LC/MS/MS), has been developed with a limit of quantification of 0.5 ng g(-1) of thyroxine in human serum. The extraction and clean-up of thyroxine from serum involves an efficient protein-precipitation stage followed by a solid-phase extraction procedure to produce an extract essentially free from interfering compounds. The method is reproducible, with expanded uncertainties of less than 2%, and is relatively fast to perform.
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