Simple and accurate candidate reference measurement procedure for total testosterone in human serum by one-step liquid-liquid extraction coupled with isotope dilution mass spectrometry

• Published in: Analytical and bioanalytical chemistry Vol. 411; no. 28; pp. 7519 - 7528
• Main Authors: Chen, Yizhao, Teo, Hui Ling, Liu, Hong, Loh, Tze Ping, Liu, Qinde, Teo, Tang Lin, Lee, Tong Kooi, Sethi, Sunil Kumar
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-11-2019; Springer; Springer Nature B.V
• Subjects: Analytical Chemistry; Biochemistry; Calibration; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Chromatography; Chromatography, Liquid - methods; Dilution; Food Science; Humans; Immunoassay; Indicator Dilution Techniques; International System of Units; Ions; Isotopes; Laboratory Medicine; Liquid chromatography; Liquid-liquid extraction; Liquid-Liquid Extraction - methods; Mass spectrometry; Mass spectroscopy; Measurement; Medical laboratories; Monitoring/Environmental Analysis; Quality assessment; Quality control; Reference Standards; Reproducibility of Results; Research Paper; Scientific imaging; Spectroscopy; Tandem Mass Spectrometry - methods; Testosterone; Testosterone - blood; Testosterone - standards; Uncertainty; United Kingdom; Singapore; Isotope dilution mass spectrometry; Liquid-liquid extraction; Testosterone; Human serum; Liquid chromatography-tandem mass spectrometry; Reference measurement procedure
• DOI: 10.1007/s00216-019-02152-y
• EISSN: 1618-2650
• ISSN: 1618-2642

Testosterone in human serum is commonly tested in clinical laboratories using immunoassay methods as well as liquid chromatography-tandem mass spectrometry (LC-MS/MS) methods. To standardize and ensure the accuracy of the measurement results, reference procedures with higher metrological order are required. A simple measurement procedure based on one-step liquid-liquid extraction (LLE) and liquid chromatography-isotope dilution tandem mass spectrometry (LC-IDMS/MS) was developed for total testosterone in human serum. The procedure involved serum spiked with
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C
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-testosterone, equilibration for 2 h, and extraction with an organic solvent. Testosterone certified reference material (CRM) was used as the calibration standard to ensure the traceability to the International System of Units (SI). Testosterone in serum CRMs from the National Institute for Standards and Technology (NIST) and LGC were used to validate the accuracy of the newly developed method. The deviations of the obtained values from the NIST and LGC certified values ranged from −0.55% to 0.45%. Similarly, the coefficient of variations (CVs) of the replicate measurements were in the range of 0.55% and 0.78%, respectively. The relative expanded uncertainties were comparable with those of the certified materials. The newly developed LC-IDMS/MS procedure demonstrated adequate trueness and precision, and was simple to perform. The method can be used for value assignment of testosterone in external quality assessment (EQA) materials as well as certification of CRMs in the future.
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