Endocrine Abstracts

Introduction: It has been recognised in EQA schemes in Europe and America that the reproducibility between labs using LC–MS for testosterone analysis is not optimal for this technique. We decided to conduct a calibration exercise to investigate the variability seen between labs.Methods: Aqueous and matrix matched serum samples were sent to labs participating in the NEQAS testosterone scheme. The labs were asked to measure these samples blind using t...

Introduction: We have developed a highly sensitive LC–MS assay in an attempt to improve the measurement of salivary testosterone in female samples.Methods: A 200 μl saliva sample, calibrators or QC were mixed with 10 μl working internal standard (0.1 μg/l) and 1 ml of methyl tert-butyl ether (MTBE). Vortex mixed for 4 min and frozen at −80 °C (1 h). Unfrozen organic layer was transferred to a glass tube and evaporated. The ...