An isotope dilution-liquid chromatography-tandem mass spectrometry-based candidate reference measurement procedure for the quantification of testosterone in human serum and plasma. - Fux E; Schmid R; Singh N; Fleischer S; Bauland F; Köppl D; Gaudl A; Geistanger A; Ceglarek U; Rauh M; Geletneky C; Taibon J (Clinical chemistry and laboratory medicine, 2026)