Short-term stability of testosterone and epitestosterone conjugates in urine samples: quantification by liquid chromatography-linear ion trap mass spectrometry.
A simple method using liquid chromatography-linear ion trap mass spectrometry for simultaneous determination of testosterone glucuronide (TG), testosterone sulfate (TS), epitestosterone glucuronide (EG) and epitestosterone sulfate (ES) in urine samples was developed. For validation purposes, a urine containing no detectable amount of TG, TS and EG was selected and fortified with steroid conjugate standards. Quantification was performed using deuterated testosterone conjugates to correct for ion suppression/enhancement during ESI. Assay validation was performed in terms of lower limit of detection (1-3ng/mL), recovery (89-101%), intraday precision (2.0-6.8%), interday precision (3.4-9.6%) and accuracy (101-103%). Application of the method to short-term stability testing of urine samples at temperature ranging from 4 to 37 degrees C during a time-storage of a week lead to the conclusion that addition of sodium azide (10mg/mL) is required for preservation of the analytes.
Saudan
Christophe
C
Laboratoire Suisse d'Analyse du Dopage, Institut Universitaire de Médecine Légale, Chemin des Croisettes 22, 1066 Epalinges, Switzerland. christophe.saudan@chuv.ch
Entenza
José M
JM
Baume
Norbert
N
Mangin
Patrice
P
Saugy
Martial
M
D002138:Calibration; D002675:Child, Preschool; D004845:Epitestosterone / Q000652:urine*; D005260:Female; D006801:Humans; D013058:Mass Spectrometry / Q000379:methods*; D012680:Sensitivity and Specificity; D013739:Testosterone / Q000652:urine*
D013739:Testosterone; D004845:Epitestosterone