Direct measurement of urinary testosterone and epitestosterone conjugates using high-performance liquid chromatography/tandem mass spectrometry

✍ Scribed by Borts, David J.; Bowers, Larry D.

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 163 KB
• Volume: 35
• Category: Article
• ISSN: 1076-5174
• DOI: 10.1002/(sici)1096-9888(200001)35:1<50::aid-jms912>3.0.co;2-j

✦ Synopsis

Measurement of the ratio of testosterone (T) and epitestosterone (E) in urine has been used as an indication

of 'natural' steroid supplementation for a decade. The direct measurement of the glucuronide and sulfate conjugates of testosterone and epitestosterone by high-performance liquid chromatography/tandem mass spectrometry (HPLC/MS/MS) should resolve a number of issues regarding unusual metabolism due to either genetic disposition or attempts to avoid detection of abuse. Determination of nanomoles per liter (0.1 ppb) concentrations of analytes in a complex biological matrix by HPLC/MS/MS is complicated by sample matrixspecific ion suppression during ESI. Deuterated internal standards of all compounds were used to overcome the effects of suppression. Comparison of the HPLC/MS/MS method with a two-part gas chromatographic/mass spectrometric method showed statistical equivalence in urine samples. Analysis of urine samples with elevated T-glucuronide to E-glucuronide ratios did not show that a significant number could be explained by an elevated excretion of epitestosterone sulfate. The HPLC/MS/MS method was also used further to characterize genetic and metabolic factors that give rise to unusual T/E ratios.