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J Mass Spectrom. 2000 Jan;35(1):50-61.

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

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1
Athletic Drug Testing and Toxicology Laboratory, Department of Pathology and Laboratory Medicine, Indiana University Medical Center, Medical Science Building A-128, 635 Barnhill Drive, Indianapolis, Indiana 46202-5120, USA.

Abstract

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 matrix-specific 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.

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