Profiling of urinary formestane and confirmation by isotope ratio mass spectrometry

A simple urine pretreatment procedure, leading to extracts free of interferences and permitting a precise and accurate IRMS analysis of formestane was developed, validated and employed in doping control. A combinatorial approach of GC-MS/MS and GC-C-IRMS provides specific detection of endogenous steroid misuse for improved doping analysis. The main aim of this study was to propose a threshold of 25 ng/mL beneath which the detected formestane is considered as being endogenous and no further investigation on GC-C-IRMS is required. Samples with urinary formestane concentrations above 25 ng/mL and beneath the WADA 150 ng/mL MRPL are forwarded to IRMS. Data collected from the testosterone and androstenedione excretion studies together with the results from the endogenous population suggests that this 25 ng/mL threshold provides a good balance between a sufficiently large detection window and not having to perform unnecessary IRMS analyses on negative urine samples.

ISBN:9783868840391

Toegankelijkheid:Closed