Development and validation of a semi-quantitative ultra-high performance liquid chromatography-tandem mass spectrometry method for screening of selective androgen receptor modulators in urine

A semi-quantitative method was developed to monitor the misuse of 15 SARM compounds belonging to nine different families, in urine matrices from a range of species (equine, canine, human, bovine and murine). SARM residues were extracted from urine (200 μL) with tert-butyl methyl ether (TBME) without further clean-up and analysed by ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS). A 12 min gradient separation was carried out on a Luna Omega Polar C18 column, employing water and methanol, both containing 0.1% acetic acid (v/v), as mobile phases. The mass spectrometer was operated both in positive and negative electrospray ionisation modes (ESI±), with acquisition in selected reaction monitoring (SRM) mode. Validation was performed according to the EU Commission Decision 2002/657/EC criteria and European Union Reference Laboratories for Residues (EU-RLs) guidelines with CCβ values determined at 1 ng mL⁻¹, excluding andarine (2 ng mL⁻¹) and BMS-564929 (5 ng mL⁻¹), in all species. This rapid, simple and cost effective assay was employed for screening of bovine, equine, canine and human urine to determine the potential level of SARMs abuse in stock farming, competition animals as well as amateur and elite athletes, ensuring consumer safety and fair play in animal and human performance sports.