Mass Spectrometry for the Detection of Endogenous Steroids and Steroid Abuse in (Race) Horses and Human Athletes

The higher the pressure to win, the more athletes are inclined to take steps to improve one’s performance through questionable means. To minimize this, strict anti‐doping and medication rules are being enforced. All human and equine athletes are regularly subjected to doping analysis to prevent abuse of forbidden substances from affecting their performance. Anabolic‐androgenic steroids (AASs) have been part of the forbidden substances list for years, because of their muscle building and performance‐enhancing capacities and possible side effects. For most of the AAS, zero‐tolerance is held. However, some AASs can be endogenous to the athletes, such as for example testosterone in males. These endogenous steroids can render it very difficult to reveal steroid abuse. Specific mass spectrometric (MS) methods, including ultra‐high performance liquid chromatography‐MS (UHPLC‐MS/MS), high resolution mass spectrometry (HRMS) and gas chromatography–combustion‐isotope ratio MS (GC‐C‐IRMS), have been put forward to overcome these analytical difficulties. Currently, high‐tech metabolomic methods are being used to build athlete specific biological passports. In the near future, these passports might allow putting a stop to abuse, by staying ahead of the cheats. These are bright prospects, leading towards clean and fair sports competitions worldwide.