Advanced Urine Test Boosts Detection of Mid-Sized Doping Peptides

The landscape of performance-enhancing drugs (PEDs) is constantly evolving, with athletes increasingly turning to peptides due to their potent effects and perceived lower detectability. Traditional anti-doping methods often struggle with the diverse chemical properties and low concentrations of these compounds, particularly those in the 2-10 kDa molecular weight range. This creates a significant challenge for maintaining fair play in sports. This study addresses the critical need for sensitive and specific analytical methods capable of reliably identifying mid-sized peptidic analytes in doping control urine samples.

The developed LC-MS/MS method demonstrated exceptional performance for detecting peptides in the target molecular weight range. It achieved impressive limits of detection (LODs), with several key peptidic analytes quantifiable down to 0.1-0.5 ng/mL, representing a 2-fold improvement in sensitivity compared to existing techniques for this size class. The method exhibited excellent linearity over a broad concentration range (R² > 0.995) and high specificity, with minimal interference from endogenous urine components, leading to a 98% specificity rate. The study successfully established a robust analytical platform capable of identifying a diverse array of mid-sized doping peptides with recoveries consistently above 85% across various concentrations, significantly enhancing the anti-doping arsenal. This robust performance ensures reliable identification of exogenous peptides, even at low physiological concentrations, providing a substantial advantage over previous methods that often missed these challenging analytes. The overall method precision, expressed as relative standard deviation, was consistently below 10% for all validated peptides.