Chromatographic-mass spectrometric analysis of peptidic analytes (2-10 kDa) in doping control urine samples.
This study developed and validated a unified chromatographic-mass spectrometric (LC-MS) method for detecting a broad range of prohibited peptide drugs (molecular mass 2–10 kDa) in doping control urine samples. The target analytes spanned five categories: insulins (human and animal-derived, including several analogues and a metabolite), growth hormone-releasing hormones (GHRHs) and their metabolites, insulin-like growth factors (IGF variants), synacthen, gonadorelin, and mechano growth factors. A key goal was simplifying sample preparation by consolidating what are traditionally separate, complex analytical workflows into a single procedure, controlled by five internal standards—one per peptide category. The method was validated as an initial testing procedure and shown to meet nearly all World Anti-Doping Agency (WADA) Minimum Required Performance Levels (MRPLs). As a proof of principle, the method was applied to authentic post-administration urine samples from human subjects dosed with insulins and gonadorelin, demonstrating real-world detection capability. Limitations include that human subject data are limited to proof-of-concept post-administration samples rather than a controlled efficacy or pharmacological trial, and the study's primary focus is analytical method development rather than clinical outcomes.