Novel Nano LC-MS Method Boosts Detection of Growth Hormone Peptides in Urine

Growth hormone releasing hormone (GHRH) and its synthetic analogs, such as Sermorelin and Tesamorelin, are potent stimulators of endogenous growth hormone (GH) production. Due to their anabolic and performance-enhancing effects, these peptides are frequently misused in sports, leading to their classification as prohibited substances by anti-doping agencies. Current detection methods often struggle with the low concentrations and short half-lives of these peptides in biological matrices, especially urine. This study addresses the critical need for highly sensitive and specific analytical methods to detect GHRH and its analogs in urine for anti-doping purposes.

The developed nano LC-Q/Orbitrap MS method demonstrated exceptional sensitivity and specificity for GHRH and its analogs. The limits of detection (LODs) were remarkably low, with Sermorelin detected at 5 pg/mL, Tesamorelin at 8 pg/mL, and GHRH at 12 pg/mL in urine. The method exhibited excellent linearity over the tested range of 0.1-100 ng/mL, with correlation coefficients (R²) consistently above 0.999 for all analytes. Average recovery rates from spiked urine samples were high, ranging from 95.2% to 103.8%, indicating minimal matrix effects. Intra-day and inter-day precision were both below 5% relative standard deviation. The method achieved unprecedented sensitivity for Sermorelin, detecting it at concentrations as low as 5 pg/mL in urine, representing a 3-fold improvement in sensitivity compared to previously published LC-MS/MS methods.