Simplifying and expanding the screening for peptides <2 kDa by direct urine injection, liquid chromatography, and ion mobility mass spectrometry.
This study presents a sensitive and specific method for detecting low-molecular-mass peptides in urine, with limits of detection between 50 and 500 pg/mL.
Where it sits
this study against the rest of the aod-9604 corpusSummary and findings
This study presents a method for analyzing low-molecular-mass peptides in urine for doping control, specifically focusing on peptides under 2 kDa, including AOD-9604. The method achieves limits of detection between 50 and 500 pg/mL and demonstrates a linear working range from 0 to 10 ng/mL. The stability of the peptides was confirmed at -20°C for storage.
Abstract
The analysis of low-molecular-mass peptides in doping controls has become a mandatory aspect in sports drug testing and, thus, the number of samples that has to be tested for these analytes has been steadily increasing. Several peptides <2 kDa with performance-enhancing properties are covered by the list of prohibited substances of the World Anti-Doping Agency including Desmopressin, LH-RH, Buserelin, Triptorelin, Leuprolide, GHRP-1, GHRP-2, GHRP-3, GHRP-4, GHRP-5,GHRP-6, Alexamorelin, Ipamorelin, Hexarelin, ARA-290, AOD-9604, TB-500 and Anamorelin. With the presented method employing direct urine injection into a liquid chromatograph followed by ion-mobility time-of-flight mass spectrometry, a facile, specific and sensitive assay for the aforementioned peptidic compounds is provided. The accomplished sensitivity allows for limits of detection between 50 and 500 pg/mL and thus covers the minimum required performance level of 2 ng/mL accordingly. The method is precise (imprecision <20%) and linear in the estimated working range between 0 and 10 ng/mL. The stability of the peptides in urine was tested, and -20°C was found to be the appropriate storage temperature for sports drug testing. Finally, proof-of-concept was shown by analysing elimination study urine samples collected from individuals having administered GHRP-6, GHRP-2, or LHRH.
Background
The paper addresses the need for efficient screening methods for small peptides, which are often challenging to analyze due to their size and complexity. Previous methods may have limitations in sensitivity and specificity, making this study relevant for improving peptide detection in biological samples. AOD-9604 is referenced, but the focus is on methodological advancements rather than clinical applications.
Methods
Not reported in abstract.
Results
Not reported in abstract.
Interpretation
Not reported in abstract.
Key findings
- Not reported in abstract.
Limitations
- Not reported in abstract.