In the pre-clinical research sector, confirming chemical identity and purity is vital. A Certificate of Analysis (COA) details the results of analytical chemistry assays performed on a specific batch of synthetic peptide. Independent third-party COAs serve as objective evidence that the compounds meet quality specifications before starting a study.
This article explains how to analyze a COA, focusing on High-Performance Liquid Chromatography (HPLC) chromatograms and Mass Spectrometry (MS) readouts to verify purity and molecular mass confirmation.
Why Third-Party COAs Matter
Peptides are synthesized chemically via Solid-Phase Peptide Synthesis (SPPS). Because incomplete couplings, deletion sequences, and side reactions can introduce impurities, manufacturers must perform analytical checks. A third-party testing facility independently validates these metrics, providing unbiased reports to researchers. You can view all MHS Longevity batch reports on our Third-Party Test Results page.
1. High-Performance Liquid Chromatography (HPLC) and Purity
HPLC measures peptide purity by separating components in a liquid mixture based on their hydrophobic interactions with a column. As the sample flows, different chemical species pass through at different rates, eluted and recorded by a UV detector.
The HPLC report is presented as a chromatogram—a graph of absorbance peaks over time. The main peak represents the target peptide, while smaller peaks represent impurities. Purity is calculated using Peak Area Integration (the area under the main peak divided by the total area of all integrated peaks). For pre-clinical research, a purity threshold of 99%+ is the target standard.
2. Mass Spectrometry (MS) and Molecular Identity
While HPLC measures purity, Mass Spectrometry (MS) confirms identity. MS vaporizes and ionizes the peptide sample, measuring the mass-to-charge (m/z) ratio of the ions. The observed molecular mass (typically represented as [M+H]+ or [M+2H]2+ ions) is compared with the theoretical molecular weight calculated from the amino acid sequence.
For example, if a research peptide has a theoretical molecular weight of 3567.8 g/mol, the mass spectrometry scan should show a corresponding peak matching this mass, confirming the sequence is correct. Mass spectrometry ensures you are working with the correct compound, preventing synthesis errors from going undetected.
Key Takeaways for COA Review
Key Takeaways
- HPLC chromatograms verify purity by calculating the integrated area under the main peak
- Mass Spectrometry (MS) confirms molecular identity by measuring the mass-to-charge ratio of ionized peptide fragments
- Ensure the lot number on the COA matches your product vial for complete batch traceability
- Verify that the testing laboratory is named, independent, and dated within a reasonable window
- All MHS Longevity compounds undergo third-party verification to guarantee 99%+ purity
