HPLC and Mass Spectrometry Explained
Published October 15, 2026
Two lab methods do most of the work behind a peptide COA: high performance liquid chromatography (HPLC) and mass spectrometry (MS). Together they answer two different questions. HPLC asks how pure the sample is. Mass spectrometry asks whether it is the right compound.
HPLC: measuring purity
In HPLC, a dissolved sample is pushed under high pressure through a column packed with fine material. Different substances travel through the column at different speeds, so they come out at different times. A UV detector at the end records each substance as a peak on a graph called a chromatogram.
Purity is calculated by comparing the area of the main peak to the total area of all peaks. A result of 99.5% means the target compound accounts for 99.5% of what the detector measured.
Mass spectrometry: confirming identity
Mass spectrometry measures the mass of molecules. The sample is given an electric charge, and the instrument sorts the charged molecules by their mass to charge ratio. Every compound has a known molecular weight, so the peaks either match the expected values or they do not.
Peptides often appear more than once in the results, carrying one, two, or more extra charges. These show up as related peaks, labeled with notations like [M+H]+ and [M+2H]2+, that all point back to the same molecular weight.
Why both matter
A sample can be very pure and still be the wrong compound, and a sample can be the right compound but full of impurities. That is why a complete COA reports both. Freedom Diagnostics runs HPLC with UV detection coupled with mass spectrometry, often written as LC-MS, so purity and identity are measured in the same analysis.
Where to see the results
Every posted DryV COA shows the chromatogram and mass confirmation for that lot. You can browse them on our Lab Results page, or read How to Read a COA for a section by section walkthrough.
Related Products
All products sold by DryV Life are supplied for laboratory research use only. They are not for human or animal consumption and are not intended to diagnose, treat, cure, or prevent any disease or condition. These products have not been evaluated by the FDA.