Save up to 20% on bulk orders · Free shipping over $200
Quick answer: HPLC (high-performance liquid chromatography) measures purity: it separates a sample into its components and reports what share of the material is the target peptide. Mass spectrometry (MS) confirms identity: it measures the molecular mass and checks it against the expected value for that sequence. The two tests answer different questions, so a reliable Certificate of Analysis includes both.
In reversed-phase HPLC, the most common method for peptides, a dissolved sample is pumped through a column packed with a hydrophobic material. Different molecules stick to the column to different degrees, so they exit at different times. A detector, usually measuring UV absorbance, records each component as a peak on a chromatogram.
Purity is typically calculated as the area of the main peak divided by the total area of all peaks. A result of 99% means the target peptide makes up 99% of the detected signal. Impurities from synthesis, such as truncated or incomplete sequences, show up as smaller peaks.
HPLC shows that one component dominates the sample, but it does not prove which molecule that component is. A different peptide could also produce a single clean peak.
Mass spectrometry ionizes molecules and measures their mass-to-charge ratio. For peptides, techniques such as electrospray ionization (ESI) or MALDI are common. The result is compared with the theoretical molecular mass calculated from the amino acid sequence. When the observed mass matches the expected mass within the instrument’s tolerance, identity is confirmed.
A mass match confirms the molecule is present, but on its own it is not a precise measure of how much of the sample is that molecule. That is the job of HPLC.
| HPLC | Mass spectrometry | |
|---|---|---|
| Main question answered | How pure is it? | What is it? |
| Typical result | Purity as a percentage | Observed vs expected molecular mass |
| Detects | Impurities and related substances | Wrong or modified molecules |
| Limitation | Does not confirm identity | Not a precise purity measure |
Together, the two methods close each other’s gaps: mass spectrometry proves the right molecule is present and HPLC proves it makes up nearly all of the sample. LC-MS instruments combine both in one run. At Pure Health Sciences, every lot is tested by an independent, accredited laboratory with both methods, and only lots at 99% purity or higher are listed.
HPLC separates a sample to measure purity as a percentage, while mass spectrometry measures molecular mass to confirm the identity of the compound.
It means the main peak, the target peptide, accounts for 99% of the total signal detected by the HPLC instrument, with impurities making up the rest.
LC-MS couples liquid chromatography with mass spectrometry in one instrument, so components are separated and their masses measured in the same analysis.
Yes. Every lot is tested by an independent, accredited laboratory for purity by HPLC and identity by mass spectrometry before it is listed.
This article is for educational purposes for laboratory researchers. Pure Health Sciences products are sold for in vitro research use only and are not for human or veterinary use.
Every lot ships with its Certificate of Analysis. Free tracked shipping over $200 CAD.
Ordering research peptides in Canada? Use this seven-point checklist to judge supplier quality, documentation, shipping and research-use compliance before you buy.
HPLC measures how pure a peptide sample is, while mass spectrometry confirms what the molecule is. Here is how each test works and why a trustworthy CoA includes both.
Lyophilized peptides last longest sealed, frozen and dry. This lab guide covers storage temperatures, light and moisture control, and how to handle vials when you open them.
Pure Health Sciences supplies research compounds only to qualified researchers and laboratories. Please confirm before continuing.
Not a researcher? Leave this site. See our terms.