Third-party HPLC testing: what a CoA actually shows
A Certificate of Analysis (CoA) tells you what is in the vial. Every Veristas batch ships with one, and every product page links a sample. Reading it well is a basic research skill, so here is what each section means.
Identity: is it the right molecule
The first job of a CoA is confirming that the powder is the peptide on the label and not something close to it. Mass spectrometry answers this. It measures the molecular weight of the compound and compares it to the theoretical mass of the target sequence. A match within the expected tolerance confirms identity; a mismatch means the synthesis produced something else.
Purity: how much of it is the target
HPLC (high-performance liquid chromatography) answers the purity question. The instrument separates the sample into its components and reports each as a percentage of the total, read off the area under each peak. A purity of 99% means 1% of the vial contents is something other than the target peptide: truncated sequences, synthesis byproducts, or residual reagents. Veristas holds a 99% floor and reports purity to two decimals.
The HPLC trace itself is worth a look, not just the headline number. One clean dominant peak is the ideal. A cluster of small peaks beside it points to related impurities even when the total still rounds well.
The safety and composition lines
A full CoA carries more than identity and purity:
- Endotoxin (LAL) testing screens for bacterial endotoxin, reported in EU/mg.
- Water content (Karl Fischer) shows residual moisture, which affects stability.
- Acetate content reflects the counter-ion left from synthesis.
- Appearance confirms the physical form, usually a white lyophilized powder.
Why third-party matters
A CoA a vendor writes about its own product is a claim. A CoA from an independent, accredited lab is a check. Veristas uses third-party HPLC and mass spec so the testing is separated from the selling. When a batch sells out, the CoA URL stays live, so a result you cited in a protocol stays verifiable later.
If a supplier cannot produce a batch-specific CoA, you have no documented idea what you are working with. Browse the full catalog; every product carries one.
For in-vitro laboratory research only. Not for human or animal consumption.