A Certificate of Analysis is the only document that turns a vial of white powder into a known quantity. This is how to read the one Aureum publishes for every lot, line by line, and what each line can and cannot tell you.
Where to find it
Every vial label carries a QR code. It resolves to the lot’s own page under aureumpeptides.com/coa/, which is the same page you reach by typing the lot number into the portal. The page is public, indexed, and does not change once the lot is released; corrections are dated.
1. Lot number
A lot is one synthesis and one fill. Two vials with the same lot number came from the same batch of material and were tested together. If a result matters to your work, record the lot number with it; the compound name alone identifies nothing.
2. Purity (HPLC)
Reverse-phase high-performance liquid chromatography separates the peptide from everything else that absorbs at the detection wavelength. Purity is the area of the main peak as a percentage of all peak area. Three things it does not tell you:
- It says nothing about water or counter-ion content, which do not absorb. A 99% pure lyophilized cake can still be 80% peptide by mass.
- Two peptides with the same retention time will be counted as one peak. Purity is not identity.
- The figure depends on the method: column, gradient, wavelength. The method line matters when you compare two certificates.
3. Identity (mass spectrometry)
MS reports the observed molecular weight and the certificate compares it with the theoretical value calculated from the sequence. Agreement within the instrument’s tolerance confirms that the main peak is the intended molecule. Purity without identity is a number about an unknown; identity without purity is a name on a mixture. You need both.
4. Net peptide content
Where a lot has been assayed for it, the certificate states net peptide content: the fraction of the cake’s mass that is peptide, after water and counter-ions. This is the figure to use when you calculate a concentration. The concentration calculator takes net content as its first input for exactly this reason.
5. Laboratory, report reference, date
The certificate names the laboratory that ran the tests and quotes its report reference. A reference that cannot be traced back to a laboratory is decoration, not documentation. Where the laboratory publishes its own copy, the two should agree.
What a certificate is not
It is a statement about a lot of chemical material: what it is, how much of it there is, and how clean it is. It is not a statement about what the material does, and Aureum’s certificates make none. Research materials are supplied for in-vitro laboratory use only, not for human or veterinary use.
Questions about a specific lot: contact@aureumpeptides.com with the lot number in the subject line.