More usefully, the certificate is not the answer to your question; it is a data point that you need to combine with other information to build an answer.
The field you have least reason to trust is the one that looks most impressive, because appearance and accuracy are not correlated.
Reconciling gross mass to label claim
| Component | Typical share | Counted in purity? | Counted in content? |
|---|
| Target peptide | 88–94 % | Yes, as main peak | Yes |
| Related impurities | 1–3 % | Yes, as other peaks | No |
| Counter-ion (TFA or acetate) | 2–8 % | No | No |
| Residual water | 2–6 % | No | No |
| Bulking agent, if present | 0–40 % | No | No |
The underlying point is that the laboratory name and accreditation status can be checked in real time against the testing service's own register, and that two-minute check catches substituted certificates.
Be careful not to over-read this — a certificate that is imperfect is not worthless, it is just a starting point for thought rather than an endpoint.
If the certificate does not trace to your vial, it is not evidence about your vial.
edited 4 Oct 2024 by nynke_dekker — added the citation requested in comments