Read the lines that change the meaning

1. Lot and laboratory

The lot or batch on the label should be the lot on the report. The laboratory’s name should be specific enough to find the organization. A report that cannot be tied to a container is not a record of that container.

2. Identity

Retention time against a reference standard says the peak showed up where the standard showed up under that method. A mass from ESI-MS or LC-MS says the observed mass matches the expected mass, within the laboratory’s stated tolerance. Retention time alone is weaker. Sequence-level confirmation is a further claim and should be named as such if it is made. Details are on the LC-MS page.

3. Purity is not content

HPLC purity is typically the area of the main peak divided by the area the method counts, expressed as a percent. Content, assay, or “mg per vial” is how much of the substance is present. A vial can be highly pure and still contain less mass than the label states. Both numbers belong on the report if both questions matter. The HPLC page covers the chromatogram.

4. The picture, not only the percent

A chromatogram shows whether the percent came from a clean baseline and a separated peak or from a crowded trace. If the report quotes a purity and withholds the chromatogram, say so in your own notes. Absence is a fact.

5. Endotoxin and microbes

An endotoxin number, often in EU per vial or per milliliter, comes from a method such as LAL. A sterility line is a different test. A PCR screen, a TAMC/TYMC count, and a method described as USP <71> are not interchangeable phrases. If the line you need is missing, the certificate does not answer that question. See endotoxin and sterility.

6. Signatures and a way to check

A signature, a report number, and a public lookup or QR code give you a path back to the issuer. Use the issuer’s own verification page for that laboratory. Do not treat a lookup built for one laboratory as proof of another laboratory’s PDF.