unpopular opinion: most of what gets said here about COA is guesswork
The title is the argument: unpopular opinion: most of what gets said here about COA is guesswork. Here is the rest of it. The PDF creation date being later than the analysis date is usually a re-issue or a re-export. It is worth one question and it is not evidence of anything on its own. Ask what the stability…
Related substances itemised individually is a much stronger document than a single total, because it tells you the shape of the impurity profile rather than its size.
Area percent is the peak area of your compound over the total integrated area, at one wavelength, on one gradient. It is a relative measure of what the detector saw, not a mass fraction of the vial.
This. Area percent answers "what fraction of what the detector saw was the peak I wanted", and people read it as "how much peptide is in the vial".
redact your own name, never the batch details
Are the related substances itemised or is it a single total?
Related substances itemised individually is a much stronger document than a single total, because it tells you the shape of the impurity profile rathe
amara_halonen has the distinction right — one is a fraction of the detector signal, the other is a fraction of the mass.
Yes. The structure of the document matters at least as much as the number printed on it.
The document I was worried about turned out to be a re-issue with a later creation date. Asked, got the original, entirely ordinary.
Cosigning. The batch identifier is load-bearing, and a certificate that cannot be tied to the vial in your hand is not about your vial.