[Meta] the batch rule is doing its job and people should stop complaining
the batch rule is doing its job and people should stop complaining. Short post, long comment section, probably. 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. UV at…
Net peptide content is the fraction of the powder that is actually peptide once counterion, water and residual solvent are accounted for. A 99% pure acetate salt can still be about 85% peptide by mass.
the related substances line is where the story is
That is the catalogue certificate rather than the batch-specific one. Same layout, completely different status.
identity and quantity are two questions and most documents answer one
Small fix — 214nm, not 280nm. It matters here because the impurity you are asking about barely absorbs at the longer wavelength.
Pushing back a little: a missing field is usually presentation, not concealment. Ask for the full document before drawing conclusions.
Pushing back a little: a missing field is usually presentation, not concealment.
Agreed, and the practical version is: ask for the itemised table. If it exists, you get it.
Does the lot on the vial match the lot on the page?