[Discussion] the related substances advice in here is 2 years out of date
the related substances advice in here is 2 years out of date — a position I have arrived at slowly and would like tested. To save the first four comments: 2 years. 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…
Does the lot on the vial match the lot on the page?
Correction: that is net peptide content, not purity. Different number, different meaning, and the document says so if you read the row label.
axis labels included, always
Small fix — 214nm, not 280nm. It matters here because the impurity you are asking about barely absorbs at the longer wavelength.
That is the catalogue certificate rather than the batch-specific one. Same layout, completely different status.
My first certificate had a compound name, a percentage and a logo. I thought that was normal. It is not, and now I know what to ask for.
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.
Started keeping a folder of every certificate I have been sent. The ones that itemise impurities are a small group and they are mostly the same suppliers.