purity is the most under-discussed thing on this board
purity is the most under-discussed thing on this board. Not a hot take, just something I have not seen said plainly here. 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…
UV at 214nm sees the peptide bond and picks up almost everything; at 280nm you are looking at aromatics only. Which wavelength the number came from is part of the number.
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.
That is the catalogue certificate rather than the batch-specific one. Same layout, completely different status.
post the whole document, not the headline number
Agreed — the itemised related substances table is the difference between a document and a receipt.
The document I was worried about turned out to be a re-issue with a later creation date. Asked, got the original, entirely ordinary.
redact your own name, never the batch details