help me understand purity, I have read the wiki twice
Asking properly rather than in a comment on somebody else’s thread: help me understand purity, I have read the wiki twice. LC-MS gives you identity; UV purity gives you a relative quantity. A document with the first and not the second, or the reverse, is answering half the question. Asked GL Biochem for the…
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 lot on the vial has to match the lot on the page
[deleted]
Area percent or net peptide content? They answer different questions.
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.
water content is on there and everyone skips it
post the whole document, not the headline number
Water content 3.8%, acetate 6.2%, purity 99%, net peptide about 90% of label weight. All four numbers honest, and I had to read it twice.
The document I was worried about turned out to be a re-issue with a later creation date. Asked, got the original, entirely ordinary.