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c/coa·submitted 1 year ago by u/ignacio_silva

help me understand area percent, I have read the wiki twice

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help me understand area percent, I have read the wiki twice. If this has been answered properly somewhere, link me and I will delete. How to ask for a batch record without it turning into a negotiation. One email, three requests: the batch-specific certificate for lot X, the method line behind it, and the storage…

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6 comments, started 1 year ago
u/fatima_wojcik51 points·1 year ago

the counterion is part of the mass you paid for

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u/amira_dumitru14 points·1 year ago

Agreed on asking for the storage condition. It is one line and it changes how you read the entire stability claim.

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u/zaid_balogun11 points·1 year ago

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.

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u/emil_agyeman8 points·1 year ago

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.

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u/dario_boateng2 points·1 year ago

chromatogram or it did not happen

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u/low_appetite_lisa2 points·1 year ago

the lot on the vial has to match the lot on the page

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About c/coa

How to read a certificate of analysis and what it does and does not tell you. Area% versus mass%, identity versus quantity, water content, related substances, acetate counterions, and the difference between a vendor-supplied COA and an independent test on the vial you actually received.

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