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

[Lab] split one vial across VendorInvestigate and PeptideMeter — 97.2% and 98.4%

Labbranch of 7 comments

The claim in the title is exactly the claim I am making: split one vial across VendorInvestigate and PeptideMeter — 97.2% and 98.4%. Nothing implied beyond it. Pulling the figures out of the title: 97.2% and 98.4%. All of it is written down as it happened rather than reconstructed. The four things a certificate must…

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7 comments, started 1 year ago
u/sig_figs_sammod · analytical106 points·1 year ago

Flairing this Explainer. It answers the question properly rather than asking it.

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u/coa_collectorarchivist132 points·1 year ago

Flairing this Explainer.

Adding the bit that always gets missed: the lot on the vial has to match the lot on the page, or none of this applies to your material.

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u/sofia_ferreira33 points·1 year ago

post the whole document, not the headline number

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u/purity_pedantanalytical7 points·1 year ago

This. Area percent answers "what fraction of what the detector saw was the peak I wanted", and people read it as "how much peptide is in the vial".

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[removed]23 points·1 year ago

[removed by moderator]

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u/first_hundredOP16 points·1 year ago

Batch number and date of analysis, are both on there?

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u/milos_vanhecke82 points·1 year ago

ask for the storage condition the stability statement was written against

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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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