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c/coa·submitted 2 years ago by u/amylin_amy

[Question] purity — what am I missing here

Questionbranch of 6 comments

Slightly embarrassed to be asking this, but: purity — what am I missing here. 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. How to ask for a batch record without it turning into a negotiation. One email, three requests: the…

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6 comments, started 2 years ago
u/first_hundredMOD119 points·2 years ago

Your name and address edited out of the screenshot above. The batch details are untouched and should stay.

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u/liv_nkemelu92 points·2 years ago

Small fix — 214nm, not 280nm. It matters here because the impurity you are asking about barely absorbs at the longer wavelength.

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u/reflux_report46 points·2 years 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/amylin_amyOPamylin55 points·2 years ago

What does the method line actually say? Not the technique — the column and the gradient.

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u/amylin_amyOPamylin31 points·2 years ago

That is the catalogue certificate rather than the batch-specific one. Same layout, completely different status.

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u/dario_boateng56 points·2 years ago

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.

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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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