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c/coa·submitted 4 months ago by u/andres_restrepo

help me understand purity, I have read the wiki twice

Questionbranch of 9 comments

Trying to settle this properly because the thread from last year went in circles. The claim: certificate of analysis matters. The counter-claim: it is measurement error. Both sides have been asserting it confidently for about 10 months without either producing anything. What would actually settle it is 31 people…

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9 comments, started 4 months ago
u/anecdata_annie59 points·4 months ago

Disagree. What you are describing is consistent with certificate of analysis, not with what you concluded.

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u/joaquin_ivaturi24 points·4 months ago

Yeah, 96.8% area is not the problem, the missing impurity breakdown is the problem.

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u/certified_referenceQC13 points·4 months ago

the counterion is part of the mass you paid for

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u/yannick_haddad4 points·4 months ago

post the whole document, not the headline number

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u/rohan_steiner6 points·4 months ago

Water content on the document? That affects your concentration math.

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u/spreadsheet_gremlindata5 points·4 months ago

purity and net content are two different numbers, same vial

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u/milos_trevino47 points·4 months ago·edited

What were the related substances listed individually?

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u/andres_restrepoOP19 points·4 months ago

Asked HJ for the batch-specific COA and they sent it within six hours, full document, batch number, date, everything. That is the baseline.

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u/isabela_nilsen49 points·4 months ago

Batch number and date of analysis? Both are load-bearing.

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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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