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c/coa·posted 2 years ago by u/ismael_eriksen

genuine question about certificate of analysis that I am slightly embarrassed to ask

COA Well Actually ×9 Cold Box ×2 Slow Clap ×2

Something I noticed reading old threads that I have not seen said out loud.

The advice on related substances in this community changed substantially around the start of last year, and nobody went back and updated the older posts. So depending on which thread the search engine hands you, you get two contradictory answers with the same confidence.

I have listed what I think the current consensus is below. Correct me — that is the point of posting it.

24,479 up / 18,234 down57% upvoted53 commentsid 3qbi012 Nov 2023

53 comments

19 in this archive, depth 4

best — the order this archive was captured in

u/ghrp_history-8 points·2 years ago

the method line is doing real work, not just window dressing

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u/purity_pedantanalytical651 points·2 years ago

the counterion is part of the mass you paid for

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u/tuva_aalto434 points·2 years ago

the batch number or it did not happen

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u/neha_erdogan292 points·2 years ago

the batch number or it did not happen

Counter-anecdote: opposite result, same dose. Which mostly tells us the variance is huge.

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u/soren_nkemelu103 points·2 years ago

axis labels included, always

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u/anecdata_annie187 points·2 years ago·edited

Water content was 3.8%, acetate was 6.2%, purity was 99%, but net peptide was only 90% of the label weight. Perfectly honest, just chemistry.

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u/aurel_boateng313 points·2 years ago

This is the correct framing. The COA structure matters as much as the number.

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u/aurel_boateng183 points·2 years ago

redact your own name, not the vendor's batch details

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u/ismael_eriksenOP118 points·2 years ago

Strongly agree. Mass% and area% are answering different questions on the same document.

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u/emeka_chowdhury31 points·2 years ago

PDF metadata is checkable in fifteen seconds

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u/emil_agyeman288 points·2 years ago

PDF metadata is checkable in fifteen seconds

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u/bastian_moreau201 points·2 years ago·edited

The practical rule people converge on is 28 days at fridge temperature after first puncture, and that comes from the preservative, not the peptide.

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u/coa_janitormod · c/coa91 points·2 years ago

Titration speed is a side-effect dial far more than an efficacy dial.

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u/nadia_fonseca45 points·2 years ago

no "is this good?" without saying what the compound and claimed purity are

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u/low_appetite_lisa29 points·2 years ago

redact your own name, not the vendor's batch details

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u/valeria_karlsen25 points·2 years ago

the batch number or it did not happen

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u/coa_janitormod · c/coa19 points·2 years ago·edited

That is net peptide content, not purity. Different number, different meaning.

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u/karma_irrelevant8 points·2 years ago

axis labels included, always

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u/dead_space_doug83 points·2 years ago·edited
no
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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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c/coa rules
  1. Post the full document. Cropped COAs that hide the batch number or date get removed.
  2. Redact your own name and order id, not the vendor's batch details.
  3. No "is this good?" without saying what the compound and claimed purity are.
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