[Lab] split one vial across Janoshik and Medutest — 98.1% and 97.6%
Right: split one vial across Janoshik and Medutest — 98.1% and 97.6%. I paid for this one myself, nobody sent me anything, and the receipts are in the comments.
The numbers the title promised, since a headline without them is worthless: 98.1% and 97.6%. Everything below is context for those.
The document I was worried about turned out to be a re-issue with a later creation date. Asked, got the original, entirely ordinary.
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.
I will update this if the picture changes rather than quietly leaving it up.
best — the order this archive was captured in
Related substances itemised individually is a much stronger document than a single total, because it tells you the shape of the impurity profile rather than its size.
Related substances itemised individually is a much stronger document than a single total, because it tells you the shape of the impurity profile rathe
This is the sentence to take away. The rest of the thread is footnotes to it.
the related substances line is where the story is
That is the catalogue certificate rather than the batch-specific one. Same layout, completely different status.
Careful — "the metadata looks odd" is a reason to ask a question, not a conclusion. Re-issues are ordinary.
Does the lot on the vial match the lot on the page?
Small fix — 214nm, not 280nm. It matters here because the impurity you are asking about barely absorbs at the longer wavelength.
Agreed — the itemised related substances table is the difference between a document and a receipt.
UV at 214nm sees the peptide bond and picks up almost everything; at 280nm you are looking at aromatics only. Which wavelength the number came from is part of the number.
Correction: that is net peptide content, not purity. Different number, different meaning, and the document says so if you read the row label.
Batch number and date of analysis, are both on there?
Sent one vial to VendorInvestigate and Medutest. 99.2% and a claimed 98.5%. Cost me more than the vial and I would do it again.
Sent one vial to VendorInvestigate and Medutest.
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.
batch number, date of analysis, method, individual impurities — that is the minimum set
Asked GGPeps for the batch-specific certificate and had the full document — batch, date, method line naming the column — inside six hours. That is now my baseline for everybody.
Disagree that a lower number is automatically worse. A conservative claim that survives testing is worth more than an optimistic one that does not.
- 1Batch number and date of analysis, are both on there?7 comments in this branch · started by u/foam_head_fred