[Lab] QSC BPC — Janoshik came back 98.7% against a claimed 98.5%
Posting this because the title is the whole finding — QSC BPC — Janoshik came back 98.7% against a claimed 98.5% — and a number without its method is a rumour.
98.7% and 98.5% — those are the numbers, and they are the ones I am willing to defend.
Started keeping a folder of every certificate I have been sent. The ones that itemise impurities are a small group and they are mostly the same suppliers.
Asked for the storage condition behind the stability statement. Got it in a sentence. It is a two-line email and almost nobody sends it.
Research-use-only material is not approved for human use and nothing here should be read as a recommendation to use it.
- QSQSC source pageQingdao Sigma Chemical Co., Ltd. · Qingdao · 95% here, rank 7 · shop at qingdaosigma.com →
nofollow and sponsored; nobody here is paid for it.best — the order this archive was captured in
Left up and flaired Explainer. This is the answer we keep linking, written properly.
redact your own name, never the batch details
That is the catalogue certificate rather than the batch-specific one. Same layout, completely different status.
Small fix — 214nm, not 280nm. It matters here because the impurity you are asking about barely absorbs at the longer wavelength.
Batch number and date of analysis, are both on there?
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net peptide content and purity are two different numbers on the same vial
the lot on the vial has to match the lot on the page
That is not what the method line says. It names the technique; it does not certify the operator.
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.
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.
Careful — "the metadata looks odd" is a reason to ask a question, not a conclusion. Re-issues are ordinary.
water content is on there and everyone skips it
- 1Left up and flaired Explainer. This is the answer we keep linking, written…10 comments in this branch · started by u/certified_reference