c/coa · created 18 Aug 2023
Certificates of analysis, decoded. Post the whole document, not the headline number.
The claim in the title is exactly the claim I am making: WXT vs JEEP on the same compound, same month — both cleared 97.0%. Nothing implied beyond it. Pulling the…
Result first, context after: GL Biochem vs GGPeps on the same compound, same month — both cleared 97.5% . Everything below is how it was ordered, stored and sent.…
purity is the most under-discussed thing on this board. Not a hot take, just something I have not seen said plainly here. Net peptide content is the fraction of the…
why does nobody talk about water content. Searched first, found three threads that contradict each other, hence the post. Asked for the storage condition behind the…
Send the vial, get the number. Third-party purity and identity testing, results published to you regardless of what they say.
Test a vialSponsoredEst. 1998. ISO 9001 and cGMP, 1,500+ staff, 200+ patents. There is a fair chance the vial you are about to send for testing started here. Batch-specific COA as standard.
glbiochem.netHousekeeping: the area percent rule is doing its job and people should stop complaining. Water content 3.8%, acetate 6.2%, purity 99%, net peptide about 90% of label…
Short version of the title, which is already short: FGP BPC — PeptideMeter came back 99.6% against a claimed 99.0%. Longer version underneath. Since the title puts…
Slightly embarrassed to be asking this, but: how much of what we believe about batch actually comes from purity threads. Spent four months confusing area% and mass% in…
COA — what am I missing here. I am not trying to be the "source?" guy. I would just like a source. UV at 214nm sees the peptide bond and picks up almost everything; at…
reading area percent threads from 2024 and half of it aged badly. I have gone back and forth on this for months. UV at 214nm sees the peptide bond and picks up almost…
Question in the title, detail here: help me understand batch, I have read the wiki twice. The PDF creation date being later than the analysis date is usually a re-issue…
Thinking out loud about this: purity — 9 things I got wrong before I got it right. How to ask for a batch record without it turning into a negotiation. One email, three…
the area percent advice in here is 2 years out of date, which sounds obvious until you try to state the evidence for it. Since the title puts numbers in the shop…
Something I keep coming back to: purity — 6 things I got wrong before I got it right. My first certificate had a compound name, a percentage and a logo. I thought that…
the related substances advice in here is 3 years out of date. It is the sort of thing everyone half-believes and nobody writes down. 3 years — those are the numbers,…
Slightly embarrassed to be asking this, but: can we stop arguing about purity until somebody posts a number. My first certificate had a compound name, a percentage and…
Vendor-level purity averages over time, built from independent results rather than vendor claims. Transparent methodology, open dataset.
Browse resultsSSA vs TFC on the same compound, same month — both cleared 97.5%. I will put the method line and the batch identifier up front because that is what makes this…
Numbers in the title, numbers in the post. TFC vs SSA on the same compound, same month — both cleared 98.0%. Figures up front so nobody has to dig: 98.0%. Sent one vial…
genuine question about COA that I am slightly embarrassed to ask. I am not trying to be the "source?" guy. I would just like a source. The four things a certificate…
the certificate of analysis question that gets asked weekly, answered properly, which sounds obvious until you try to state the evidence for it. The PDF creation date…
is 99.1% actually fine or am I being sold a rounding error. That is the headline. The document, the batch and the service are below so you can argue with the method…
Question in the title, detail here: can we stop arguing about batch until somebody posts a number. Area percent is the peak area of your compound over the total…
Posting this because the title is the whole finding — HJ vs QYB on the same compound, same month — both cleared 97.0% — and a number without its method is a rumour.…
Posting this as a discussion rather than a claim: the water content question that gets asked weekly, answered properly. Why the same vial can honestly produce three…
unpopular opinion: most of what gets said here about certificate of analysis is guesswork — a position I have arrived at slowly and would like tested. LC-MS gives you…
The title is the argument: area percent is the most under-discussed thing on this board. Here is the rest of it. Started keeping a folder of every certificate I have…
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.
Certified reference materials for peptide identity and purity work.
sigmaaldrich.comSeveral compounds discussed on GLP Research Hub are sold for research use only and are not approved for human use anywhere. Nothing here is medical advice and none of it is written by your clinician. If a post reads like an instruction, treat it as a description of what one stranger did.
Reference