Positions 101–125 of 130.
how much of what we believe about batch actually comes from related substances threads — that is what I am asking, and I have already read the wiki twice. Ask what the…
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…
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…
related substances are doing more work than we give it credit for, and I am aware this is a minority view on this board. Sent one vial to VendorInvestigate and…
Vendor-level purity averages over time, built from independent results rather than vendor claims. Transparent methodology, open dataset.
Browse resultsSlightly embarrassed to be asking this, but: purity — what am I missing here. My first certificate had a compound name, a percentage and a logo. I thought that was…
SSA 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…
Genuine question, and the title is the question: how much of what we believe about COA actually comes from area percent threads. My first certificate had a compound…
the purity rule is doing its job and people should stop complaining. Disagreement welcome, but bring a concrete alternative wording. UV at 214nm sees the peptide bond…
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…
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…
Putting this to the board: proposal — a flair for batch posts. Why the same vial can honestly produce three different numbers. Purity by area percent is relative to…
the related substances advice in here is 3 years out of date.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,…
the batch rule is doing its job and people should stop complaining. Short post, long comment section, probably. Area percent is the peak area of your compound over the…
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…
unpopular opinion: most of what gets said here about water content is guesswork, and I am aware this is a minority view on this board. UV at 214nm sees the peptide bond…
Reference standards, analytical reagents and system-suitability material. If you are running your own method, start with a known.
Reference standardsThe 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…
16th independent test on WXT — 99.3% on a claimed 98.5%, and the trend is the interesting part. I will put the method line and the batch identifier up front because…
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…
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…
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 — 3 things I got wrong before I got it right. Not a hot take, just something I have not seen said plainly here. Net peptide content is the fraction of the powder…
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…
three years of purity threads, summarised so you do not have to read them, and I am aware this is a minority view on this board. The four things a certificate must…
Title says it — is 96.8% area% actually fine or am i being sold a rounding error — so here is the boring supporting detail that makes it worth anything. 96.8%. Those…
Posting this as a discussion rather than a claim: acetate counterion is why your 10mg vial has 8.7mg of peptide. Numbers, in the order they matter: 10mg and 8.7mg. UV…
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.
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