Positions 76–100 of 130.
area percent — what am I missing here. Searched first, found three threads that contradict each other, hence the post. Asked QSC for the batch-specific certificate and…
The claim in the title is exactly the claim I am making: is 99.0% actually fine or am I being sold a rounding error. Nothing implied beyond it. To save the first four…
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…
we are measuring area percent at the wrong time and calling it noise. Not a hot take, just something I have not seen said plainly here. Net peptide content is the…
Reference standards, analytical reagents and system-suitability material. If you are running your own method, start with a known.
Reference standardsThe title is the argument: related substances — 9 things I got wrong before I got it right. Here is the rest of it. The PDF creation date being later than the analysis…
the purity advice in here is 3 years out of date. It is the sort of thing everyone half-believes and nobody writes down. Hard numbers: 3 years. Anything softer than…
Something I keep coming back to: unpopular opinion: most of what gets said here about area percent is guesswork. Spent four months confusing area% and mass% in every…
the batch question that gets asked weekly, answered properly. I have gone back and forth on this for months. Asked for the storage condition behind the stability…
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…
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…
three years of COA threads, summarised so you do not have to read them. It is the sort of thing everyone half-believes and nobody writes down. Asked GL Biochem for the…
The title is the argument: purity is doing more work than we give it credit for. Here is the rest of it. The PDF creation date being later than the analysis date is…
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…
the related substances advice in here is 2 years out of date — a position I have arrived at slowly and would like tested. To save the first four comments: 2 years. Net…
Posting this because the title is the whole finding — JEEP vs WXT on the same compound, same month — both cleared 98.5% — and a number without its method is a rumour.…
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.netPosting 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…
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…
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…
Posting this as a discussion rather than a claim: three years of water content threads, summarised so you do not have to read them. Why the same vial can honestly…
help me understand area percent, I have read the wiki twice. If this has been answered properly somewhere, link me and I will delete. How to ask for a batch record…
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…
Housekeeping: 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…
The claim in the title is exactly the claim I am making: split one vial across VendorInvestigate and PeptideMeter — 97.2% and 98.4%. Nothing implied beyond it. Pulling…
split one vial across VendorInvestigate and PeptideMeter — 97.2% and 96.8%. One vial, one service, one member paying, which is the only kind of result this board should…
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…
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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