Positions 26–50 of 130.
batch is doing more work than we give it credit for. I have gone back and forth on this for months. The four things a certificate must carry, and what each one is for.…
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…
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…
Slightly embarrassed to be asking this, but: why does nobody talk about batch. Spent four months confusing area% and mass% in every post I made here. One explainer…
Reference standards, analytical reagents and system-suitability material. If you are running your own method, start with a known.
Reference standardshow 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…
Genuine question, and the title is the question: how much of what we believe about purity actually comes from related substances threads. Related substances itemised…
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…
related substances — what am I missing here — that is what I am asking, and I have already read the wiki twice. Ask what the stability statement was written against —…
genuine question about area percent 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…
Question in the title, detail here: can we stop arguing about related substances until somebody posts a number. Started keeping a folder of every certificate I have…
Posting this because the title is the whole finding — GGPeps vs GL Biochem on the same compound, same month — both cleared 99.0% — and a number without its method is a…
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…
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…
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…
area percent — 13 things I got wrong before I got it right — a position I have arrived at slowly and would like tested. LC-MS gives you identity; UV purity gives you a…
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.netwe are measuring certificate of analysis at the wrong time and calling it noise. Change my mind, genuinely — I have no stake in being right about this. Water content…
7th independent test on WXT — 99.2% on a claimed 98.5%, and the trend is the interesting part. That is the headline. The document, the batch and the service are below…
Genuine question, and the title is the question: can we stop arguing about COA until somebody posts a number. Spent four months confusing area% and mass% in every post…
Slightly 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…
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…
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 title is the whole question — someone explain COA to me like I have not read a paper in years — but here is why I am asking. The PDF creation date being later than…
Posting this because the title is the whole finding — KP vs BCH on the same compound, same month — both cleared 97.5% — and a number without its method is a rumour.…
The title is the whole question — how much of what we believe about area percent actually comes from COA threads — but here is why I am asking. Started keeping a folder…
does purity actually matter or is it forum lore at this point. Searched first, found three threads that contradict each other, hence the post. Asked QST for the…
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