Positions 51–75 of 130.
Genuine question, and the title is the question: genuine question about chromatogram that I am slightly embarrassed to ask. Sent the same vial to PeptideMeter and…
proposal — a flair for HPLC posts. This affects how posts get sorted and removed, so it belongs in the open. Chased a ghost peak for three weeks. It was the plumbing.…
Asking properly rather than in a comment on somebody else’s thread: how do you actually verify method development. The system suitability argument, since it comes up…
is 96.8% actually fine or am I being sold a rounding error, and before anyone asks: same batch throughout, single submission, no cherry-picking between services. 96.8%…
Reference standards, analytical reagents and system-suitability material. If you are running your own method, start with a known.
Reference standardsThe title is the whole question — help me understand LC-MS, I have read the wiki twice — but here is why I am asking. Area percent is the integrated area of your peak…
the gradient rule is doing its job and people should stop complaining. Nothing about this affects the ranking maths, before anyone asks. Reading a trace posted here, in…
Asking properly rather than in a comment on somebody else’s thread: gradient — what am I missing here. A shoulder that does not baseline-resolve cannot be quantified…
proposal — a flair for chromatogram posts — with the counter-argument included, because I find it fairly persuasive. Resolution between two peaks depends on retention,…
The title is the argument: we are measuring LC-MS at the wrong time and calling it noise. Here is the rest of it. SWB sent me the column, the gradient and the…
Right: MKM cagri — Medutest came back 97.7% against a claimed 97.0%. I paid for this one myself, nobody sent me anything, and the receipts are in the comments. The…
gradient is the most under-discussed thing on this board. Not a hot take, just something I have not seen said plainly here. Resolution between two peaks depends on…
The title is the argument: we are measuring HPLC at the wrong time and calling it noise. Here is the rest of it. Area percent is the integrated area of your peak over…
reading gradient threads from 2024 and half of it aged badly. It is the sort of thing everyone half-believes and nobody writes down. Resolution between two peaks…
three years of LC-MS threads, summarised so you do not have to read them — a position I have arrived at slowly and would like tested. A shoulder that does not…
how much of what we believe about integration actually comes from LC-MS threads. Searched first, found three threads that contradict each other, hence the post. Chased…
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.netTrying to get a straight answer on this: does gradient actually matter or is it forum lore at this point. A shoulder that does not baseline-resolve cannot be quantified…
LC-MS — what am I missing here — that is what I am asking, and I have already read the wiki twice. Bought a second-hand instrument and learned more in six months of…
the chromatogram advice in here is 2 years out of date — a position I have arrived at slowly and would like tested. Numbers, in the order they matter: 2 years.…
method development — 13 things I got wrong before I got it right. Not a hot take, just something I have not seen said plainly here. Ran a blank after a…
Genuine question, and the title is the question: how much of what we believe about HPLC actually comes from integration threads. Started reporting my own integrations…
proposal — a flair for LC-MS posts. Short post, long comment section, probably. QYB sent me the column, the gradient and the theoretical mass without being asked. That…
HJ cagri — Janoshik came back 97.5% against a claimed 97.0%, and before anyone asks: same batch throughout, single submission, no cherry-picking between services. The…
Putting this to the board: proposal — a flair for gradient posts. A shoulder that does not baseline-resolve cannot be quantified honestly. You can report it as an…
how much of what we believe about HPLC actually comes from LC-MS threads. Searched first, found three threads that contradict each other, hence the post. Chased a ghost…
reading purity threads from 2024 and half of it aged badly — a position I have arrived at slowly and would like tested. A shoulder that does not baseline-resolve cannot…
The analytical deep end: RP-HPLC methods, gradient design, integration decisions, LC-MS confirmation, amino-acid analysis, water content, and why two labs can report 98.1% and 96.4% on the same vial and both be right. Post the chromatogram, not the summary line.
Independent testing plus vendor-level trend data. Community-funded, unaffiliated.
peptidemeter.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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