Page 4 of 20 · 466 questions tagged hplc.
Stated plainly: Janoshik · 97.9%. I noticed this today and I have not touched anything since, in case the state is diagnostic. I have not discarded anything yet, so a…
Concretely: aspartimide formation · 30 °C. I want to know whether this is a real physical effect or an artefact of how it is measured. What prompted the question is…
The specifics, since they change the answer: 98.4% · semaglutide. I would like the arithmetic checked rather than the conclusion asserted. I have deliberately not…
The lot number on the vial matches the certificate, which at least rules out the easy problem. I would like to know the limits of what can be inferred from this. What…
The case in front of me: PeptideMeter · 96.4%. I have two candidate explanations and no way to distinguish them. The same procedure has worked without incident…
Stated plainly: 96.4% · cagrilintide. I have worked this out and I would like someone to find the error, because I suspect there is one. My working so far, for the…
Stated plainly: 98.2% · a GLP-1 receptor agonist. I have worked this out and I would like someone to find the error, because I suspect there is one. My working so…
Conditions: PeptideMeter · 96.8%. I have two candidate explanations and no way to distinguish them. The same procedure has worked without incident several times…
Concretely: PeptideMeter · 97.9%. I think I have a problem. I am not yet sure whether it is a real problem or a measurement artefact. I want to know whether this is…
Concretely: ecnoglutide · a C4 column · tirzepatide. These are treated as interchangeable and I do not think they are. If both are acceptable I would like to know…
Conditions: ecnoglutide · a C4 column · retatrutide. These are treated as interchangeable and I do not think they are. If both are acceptable I would like to know…
Conditions: 99.4% · oral semaglutide. Please show the division. I want to check my own against yours. I would like the general form as well as the specific number, so…
Details up front: 95.2% · dulaglutide. I can do the algebra. I am not confident about the conversion factors. If there is a standard way to lay this out, I would…
For reference: liraglutide · a wide-pore C18 column · tirzepatide. I am trying to choose between two options that are usually discussed as though only one exists. I…
Conditions: semaglutide · 97.1%. I want the working, not the result — I need to be able to redo it with different numbers. I care about the precision as well as the…
Stated plainly: 96.4% · a C18 column · ecnoglutide. I have read the primary source rather than the summary, which has left me with more questions. I understand the…
Stated plainly: 97.1% · cagrilintide. The units are where I keep going wrong, so please be explicit about them. I have sanity-checked the order of magnitude and it…
Details up front: racemisation · retatrutide · 4 °C. I suspect the usual explanation for this is wrong, or at least incomplete. I am aware this may have a boring…
Numbers first: 99.1% · orforglipron. I can do the algebra. I am not confident about the conversion factors. If there is a standard way to lay this out, I would rather…
The case in front of me: 99.1% · tirzepatide. I want the working, not the result — I need to be able to redo it with different numbers. I care about the precision as…
The particulars: 98.8% · semaglutide. I would like the arithmetic checked rather than the conclusion asserted. I have deliberately not used an online calculator…
Concretely: oxidation · 4 °C. This is one of those things that everyone repeats and nobody derives. This matters practically, not just academically, because it…
For reference: fibrillation · 37 °C. I understand the observation; what I do not understand is the mechanism behind it. I have read the two review articles that come…
Numbers first: 99.4% · a C8 column · liraglutide. This is presented as though it settles something, and I am not convinced it does. I have two documents that appear…