Page 18 of 21 · 503 questions tagged hplc.
The case in front of me: survodutide · a C4 column · mazdutide. These are treated as interchangeable and I do not think they are. If both are acceptable I would like…
The case in front of me: aspartimide formation · tirzepatide · 25 °C. I want to know whether this is a real physical effect or an artefact of how it is measured. What…
What I am working with: 98.4% · cagrilintide. The units are where I keep going wrong, so please be explicit about them. I have sanity-checked the order of magnitude…
What I am working with: hydrolysis · room temperature. I can predict the outcome but I cannot explain it, which means I will get the next case wrong. I would like to…
Concretely: aspartimide formation · 2–8 °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…
Concretely: aspartimide formation · minus 20 °C. I want to know whether this is a real physical effect or an artefact of how it is measured. What prompted the…
Concretely: semaglutide · a C4 column · cagrilintide. I would like the axes of comparison first and the recommendation second. I have tried the first option and it…
Numbers first: 97.1% · a C8 column · tirzepatide. This is presented as though it settles something, and I am not convinced it does. I have two documents that appear…
The method section is present, which is unusual enough that I want to make use of it. I want the working, not the result — I need to be able to redo it with different…
The case in front of me: PeptideMeter · 99.4%. I have two candidate explanations and no way to distinguish them. The same procedure has worked without incident…
What I have: CPC · an HPLC purity test. 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…
Numbers first: racemisation · retatrutide · 40 °C. I suspect the usual explanation for this is wrong, or at least incomplete. I am aware this may have a boring…
For reference: 99.1% · survodutide. I would rather understand the derivation than memorise the outcome. Two people I asked gave two answers that differ by a factor of…
Setup, so nobody has to ask: dimerisation · 25 °C. The empirical answer seems settled. The explanation does not. If the honest answer is that nobody knows, I would…
What I am working with: 98.4% · a C18 column · ecnoglutide. I would like help reading this properly rather than being told what conclusion to reach. I have the full…
Conditions: ecnoglutide · VendorInvestigate. The figures are clear enough; the question is what they mean and what they do not. I can supply the numbers if the…
For reference: aspartimide formation · tirzepatide · room temperature. I want to know whether this is a real physical effect or an artefact of how it is measured.…
What I am working with: 98.8% · a C18 column · ecnoglutide. I would like help reading this properly rather than being told what conclusion to reach. I have the full…
Stated plainly: Janoshik · 96.8%. This is not behaving the way I expected and I want to understand the discrepancy before I act on it. I have photographed the current…
The specifics, since they change the answer: deamidation · 37 °C. I would like the mechanism, because I want to be able to reason about the cases nobody has written…
Stated plainly: 98.2% · batch certificate. I have read the primary source rather than the summary, which has left me with more questions. I understand the headline. I…
Stated plainly: dimerisation · cagrilintide · minus 20 °C. The empirical answer seems settled. The explanation does not. If the honest answer is that nobody knows, I…
Setup, so nobody has to ask: 97.9% · sampling plan. I would like help reading this properly rather than being told what conclusion to reach. I have the full report…
Details up front: racemisation · 2–8 °C. I suspect the usual explanation for this is wrong, or at least incomplete. I am aware this may have a boring answer. I would…