Page 3 of 20 · 466 questions tagged hplc.
Concretely: semaglutide · a C4 column · liraglutide. These are treated as interchangeable and I do not think they are. If both are acceptable I would like to know…
The specifics, since they change the answer: deamidation · ecnoglutide · 40 °C. I would like the mechanism, because I want to be able to reason about the cases nobody…
Conditions: 98.8% · a C4 column · dulaglutide. I would like to know the limits of what can be inferred from this. What I am trying to avoid is over-reading a single…
What I am working with: retatrutide · a C18 column · cagrilintide. I suspect the honest answer is that it depends, in which case I would like to know on what. Assume…
Setup, so nobody has to ask: a formic acid mobile phase · cagrilintide · a wide-pore C18 column. The empirical answer seems settled. The explanation does not. If the…
I sent two vials from two different batches, both labelled 10 mg semaglutide, for independent testing and asked for purity and quantification on each. The results…
Details up front: Medutest · 98.4%. Before I write this off, I want to check whether it is a known failure mode. I have the lot number, the certificate and the date,…
What I am working with: dimerisation · a GLP-1 receptor agonist · 2–8 °C. The empirical answer seems settled. The explanation does not. If the honest answer is that…
The specifics, since they change the answer: VendorInvestigate · 95.2%. Something has gone wrong and I would like to know how badly before I decide what to do.…
Conditions: 97.6% · date of analysis. I would like to know the limits of what can be inferred from this. What I am trying to avoid is over-reading a single result,…
What I have: 97.1% · retatrutide. This should be a straightforward calculation and I keep getting two different answers. The numbers are arbitrary; the method is what…
Conditions: ecnoglutide · 99.1%. 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…
The particulars: 99.1% · chromatogram. I want to understand what this actually establishes, as opposed to what it is being used to imply. My concern is that I am…
Details up front: a GLP-1 receptor agonist · Janoshik. I can parse the result. I am less sure what it licenses me to conclude. I have deliberately not looked at…
Details up front: 96.8% · a C8 column · liraglutide. This is presented as though it settles something, and I am not convinced it does. I have two documents that…
What I am working with: dimerisation · a GLP-1 receptor agonist · 37 °C. The empirical answer seems settled. The explanation does not. If the honest answer is that…
For reference: fibrillation · 30 °C. I understand the observation; what I do not understand is the mechanism behind it. I have read the two review articles that come…
What I have: hydrolysis · 40 °C. I can predict the outcome but I cannot explain it, which means I will get the next case wrong. I would like to know how confident the…
I have the report as a PDF with the chromatogram on page two, so I can quote specifics. This is presented as though it settles something, and I am not convinced it…
This is my second independent submission on material from the same supplier. I can find plenty of assertions about this and almost no reasoning, which is usually a…
Setup, so nobody has to ask: 96.8% · mazdutide. I have worked this out and I would like someone to find the error, because I suspect there is one. My working so far,…
The method section is present, which is unusual enough that I want to make use of it. The figures are clear enough; the question is what they mean and what they do…
Concretely: 96.8% · a C4 column · dulaglutide. I would like to know the limits of what can be inferred from this. What I am trying to avoid is over-reading a single…
Concretely: oxidation · 37 °C. This is one of those things that everyone repeats and nobody derives. This matters practically, not just academically, because it…