Page 21 of 21 · 503 questions tagged hplc.
Setup, so nobody has to ask: an HPLC purity test · dulaglutide. I would rather over-plan the first cycle and simplify later. I am prepared to do the work if someone…
Numbers first: 99.1% · lot-specific certificate. This is presented as though it settles something, and I am not convinced it does. I have two documents that appear to…
What I have: Medutest · 97.6%. 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, and I…
Numbers first: hydrolysis · 37 °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 particulars: oral semaglutide · a wide-pore C18 column · liraglutide. I am trying to choose between two options that are usually discussed as though only one…
The particulars: 99.4% · ecnoglutide. I would rather understand the derivation than memorise the outcome. Two people I asked gave two answers that differ by a factor…
What I have: cagrilintide · a C8 column · mazdutide. I have used one of these for a while and I am considering switching, which requires a reason. What I care about…
The specifics, since they change the answer: tirzepatide · a wide-pore C18 column · cagrilintide. The comparison I want does not seem to exist anywhere in a form I…
Setup, so nobody has to ask: 96.8% · a C18 column · semaglutide. I would like help reading this properly rather than being told what conclusion to reach. I have 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…
Details up front: a TFA mobile phase · dulaglutide · a C4 column. I suspect the usual explanation for this is wrong, or at least incomplete. I am aware this may have…
Details up front: mazdutide · 96.8%. This should be a straightforward calculation and I keep getting two different answers. The numbers are arbitrary; the method is…
Stated plainly: 96.8% · a C18 column · survodutide. I have read the primary source rather than the summary, which has left me with more questions. I understand the…
Concretely: 97.1% · liraglutide. 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…
Setup, so nobody has to ask: dulaglutide · a C18 column · tirzepatide. I suspect the honest answer is that it depends, in which case I would like to know on what.…
The case in front of me: retatrutide · Medutest. I have read the primary source rather than the summary, which has left me with more questions. I understand the…
The case in front of me: aspartimide formation · minus 80 °C. I want to know whether this is a real physical effect or an artefact of how it is measured. What…
The case in front of me: survodutide · a C4 column · tirzepatide. These are treated as interchangeable and I do not think they are. If both are acceptable I would…
Stated plainly: 99.4% · batch certificate. I have read the primary source rather than the summary, which has left me with more questions. I understand the headline. I…
Setup, so nobody has to ask: Janoshik · 97.1%. I noticed this today and I have not touched anything since, in case the state is diagnostic. I have not discarded…
Concretely: oxidation · oral semaglutide · 30 °C. This is one of those things that everyone repeats and nobody derives. This matters practically, not just…
What I am working with: 98.4% · 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…
Setup, so nobody has to ask: a formic acid mobile phase · mazdutide · a wide-pore C18 column. The empirical answer seems settled. The explanation does not. If the…