Page 10 of 21 · 503 questions tagged hplc.
Details up front: racemisation · a C8 column. I suspect the usual explanation for this is wrong, or at least incomplete. I am aware this may have a boring answer. I…
Details up front: racemisation · dulaglutide · minus 20 °C. I suspect the usual explanation for this is wrong, or at least incomplete. I am aware this may have a…
The specifics, since they change the answer: 95.2% · ecnoglutide. I would like the arithmetic checked rather than the conclusion asserted. I have deliberately not…
Concretely: oxidation · 2–8 °C. This is one of those things that everyone repeats and nobody derives. This matters practically, not just academically, because it…
Conditions: 99.4% · a C4 column · orforglipron. 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: 95.2% · batch certificate. I have read the primary source rather than the summary, which has left me with more questions. I understand the…
What I am working with: Janoshik · 99.4%. I noticed this today and I have not touched anything since, in case the state is diagnostic. I have not discarded anything…
Concretely: oxidation · liraglutide · 25 °C. This is one of those things that everyone repeats and nobody derives. This matters practically, not just academically,…
Concretely: aspartimide formation · tirzepatide · 4 °C. I want to know whether this is a real physical effect or an artefact of how it is measured. What prompted the…
Conditions: 97.6% · tirzepatide. 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 I…
Concretely: 99.4% · 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 am working with: Janoshik · 98.8%. I noticed this today and I have not touched anything since, in case the state is diagnostic. I have not discarded anything…
The lot number on the vial matches the certificate, which at least rules out the easy problem. The figures are clear enough; the question is what they mean and what…
Setup, so nobody has to ask: dimerisation · mazdutide · 37 °C. The empirical answer seems settled. The explanation does not. If the honest answer is that nobody…
Details up front: hydrolysis · orforglipron · 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…
Details up front: 96.8% · orforglipron. This should be a straightforward calculation and I keep getting two different answers. The numbers are arbitrary; the method…
I am about to pay for quantification on a group of vials rather than just purity, having read enough here to understand why. Before I do, I want to know what I am…
The particulars: 97.1% · list of related substances. I have the document in front of me and I can read the numbers. What I cannot do is interpret them. I am…
The case in front of me: aspartimide formation · 25 °C. I want to know whether this is a real physical effect or an artefact of how it is measured. What prompted the…
I am trying to specify a method to a contract lab rather than accept their default, and I do not know enough to write a sensible specification. The choices I can see…
Concretely: PeptideMeter · 99.1%. 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…
The case in front of me: oxidation · minus 80 °C. This is one of those things that everyone repeats and nobody derives. This matters practically, not just…
What I have: racemisation · 37 °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 still…
For reference: VendorInvestigate · 96.8%. An unexpected observation, and I would like a differential rather than reassurance. The conditions were within what I…