Page 8 of 20 · 466 questions tagged hplc.
Concretely: semaglutide · 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…
Setup, so nobody has to ask: retatrutide · a C18 column · survodutide. Both of these get recommended confidently by different people, which suggests neither is…
The case in front of me: aspartimide formation · room temperature. I want to know whether this is a real physical effect or an artefact of how it is measured. What…
Details up front: racemisation · retatrutide · 2–8 °C. I suspect the usual explanation for this is wrong, or at least incomplete. I am aware this may have a boring…
What I am working with: a formic acid mobile phase · a GLP-1 receptor agonist · a wide-pore C18 column. I keep seeing this stated as a fact with no explanation…
Stated plainly: 95.2% · a C18 column · survodutide. I have read the primary source rather than the summary, which has left me with more questions. I understand the…
What I have: 99.1% · retatrutide. 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…
For reference: 96.8% · semaglutide. I would rather understand the derivation than memorise the outcome. Two people I asked gave two answers that differ by a factor of…
Stated plainly: aggregation · a GLP-1 receptor agonist · minus 80 °C. I keep seeing this stated as a fact with no explanation attached, and unexplained facts make me…
Conditions: oxidation · minus 20 °C. This is one of those things that everyone repeats and nobody derives. This matters practically, not just academically, because it…
Setup, so nobody has to ask: dulaglutide · Medutest. I have read the primary source rather than the summary, which has left me with more questions. I understand the…
The method section is present, which is unusual enough that I want to make use of it. I would like to know the limits of what can be inferred from this. What I am…
Conditions: 98.2% · method section. The figures are clear enough; the question is what they mean and what they do not. I can supply the numbers if the specifics…
Conditions: PeptideMeter · 98.4%. 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 method section is present, which is unusual enough that I want to make use of it. I want to know whether this is a real physical effect or an artefact of how it…
The particulars: fibrillation · ecnoglutide · 2–8 °C. I understand the observation; what I do not understand is the mechanism behind it. I have read the two review…
Details up front: mazdutide · Janoshik. 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: 97.1% · orforglipron. This should be a straightforward calculation and I keep getting two different answers. The numbers are arbitrary; the method is…
Conditions: 97.1% · method section. The figures are clear enough; the question is what they mean and what they do not. I can supply the numbers if the specifics…
The particulars: oral semaglutide · a wide-pore C18 column · tirzepatide. The comparison I want does not seem to exist anywhere in a form I can evaluate. I have read…
The case in front of me: 98.2% · 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…
A report I have includes traces at two wavelengths from the same injection, using a diode-array detector. The 214 nm trace integrates to 98.6% and the 280 nm trace to…
The vial was lyophilised at the time, which I understand may matter a great deal. I keep seeing this stated as a fact with no explanation attached, and unexplained…
Conditions: PeptideMeter · 97.1%. 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…