Page 15 of 21 · 503 questions tagged hplc.
I have both a purity figure and a content figure, which is why the discrepancy is visible. I am trying to choose between two options that are usually discussed as…
What I am working with: aggregation · 37 °C. I keep seeing this stated as a fact with no explanation attached, and unexplained facts make me suspicious. My background…
For reference: fibrillation · semaglutide · 37 °C. I understand the observation; what I do not understand is the mechanism behind it. I have read the two review…
Stated plainly: retatrutide · a C18 column · semaglutide. Both of these get recommended confidently by different people, which suggests neither is obviously right. My…
The case in front of me: 95.2% · a C4 column · orforglipron. The figures are clear enough; the question is what they mean and what they do not. I can supply the…
Setup, so nobody has to ask: 96.4% · a C18 column · survodutide. I would like help reading this properly rather than being told what conclusion to reach. I have the…
Setup, so nobody has to ask: 98.8% · a C18 column · semaglutide. I have read the primary source rather than the summary, which has left me with more questions. I…
The case in front of me: ecnoglutide · a C4 column · semaglutide. These are treated as interchangeable and I do not think they are. If both are acceptable I would…
What I have: 99.4% · orforglipron. This should be a straightforward calculation and I keep getting two different answers. The numbers are arbitrary; the method is…
The particulars: tirzepatide · a wide-pore C18 column · semaglutide. I am trying to choose between two options that are usually discussed as though only one exists. I…
For reference: tirzepatide · a wide-pore C18 column · survodutide. I am trying to choose between two options that are usually discussed as though only one exists. I…
Stated plainly: dimerisation · cagrilintide · 25 °C. The empirical answer seems settled. The explanation does not. If the honest answer is that nobody knows, I would…
Stated plainly: dimerisation · a GLP-1 receptor agonist · 25 °C. The empirical answer seems settled. The explanation does not. If the honest answer is that nobody…
Setup, so nobody has to ask: aggregation · cagrilintide · 37 °C. I keep seeing this stated as a fact with no explanation attached, and unexplained facts make me…
The lot number on the vial matches the certificate, which at least rules out the easy problem. The units are where I keep going wrong, so please be explicit about…
The particulars: 98.4% · a wide-pore C18 column · cagrilintide. I have the document in front of me and I can read the numbers. What I cannot do is interpret them. I…
The particulars: 96.8% · a wide-pore C18 column · cagrilintide. I have the document in front of me and I can read the numbers. What I cannot do is interpret them. I…
The particulars: VendorInvestigate · 98.4%. An unexpected observation, and I would like a differential rather than reassurance. The conditions were within what I…
The particulars: 97.6% · survodutide. I would like the arithmetic checked rather than the conclusion asserted. I have deliberately not used an online calculator…
The specifics, since they change the answer: VendorInvestigate · 99.4%. An unexpected observation, and I would like a differential rather than reassurance. The…
This is my second independent submission on material from the same supplier. I can parse the result. I am less sure what it licenses me to conclude. I have…
Details up front: hydrolysis · orforglipron · 4 °C. I can predict the outcome but I cannot explain it, which means I will get the next case wrong. I would like to…
The particulars: deamidation · survodutide · minus 80 °C. I would like the mechanism, because I want to be able to reason about the cases nobody has written about. I…
Details up front: racemisation · 40 °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…