the LC-MS thing finally clicked for me and I want to write it down
Right, the HPLC question again, but with numbers this time.
I have 3 data points over 20 weeks. The pattern is consistent enough that I do not think it is chance, and boring enough that nobody is going to screenshot it, which is usually a good sign.
The thing I would flag for anyone new: the effect I am describing showed up at week 62, not week 16. People give up long before the interesting part.
Interested in whether this matches other people's logs or whether I am an outlier.
best — the order this archive was captured in
Yeah, the chromatogram profile matters more than the headline number.
Removed a chain here. The rule is one line long and it is not negotiable.
Edit to your parent would help — the concentration you quoted assumes one scenario and you have written another above it.
instrument quality is less important than analyst consistency
Rodent data is rodent data. Dose scaling is not linear and the models tell you what to investigate, not what to expect.
The practical rule people converge on is 28 days at fridge temperature after first puncture, and that comes from the preservative, not the peptide.
Detection wavelength? HPLC and that changes at different wavelengths.
Strongly agree. Largest single impurity tells a different story than total purity.