why does integration change the number so much
#hplc-massspec 2026-03-23
Monday15 messages4 participantstimes are UTC
Highlights from this day
- ghent_gradient — the first peak is the solvent. it is always the solvent 17:56
- deamidation — tirzepatide is about 4813.5 Da, so 2+ is near 2407.8 and 3+ near 1605.5 17:58
- two_four_ceiling — update on the earlier thing truncations show as a mass deficit matching one or more residues. you need the sequence to say which 19:06
does ms/ms actually prove identity or just make it very likely
the first peak is the solvent. it is always the solvent
peak RRT area% note
1 0.42 0.31 solvent front
2 0.88 0.44 related substance
3 1.00 98.72 main
4 1.14 0.53 related substancemy peak has a shoulder on it, what does that usually mean
tirzepatide is about 4813.5 Da, so 2+ is near 2407.8 and 3+ near 1605.5
😂1📈2🙏1
does retention time on its own tell you what the compound is
coming back after 2 months, what changed in how you read these
update on the earlier thing ms/ms sequencing is the only thing i would call identity. everything else is circumstantial, thats just me
you need more sample for identity than for purity. plan for that when you post it
has anyone ever had a result where the mass was right and the purity was wrong
a warm transit can put a visible degradant peak on a chromatogram. that is what 26 days at ambient does, i think
integration choices move the number by a few tenths easily. that is most of your inter-lab variance
need more sample
is monoisotopic or average mass the one on most certificates
update on the earlier thing truncations show as a mass deficit matching one or more residues. you need the sequence to say which
🧪1