shallow gradient
Thread · #hplc-massspec · 2026-03-12
my peak has a shoulder on it, what does
Spun off from a message in #hplc-massspec on 2026-03-12. 17 messages, 4 participants.
The message this came from
- zoya_zeros — my peak has a shoulder on it, what does that usually mean 22:10
is a tailing factor of anything specific a problem
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ms/ms sequencing is the only thing i would call identity. everything else is circumstantial
does retention time on its own tell you what the compound is
can you tell a dimer from the chromatogram alone
has anyone ever had a result where the mass was right and the purity was wrong
tirzepatide is about 4813.5 Da, so 2+ is near 2407.8 and 3+ near 1605.5
deamidation is about plus 0.98 Da. it is not a rounding error, it is a degradant
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how much sample does a lab actually need for identity as well as purity
i have had a lot where the mass was exactly right and the purity was 96.8. wrong question, right answer
run a blank
thats co-elution
how would a truncation sequence show up
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need more sample
monoisotopic and average diverge more the bigger the molecule. say which one you are quoting
oxidation is about plus 15.99 Da and is usually methionine or tryptophan
integration difference