does ms/ms actually prove identity or just make it very likely
Thread · #hplc-massspec · 2025-05-10
do you trust an area percent from a shallow
Spun off from a message in #hplc-massspec on 2025-05-10. 15 messages, 6 participants.
The message this came from
- half_life_hal — do you trust an area percent from a shallow gradient 19:59
tirzepatide is about 4813.5 Da, so 2+ is near 2407.8 and 3+ near 1605.5
truncations show as a mass deficit matching one or more residues. you need the sequence to say which
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ask for the trace
coming back after 26 months, what changed in how you read these
plus 16 is oxidation
how much sample does a lab actually need for identity as well as purity
if the number you are staring at is a third of what you expected, do the charge state arithmetic before you panic
deamidation is about plus 0.98 Da. it is not a rounding error, it is a degradant
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first_month_fiif the number you are staring at is a third of what you expected, do the charge state…
how would a truncation sequence show up
whats a normal gradient for a peptide this size
plus 16 is oxidation
co-elution is the failure mode that a beautiful single peak is most likely to be hiding
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thats co-elution
how do you spot a deletion in a sequence from mass alone