coming back after 3 months, what changed in how you read these
#hplc-massspec 2025-04-19
Saturday14 messages4 participantstimes are UTC
Highlights from this day
- ten_of_ten — coming back to this baseline drift on a gradient is normal. baseline drift on an isocratic hold is your column 19:36
- ten_of_ten — why does integration change the number so much 19:50
- acetate_ash — the first peak is the solvent. it is always the solvent 20:04
- ten_of_ten — does retention time on its own tell you what the compound is 20:07
- void_volume — retention time is a hint, not a fingerprint. two different peptides can co-elute perfectly happily 20:11
is uv at 214 or 280 better for peptides
relative retention time against a standard is comparable between labs. absolute minutes are not
ask for the trace
coming back to this baseline drift on a gradient is normal. baseline drift on an isocratic hold is your column
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why does integration change the number so much
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semaglutide is about 4113.6 Da. [M+2H]2+ lands near 2057.8, [M+3H]3+ near 1372.2
the first peak is the solvent. it is always the solvent
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shallow gradients hide related substances behind the main peak. a steeper one separates and looks worse, honestly
does retention time on its own tell you what the compound is
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how do you tell co-elution from a clean single peak
is monoisotopic or average mass the one on most certificates
retention time is a hint, not a fingerprint. two different peptides can co-elute perfectly happily
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integration difference