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#hplc-massspec 2025-06-16

Monday11 messages4 participantstimes are UTC
Highlights from this day
  • eight_mm — is monoisotopic or average mass the one on most certificates 14:24
  • salt_bridge — a certificate with a number and no chromatogram is asking you to trust the integration you cannot see 14:26
  • salt_bridge — the first peak is the solvent. it is always the solvent, anyway 14:32
  • HPLC_Hank — how do you spot a deletion in a sequence from mass alone retention time is a hint, not a fingerprint. two different peptides can co-elute perfectly happily 15:17
  • panel_before_after — truncations show as a mass deficit matching one or more residues. you need the sequence to say which 15:57
EM

is monoisotopic or average mass the one on most certificates

[edited]
SB

a certificate with a number and no chromatogram is asking you to trust the integration you cannot see

within inter-lab range

shallow gradient

the first peak is the solvent. it is always the solvent, anyway

retention time is a hint

HH

how do you spot a deletion in a sequence from mass alone
retention time is a hint, not a fingerprint. two different peptides can co-elute perfectly happily

M      = 4113.6
[M+2H]2+ = (4113.6 + 2.02) / 2 = 2057.8
[M+3H]3+ = (4113.6 + 3.02) / 3 = 1372.2
observed 1372.3 -> consistent

truncations show as a mass deficit matching one or more residues. you need the sequence to say which