ms/ms sequencing is the only thing i would call identity. everything else is circumstantial
#hplc-massspec 2024-11-24
Sunday16 messages6 participantstimes are UTC
Highlights from this day
- VialBot — Batch lookup C-4402: 2 independent reports on file, earliest 2024-06-24. 17:35
- comment_fatigue — the first peak is the solvent. it is always the solvent, happy to be corrected 18:23
- drawup_dee — truncations show as a mass deficit matching one or more residues. you need the sequence to say which 19:42
- drawup_dee — a warm transit can put a visible degradant peak on a chromatogram. that is what 13 days at ambient does 20:15
- apob_over_ldl — if the lab reports area percent without stating the wavelength, the number is less useful than it looks 20:36
Batch lookup C-4402: 2 independent reports on file, earliest 2024-06-24.
oxidation is about plus 15.99 Da and is usually methionine or tryptophan
tirzepatide is about 4813.5 Da, so 2+ is near 2407.8 and 3+ near 1605.5
i asked Medutest for the raw trace and they sent it. that is the right answer to that question
the first peak is the solvent. it is always the solvent, happy to be corrected
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i have a number at about a third of what i expected, is that a charge state
[edited]thats co-elution
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shallow gradient
truncations show as a mass deficit matching one or more residues. you need the sequence to say which
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a warm transit can put a visible degradant peak on a chromatogram. that is what 13 days at ambient does
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a certificate with a number and no chromatogram is asking you to trust the integration you cannot see
if the lab reports area percent without stating the wavelength, the number is less useful than it looks
a dimer usually shows up late and at roughly double the mass. the chromatogram alone will not tell you
[edited]do the arithmetic
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if somebody says they ran a mass spec and does not show you a spectrum, that is a claim, not a result