#hplc-massspec 2026-05-17

oxidation is about plus 15.99 Da and is usually methionine or tryptophan

do you trust an area percent from a shallow gradient

how would a truncation sequence show up

does ms/ms actually prove identity or just make it very likely

within inter-lab range

show me the spectrum

for the archive whats a plus one dalton shift usually

how do you tell co-elution from a clean single peak

is uv at 214 or 280 better for peptides
a warm transit can put a visible degradant peak on a chromatogram. that is what 17 days at ambient does

is monoisotopic or average mass the one on most certificates

follow up if somebody says they ran a mass spec and does not show you a spectrum, that is a claim, not a result

i asked VendorInvestigate for the raw trace and they sent it. that is the right answer to that question

i have a number at about a third of what i expected, is that a charge state

my peak has a shoulder on it, what does that usually mean

you need more sample for identity than for purity. plan for that when you post it

*that should say weekly