unrelated but retention time is a hint, not a

shallow gradients hide related substances behind the main peak. a steeper one separates and looks worse, honestly

whats a plus one dalton shift usually

run a blank

is uv at 214 or 280 better for peptides

is monoisotopic or average mass the one on most certificates

214nm sees the amide backbone so it sees everything. 280 only sees aromatics

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

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

a dimer usually shows up late and at roughly double the mass. the chromatogram alone will not tell you

run a blank