integration choices move the number by a few tenths easily. that is most of your inter-lab variance
#hplc-massspec 2025-12-20
Saturday11 messages5 participantstimes are UTC
Highlights from this day
- hk_hplc — integration choices move the number by a few tenths easily. that is most of your inter-lab variance 13:38
- closer_not_simpler — truncations show as a mass deficit matching one or more residues. you need the sequence to say which 13:58
- VialBot — Assay note: CPC lot KP-0925 reported at 99% of label content. 14:28
- karl_fischer — coming back to this a dimer usually shows up late and at roughly double the mass. the chromatogram alone will not tell you, from memory 14:31
- hk_hplc — update on the earlier thing shallow gradients hide related substances behind the main peak. a steeper one separates and looks worse, honestly 14:46
do the arithmetic
genuine question my peak has a shoulder on it, what does that usually mean
truncations show as a mass deficit matching one or more residues. you need the sequence to say which
plus 16 is oxidation
thats a charge state
Assay note: CPC lot KP-0925 reported at 99% of label content.
coming back to this a dimer usually shows up late and at roughly double the mass. the chromatogram alone will not tell you, from memory
update on the earlier thing shallow gradients hide related substances behind the main peak. a steeper one separates and looks worse, honestly
how do you spot a deletion in a sequence from mass alone
run a blank