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c/hplc·submitted 11 months ago by u/week_four_wall

[Meta] proposal — a flair for LC-MS posts

Labbranch of 7 comments

proposal — a flair for LC-MS posts. Short post, long comment section, probably. QYB sent me the column, the gradient and the theoretical mass without being asked. That is a short list and they are on it. Started reporting my own integrations with the baseline choice stated. Arguments in my threads dropped by about…

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7 comments, started 10 months ago
u/first_hundred409 points·10 months ago

Area percent is the integrated area of your peak over the total integrated area at one wavelength on one gradient. Change any of those and the number changes without the sample changing.

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u/dilara_nyberg283 points·10 months ago

axis labels or the trace is decoration

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u/hydration_hank91 points·10 months ago

a shoulder is not an impurity until you can resolve it

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u/two_mil_or_one59 points·10 months ago

214nm sees the peptide bond, 280nm sees the aromatics

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u/sig_figs_sammod · analytical74 points·10 months ago

Disagree. Inter-lab spread of a point or two on this assay is ordinary and calling it a discrepancy misleads people.

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u/ewan_marchand119 points·10 months ago

UV response is not uniform across species. At 214nm you are looking at the peptide bond, which is why it is the working wavelength for this class; at 280nm you only see tryptophan, tyrosine and phenylalanine.

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