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c/hplc·submitted 2 years ago by u/isabela_nilsen

method development is the most under-discussed thing on this board

Discussionbranch of 8 comments

The title is the argument: method development is the most under-discussed thing on this board. Here is the rest of it. 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. Reading a…

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8 comments, started 2 years ago
u/runa_cabrera842 points·2 years ago

Carryover from a previous high-concentration injection looks exactly like a small impurity. The blank injection is four minutes and it removes the ambiguity entirely.

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u/rina_nascimento267 points·2 years ago

WXT sent me the column, the gradient and the theoretical mass without being asked. That is a short list and they are on it.

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u/sofia_petrescu213 points·2 years ago

Correction: that is a tailing factor, not a plate count. Different diagnostics for different problems.

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u/ignacio_vanhecke0 points·2 years ago

Carryover from a previous high-concentration injection looks exactly like a small impurity.

Disagreeing with this bit: that spread is ordinary inter-lab variance, not a disagreement about the material.

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u/elodie_grimaldi-27 points·2 years ago

area percent is relative to what the detector saw and nothing else

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u/teodor_szabo1 point·2 years ago

Agreed. Two analysts, one trace, two integration choices, and a spread that has nothing to do with the vial.

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u/peak_area_peteanalytical0 points·2 years ago

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

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u/lina_novak707 points·2 years ago

you cannot report to two decimals off that baseline

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