Topic summary
Coming back to: Where the integrator drew the baseline, and how much it moved the number
This is a generated summary. It shows the 5 most-liked posts from a topic of 25, in their original order, with the accepted answer included where one exists. It is a reading aid and it will miss nuance — the full topic is the record.
Post #7 is right about the mechanism and I think understates the practical bit.
A chromatogram image at a resolution where you can see peak shape but not baseline detail is worth having and is not the same as the data. Ask for the integration table if the number matters.
22 likes 10mo
n.moreau, post #2: Where I part company with the opening post, and it is a narrow parting. Where the baseline is drawn is the least documented and most consequential choice in the whole determination. Valley-to-valley, tangent skim and forced-to-zero can span a couple of percentage points on the same chromatogram. Adding a source would improve this post… Go to post
A relative retention time against a known peak travels much better than an absolute one, and almost nobody reports it.
The general case is well covered; this is the awkward specific one.
a.frisk, post #4: What I would check first on integrator is whether the thing being measured moved or whether the way of measuring it moved. Those look identical in a graph. Go to post
Adding a note of thanks rather than an opinion. I did not know most of that.
What I can speak to on integrator is narrow, so I will keep it narrow rather than generalising from it. Beyond that boundary I do not know.
20 likes 10mo
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This topic was referenced in
- Why 99.2% and 97.8% on the same lot can both be correctAnalytics › HPLC & UHPLC · 20 replies
Moved from COA interpretation by KLindqvist. Category placement is not obvious from outside and getting it wrong is expected. This topic will get better answers here. The move is recorded in the public log citing R7.
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