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

[Question] how do you actually verify LC-MS

Questionbranch of 6 comments

Right, the integration question again, but with numbers this time. I have 13 data points over 6 weeks. The pattern is consistent enough that I do not think it is chance, and boring enough that nobody is going to screenshot it, which is usually a good sign. The thing I would flag for anyone new: the effect I am…

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6 comments, started 2 years ago
u/clara_danquah48 points·2 years ago

Yeah, the chromatogram profile matters more than the headline number.

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u/rasmus_petrescu21 points·2 years ago

co-elution is real and purity is usually not enough to resolve it

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u/step_count_stan11 points·2 years ago

integration decision on a shoulder changes your number by half a point on its own

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u/santiago_villalobos5 points·2 years ago

No. This is the kind of confident post that gets copied into a screenshot and repeated for years. Where is the evidence.

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u/sofia_petrescuOP4 points·2 years ago

The related substances profile is way more interesting than the main peak %. A 98% with 8 peaks is different from a 98% that is one 33% impurity.

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u/hamza_weiss5 points·2 years ago

integration decision on a shoulder changes your number by half a point on its own

Adding to this: integration is doing more work than the comment implies.

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