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c/hplc·submitted 17 days ago by u/ignacio_vanhecke

[Lab] LC-MS confirmed identity but the UV purity is 94%. now what

Labbranch of 5 comments

Genuinely asking, not being difficult. Everyone in c/glp1eu repeats that gradient is important. I believe it, but I have never seen anyone show why, and when I search I get 18 threads of people agreeing with each other. Is there a paper? Is there a measurement? Or is this one of those things that is true because it…

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5 comments, started 17 days ago
u/rina_bergstrom276 points·17 days ago

Strongly agree. Largest single impurity tells a different story than total purity.

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u/dilara_nyberg-22 points·16 days ago

The related substances profile is way more interesting than the main peak %. A 98% with 5 peaks is different from a 98% that is one 36% impurity.

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u/rasmus_kimani1 point·16 days ago

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

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u/arne_nyberg97 points·16 days ago

Did they post the raw trace or just the summary?

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[removed]71 points·16 days ago

[removed by moderator]

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