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c/hplc·submitted 1 year ago by u/two_mil_or_one

tried HPLC for 5 weeks. here is what happened.

Labbranch of 5 comments

Something I noticed reading old threads that I have not seen said out loud. The advice on chromatogram in this community changed substantially around the start of last year, and nobody went back and updated the older posts. So depending on which thread the search engine hands you, you get two contradictory answers…

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5 comments, started 1 year ago
u/lina_novak441 points·1 year ago

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

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u/clara_danquah663 points·1 year ago·edited

area% and mass% are not the same and this whole post conflates them

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u/week_four_wall335 points·1 year ago

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

Disagree on that part. 97.9% and 97.6% on the same vial is normal.

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u/two_mil_or_oneOP-10 points·1 year ago

The related substances profile is way more interesting than the main peak %. A 98% with 11 peaks is different from a 98% that is one 23% impurity.

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u/georgi_tamm1 point·1 year ago

The related substances profile is way more interesting than the main peak %.

Counter-anecdote: opposite result, same dose. Which mostly tells us the variance is huge.

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