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c/hplc·submitted 20 days ago by u/cagrilintide_enthusiast

retention time shifted 0.4 min and nobody wants to talk about it

Methodbranch of 7 comments

Long-ish post, sorry. tl;dr at the bottom. I have been tracking method development against eGFR for 19 weeks because I could not find anyone who had. The correlation is weaker than I expected, which is itself mildly interesting given how confidently people link the two in here. Caveats up front: one person, one lab,…

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7 comments, started 20 days ago
u/coa_janitormod · c/coa170 points·20 days ago

two labs, two different baselines, two different purity numbers, both honest

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u/marit_mensa142 points·20 days ago

two labs, two different baselines, two different purity numbers, both honest

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

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u/zeynep_zielinski209 points·20 days ago

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

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u/step_count_stan103 points·19 days ago

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

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

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u/adaeze_batista138 points·20 days ago·edited

Gradient goblin mode: changed the solvent composition 23 times, finally got good resolution on a LC-MS peak.

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u/cagrilintide_enthusiastOP84 points·19 days ago

Gradient goblin mode: changed the solvent composition 23 times, finally got good resolution on a LC-MS peak.

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

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u/reverse_image_ron68 points·19 days ago

two labs, two different baselines, two different purity numbers, both honest

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