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c/hplc·posted 2 years ago by u/fatima_yildiz

why does nobody talk about method development

Lab

Been lurking in c/t2dglp1 for about 4 months and finally have something worth posting.

Short version: week 60, 2.5mg, and method development is the bit I still cannot get a straight answer on. I have read the wiki, I have read the last 37 threads, and the answers split roughly down the middle.

What I actually want to know is whether the people saying it does not matter have measured it, or whether it is just repeated confidently. Happy to be told I am overthinking this — I probably am — but I would rather overthink it now than at week 66.

457 up / 507 down47% upvoted13 commentsid 1qipcx27 Nov 2023

13 comments

13 in this archive, depth 5

best — the order this archive was captured in

u/gustav_solberg11 points·2 years ago·edited

This is the "correlation is mechanism" thing again. You changed three variables at once.

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u/mass_spec_maggieMOD6 points·2 years ago

Retitled to remove editorialising. Put the evidence in the body.

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u/adaeze_batista5 points·2 years ago·edited

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

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u/mariam_cabrera2 points·2 years ago

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

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u/matias_salgado2 points·2 years ago·edited

chromatogram or it did not happen

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u/rina_bergstrom1 point·2 years ago·edited

This is the correct method framing. Column and gradient are load-bearing fields.

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u/hana_lehtinen4 points·2 years ago·edited

Dead space in the needle hub holds a small but non-trivial volume. On low-volume draws that can be several units.

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u/chain_confirm_cpayments0 points·2 years ago

axis labels included, always

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[removed]1 point·2 years ago

[removed by moderator]

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u/phase_two_pete2 points·2 years ago

chromatogram or it did not happen

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u/egfr_watcher-11 points·2 years ago

chromatogram or it did not happen

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

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u/hedda_ekstrom0 points·2 years ago

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

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u/marit_mensa1 point·2 years ago

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

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About c/hplc

The analytical deep end: RP-HPLC methods, gradient design, integration decisions, LC-MS confirmation, amino-acid analysis, water content, and why two labs can report 98.1% and 96.4% on the same vial and both be right. Post the chromatogram, not the summary line.

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