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

what would you tell week-1 you about gradient

Discussionbranch of 12 comments

Been lurking in c/t2dglp1 for about 11 months and finally have something worth posting. Short version: week 76, 15mg, and method development is the bit I still cannot get a straight answer on. I have read the wiki, I have read the last 15 threads, and the answers split roughly down the middle. What I actually want to…

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12 comments, started 1 year ago
u/endotoxin_elliemicro626 points·1 year ago

axis labels included, always

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u/egfr_watcher162 points·1 year ago·edited

Respectfully this is a sample of one presented as a finding.

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[removed]233 points·1 year ago

[removed by moderator]

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u/first_hundred138 points·1 year ago

chromatogram or it did not happen

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u/marit_mwangiOP53 points·1 year 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 30% impurity.

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u/clara_danquah56 points·1 year ago·edited

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

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u/ewan_marchand290 points·1 year 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/marit_mwangiOP221 points·1 year ago

Gradient goblin mode: changed the solvent composition 14 times, finally got good resolution on a gradient peak.

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u/sofia_petrescu126 points·1 year ago

related substances are where the story lives, not the main peak

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u/vikram_asante39 points·1 year ago

related substances are where the story lives, not the main peak

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

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u/aksel_kjaer86 points·1 year ago

That is net peptide content, not purity. Different number, different meaning.

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u/yara_bakken29 points·1 year ago

chromatogram or it did not happen

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