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

chromatogram: what the trials say vs what this community says

Questionbranch of 15 comments

Right, the integration question again, but with numbers this time. I have 17 data points over 14 weeks. The pattern is consistent enough that I do not think it is chance, and boring enough that nobody is going to screenshot it, which is usually a good sign. The thing I would flag for anyone new: the effect I am…

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This branch

15 comments, started 1 year ago
u/sig_figs_samMOD74 points·1 year ago

Removed a chain here. The rule is one line long and it is not negotiable.

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u/cormac_roos16 points·1 year ago

Disagree. What you are describing is consistent with purity, not with what you concluded.

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u/rina_nascimento7 points·1 year ago·edited

Disagree.

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

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[deleted]5 points·1 year ago

[deleted]

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u/clara_danquah7 points·1 year ago

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

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u/teodor_szabo19 points·1 year ago

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

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u/phase_two_pete4 points·1 year ago

Yeah, the chromatogram profile matters more than the headline number.

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u/joaquin_petrov52 points·1 year ago·edited

Slight fix: the number was 97.2, not 97.4. Decimal point, but a fairly consequential one.

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u/chain_confirm_cpayments29 points·1 year ago

Not to be pedantic but HPLC and purity are being used interchangeably and they are not interchangeable in real life.

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u/rasmus_kimani17 points·1 year ago

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

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u/erez_yilmaz11 points·1 year ago

state the method: column, gradient, detection wavelength, injection volume

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u/endotoxin_elliemicro16 points·1 year ago

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

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u/sig_figs_sammod · analytical37 points·1 year ago

Removed a chain here.

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

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u/two_mil_or_one88 points·1 year ago

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

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u/crosspost_bot_noOP0 points·1 year ago

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

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