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

3 months in and chromatogram is still the thing I get wrong

Methodbranch of 7 comments

Trying to settle this properly because the thread from last year went in circles. The claim: HPLC matters. The counter-claim: it is measurement error. Both sides have been asserting it confidently for about 15 months without either producing anything. What would actually settle it is 11 people measuring the same…

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7 comments, started 1 year ago
u/runa_cabrera-32 points·1 year ago

A shoulder on the main peak that 13 analysts integrated 16 different ways. Same trace, 97.9 spread.

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u/ravi_bergstromOP1 point·1 year ago

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

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u/ewan_tulloch1 point·1 year ago

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

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u/hana_lehtinen1 point·1 year ago

Strongly agree. Largest single impurity tells a different story than total purity.

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u/yara_bakken1 point·1 year ago

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

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u/aksel_palacios1 point·1 year ago

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

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u/sofia_petrescu1 point·1 year ago

axis labels included, always

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