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c/hplc·submitted 2 years ago by u/amara_haddad

[Question] Ireland — has anyone got a straight answer on chromatogram

Questionbranch of 9 comments

Week 58 update. 34kg down from the start, reflux basically gone since about week 3. Things that worked: consistency, protein at breakfast, walking more than I want to. Things that did not: everything I bought on the internet to help with reflux. The part that surprised me is how much of this is admin. Ordering,…

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9 comments, started 2 years ago
u/week_four_wall415 points·2 years ago

chromatogram or it did not happen

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u/honest_syringe_2025194 points·2 years ago

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

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u/runa_cabrera106 points·2 years ago

Water content matters more than people think. If a vial is carrying residual moisture, your "10mg" is not 10mg of peptide.

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u/amara_haddadOP54 points·2 years ago

A shoulder on the main peak that 9 analysts integrated 24 different ways. Same trace, 97.6 spread.

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u/phase_two_pete29 points·2 years ago

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

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u/amara_haddad18 points·2 years ago

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

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u/hazard_ratio_halstats29 points·2 years ago

A shoulder on the main peak that 9 analysts integrated 24 different ways.

Disagree on that part. 95.1% and 98.9% on the same vial is normal.

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u/aksel_kjaer37 points·2 years ago

instrument quality is less important than analyst consistency

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u/elodie_grimaldi12 points·2 years ago

instrument quality is less important than analyst consistency

Yes, exactly this, and it is the bit that took me 39 weeks to accept.

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