theme / Analytical methods

Analytical methods

03.10.2026Analytical methods5 min

Why 99% HPLC purity is not 99% peptide in the vial

TFA and acetate counter-ions, residual water and the gap between HPLC purity and net peptide content, with a simple calculation on molar masses.

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01.10.2026Analytical methods

How we read an HPLC chromatogram of a peptide

The axes, the main peak, retention time, the small peaks beside it and how purity is worked out from peak areas. And what a chromatogram cannot tell us.