World of Peptideshttps://worldofpeptides.eu/Technical notes on quality control for research peptides: chromatograms, mass spectra, certificates of analysis and batch traceability.en Why 99% HPLC purity is not 99% peptide in the vialhttps://worldofpeptides.eu/read/why-99-percent-purity-is-not-99-percent-peptide.htmlhttps://worldofpeptides.eu/read/why-99-percent-purity-is-not-99-percent-peptide.htmlSat, 03 Oct 2026 07:04:00 +0100TFA and acetate counter-ions, residual water and the gap between HPLC purity and net peptide content, with a simple calculation on molar masses. What a certificate of analysis contains for a peptide batchhttps://worldofpeptides.eu/read/what-a-certificate-of-analysis-contains.htmlhttps://worldofpeptides.eu/read/what-a-certificate-of-analysis-contains.htmlFri, 02 Oct 2026 07:04:00 +0100The lines we look for on a peptide CoA: batch, method, HPLC purity, confirmed mass, appearance, date. And the signs that the document is a generic one. How we read an HPLC chromatogram of a peptidehttps://worldofpeptides.eu/read/how-we-read-an-hplc-chromatogram.htmlhttps://worldofpeptides.eu/read/how-we-read-an-hplc-chromatogram.htmlThu, 01 Oct 2026 07:04:00 +0100The 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.