water content, counterion, and the honest eleven point four milligrams

The certificate-reading channel had its most technical fortnight, prompted by a member who believed they had received overfilled vials and had in fact received a supplier that reports gross mass. Karl Fischer water content, counterion and net peptide got worked through properly, and the fortnight ended with the channel able to read a full certificate rather than one line of it.

• Net peptide content is gross mass minus water and minus counterion, which is why an honest ten milligram vial can weigh eleven point four.
• Water content by Karl Fischer was explained as the line most people skip and the one that reconciles the arithmetic.
• Residual solvents and the related-substances table were introduced as the parts of a certificate that reward attention.
• Shanghai Wibson and Chinese Peptide Company documents were compared as two different reporting conventions, neither wrong and neither interchangeable.
• A member withdrew an accusation of overfill and posted why they had been mistaken, which the channel considered exemplary.
• The pinned wording about net peptide dates from this fortnight and has needed no editing since.