Research question
What does HPLC purity of at least 99 percent mean?
HPLC purity is a chromatographic result. The instrument separates components and the software reports the area of the main peak against the areas it detected. When GetReta says a lot is at least 99 percent, the release record for that lot met that bar. The certificate shows the figure for the lot on your label, which can sit above 99 percent. The sample row uses 99.2 percent only as a demonstration.
The number does not say the vial is sterile in the sense of a finished medicine, and it does not say the peptide will behave a certain way in an assay you have not run. It also does not survive unchanged if the solid is stored badly or dissolved in a solvent your method does not control. Quote the certificate, not a rounded slogan, when you write up the lot.
If you need the chromatogram explained, email the lot code to orders@getreta.co.uk. GetReta will not convert the percentage into a dose. Research use only.