How REVIVE LAB tests purity

Purity by HPLC

High-performance liquid chromatography separates the components of a sample by how strongly each interacts with a column packing as a solvent carries them through. Compounds emerge at different times, and a detector records each as a peak. The area of the target peak relative to the total area gives the chromatographic purity figure quoted on a Certificate of Analysis.

A purity figure is therefore a statement about a specific method: the column, the solvent gradient and the detection wavelength all shape it. This is why a COA states the method and not only the number.

Identity by mass spectrometry

HPLC shows that a sample is largely one thing. It does not, by itself, prove that the one thing is the intended sequence. Mass spectrometry measures the mass-to-charge ratio of the molecule, which is compared against the theoretical mass calculated from the sequence.

A mass that matches to within the instrument's tolerance confirms the molecular weight is right. Together with a clean chromatogram, that establishes both that the material is what it claims to be, and that there is little else present.

What analysis does not tell you

Neither method measures biological behaviour, and neither is a safety assessment. A chromatographically pure peptide of confirmed mass is a well-characterised chemical; that is all the analysis claims.

Purity figures also do not describe how much of the vial's mass is peptide, since a lyophilized solid also contains counter-ions and residual water. That is a separate measurement.