How to read a Certificate of Analysis

A Certificate of Analysis is the document that ties a physical vial to the analytical work performed on the batch it came from. Every lot we ship carries one, signed by the accredited laboratory that ran the assays.

The purity figure at the top comes from HPLC-UV quantification against a certified reference material. A figure of 99.4% means the main peak represents 99.4% of the total integrated area at the specified wavelength.

Mass spectrometry confirms identity: the observed molecular weight should match the theoretical weight of the sequence within a very narrow tolerance. If a COA lacks an MS section, purity alone does not confirm you have the right compound.

Finally, look for the lot number. It should match the number printed on the vial label. A COA that cannot be tied back to a specific lot is a marketing document, not a quality document.