Use the compound, test date, lot number, vendor, and reported result together. A laboratory attribution alone does not prove that a file is authentic or that the tested sample came from a particular retail vial.
A reported HPLC purity value describes the portion measured by that assay. It does not, by itself, establish identity, vial content, sterility, endotoxin status, chain of custody, or overall product quality.
Certificates carrying a Janoshik task number and unique key can be checked in the laboratory's own system. Compare the returned report with the document field by field; a match still does not establish vendor chain of custody.