Certificate of Analysis Forgery
Certificate of analysis forgery is the presentation of a fabricated, altered or recycled analytical document as though it recorded testing of the specific batch a buyer is receiving.
A certificate of analysis is a claim about one batch, made by a named laboratory, using stated methods. Forgery attacks each link. The document may be wholly invented; a genuine certificate with the lot number, date or purity figure edited; one real certificate reused across every batch a seller ships for a year; or an authentic report describing different material entirely. Nothing in a PDF binds it to the vial in hand, so a certificate is only as good as the chain connecting it to the product.
The tells are structural rather than cosmetic. A purity figure with no chromatogram, or an image too coarse to read; no stated method, column, gradient or detection wavelength; identity asserted without a mass spectrum; an observed mass quoted to more decimal places than the instrument class supports; no net peptide content and no water content; an issuing laboratory that cannot be found or will not confirm the report; and the same integration trace appearing under two different lot numbers.
This narrows what the document can be used for. A certificate is evidence when the batch identifier on the vial matches it and the issuing laboratory will independently confirm having produced it; otherwise it is marketing collateral in the visual language of a laboratory report.
The deeper error is overreading a genuine certificate rather than missing a forged one. A purity percentage is an area proportion of what eluted and was detected at one wavelength: it does not measure counterion mass, residual water, sterility or endotoxin, and it does not establish that the main peak is the intended molecule rather than a close analogue or a diastereomer. Buyers routinely treat an unforged certificate reporting a high purity number as a comprehensive quality statement, which it never was.