Glossary
What is Assay?
The measured content of the main component in a material, usually expressed as a percentage by weight on an as-is, dried or anhydrous basis. Assay may be determined by titration, HPLC, GC or other validated methods, and the method matters: an HPLC assay against a reference standard and a non-specific titration can give different values for the same lot. The COA should state both result and basis.