Analyte

A substance for which an analysis is being performed on

Defined more specifically in PDA TR57 Analytical Method Validation and Transfer for Biotechnology Products as "a specific chemical moiety being measured, which can be intact drug, biomolecule or its derivative, impurity, and/or excipients in a drug product" and a synonym to "measurand". More simply, an analyte is the target which an analytical method is detecting and providing information for. An example of an analyte is product residue on an equipment which is being tested by a product specific method such as high pressure liquid chromatography to determine the concentration.