assay

https://doi.org/10.1351/goldbook.A00470
A set of operations having the object of determining the value of a quantity. In analytical chemistry, this term is synonymous with measurement.
Sources:
PAC, 1993, 65, 2003. 'Glossary for chemists of terms used in toxicology (IUPAC Recommendations 1993)' on page 2016 (https://doi.org/10.1351/pac199365092003)
PAC, 1994, 66, 2513. 'Nomenclature for radioanalytical chemistry (IUPAC Recommendations 1994)' on page 2515 (https://doi.org/10.1351/pac199466122513)