reference material certification 

Synonym: certification of a reference material
https://doi.org/10.1351/goldbook.08118
Process that formally establishes the certified property value(s) of a candidate certified reference material.
Notes:
  1. The process is the responsibility of the reference material producer.
  2. Properties of a material include qualitative properties such as identities of chemical substances and quantitative properties such as mass concentration.
  3. The outcome of the process is a reference material certificate.
  4. Reference material certification is a "first-party attestation" in accordance with the definition of the term "declaration".
Source:
PAC, 2021, 93, 997. 'Metrological and quality concepts in analytical chemistry (IUPAC Recommendations 2021)' on page 1038 (https://doi.org/10.1515/pac-2019-0819)