The National Institute of Standards and Technology (NIST) produces Standard Reference Materials (SRMs) of basically anything. That also means that things like peanut butter are among those SRMs. SRMs come with a Certificate of Analysis (CoA) and have a validity period attached.
Given that NIST makes sure to know almost everything about their SRMs, how do they determine the validity period? Complex matrices can have difficult to estimate long-term influences on all the compounds in the sample. If they are running stability studies, when do they start those and for how long do they run?
