This product is not considered an analytical standard. It meets the analytical specifications of the European, British, and United States Pharmacopeia, but is neither a primary nor secondary standard. It is intended for use in general research applications. See the links below to review additional products that may be of interest:
1134369, USP reference standard
https://www.sigmaaldrich.com/product/usp/1134368
A1202000, EP reference standard
https://www.sigmaaldrich.com/product/sial/a1202000
94676, Secondary reference standard, traceable to NIST/NMIJ
https://www.sigmaaldrich.com/product/sial/94676