Background:
Formononetin is a common soy isoflavonoid that can be found abundantly in
many natural plants. Previous studies have shown that formononetin possesses a variety of activities
which can be applied for various medicinal purposes. Certified Reference Materials (CRMs) play a
fundamental role in the food, traditional medicine and dietary supplement fields, and can be used for
method validation, uncertainty estimation, as well as quality control.
Methods:
The purity of formononetin was determined by Differential Scanning Calorimetry (DSC),
Coulometric Titration (CT) and Mass Balance (MB) methods.
Results:
This paper reports the sample preparation methodology, homogeneity and stability studies,
value assignment, and uncertainty estimation of a new certified reference material of formononetin.
DSC, CT and MB methods proved to be sufficiently reliable and accurate for the certification purpose.
The purity of the formononetin CRM was therefore found to be 99.40% ± 0.24 % (k = 2) based on the
combined value assignments and the expanded uncertainty.
Conclusion:
This CRM will be a reliable standard for the validation of the analytical methods and for
quality assurance/quality control of formononetin and formononetin-related traditional herbs, food
products, dietary supplements and pharmaceutical formulations.
Coulometric titration method for ferrous ion by electrolytically generated bromine