Characterization and uncertainty evaluation of a new certified reference material of baicalein.

A new certified reference material (CRM) of baicalein was developed aiming to control the quality of baicalein and relative pharmaceuticals. Sample preparation, homogeneity, stability, value assignment, and uncertainty of a new certified reference material (CRM) of baicalein were presented in this paper. Characterization of the material relied on three different methods, which were differential scanning calorimetry (DSC), coulometric titration method (CT) and mass balance method. DSC and CT were used for purity determination of baicalein firstly. The certified value of baicalein CRM is 99.72% with an expanded uncertainty of 0.25% (k=2). The new CRM of baicalein can be used to validate analytical methods, improve the accuracy of measurement data as well as establish meteorological traceability of analytical results.