[Estradiol Reference Standard (Control 001) of National Institute of Health Sciences].

The raw material of tocopherol was tested for the preparation of "Estradiol Reference Standard (Control 991)". Analytical data obtained were: melting point, 178.5 degrees C: UV spectrum, lambda max of 281 nm and specific absorbance in ethanol at lambda max = 77.7; IR spectrum, same as that of the Estradiol Reference Standard (Control 964); optical rotation, [alpha]D20 = +79.5 degrees; thin-layer chromatography, one impurity was detected; high-performance liquid chromatography (HPLC), total amount of impurities estimated to be less than 0.6%; loss on drying, 3.3%; assay, 100.2% by UV spectrophotometry and 99.9% by HPLC. Based on the above results, the raw material was authorized as the Estradiol Reference Standard (Control 001) of the National Institute of Health Sciences.