Determination of Impurities in 17[beta]-Estradiol Reagent by HPLC with Charged Aerosol Detector

The charged aerosol detector (CAD) has recently become a new alternative detection system in HPLC. This detection approach was applied in a new HPLC method for quantification. We tried to use CAD for the quantification of impurities in a 17β-estradiol reagent. This detector could not analyze a high-concentration sample because of a baseline noise. The component of 17β-estradiol was removed by using a valve-switching device. Quantification of impurities in 17β-estradiol reagent was determined by a calibration curve of 17β-estradiol (USP). The results of quantification used by CAD with the calibration curve of 17β-estradiol were compared with those used by UV with the calibration curve of each standard of impurity. There was correspondence between the results of quantification using CAD and UV. By this result, we confirmed that CAD is useful in analyzing some impurities in the 17β-estradiol reagent.