Solid-phase Extraction and High-performance Liquid Chromatographic Analysis of Prednisone Adulterated in a Foreign Herbal Medicine
YOE-RAY KU, YI-CHU LIU AND JER-HUEI LIN *
National Laboratories of Foods and Drugs, Department of Health, Executive Yuan, 161-2, Kun-Yang Street, Nankang, Taipei, 115 Taiwan
(Received : June 7, 2001; Accepted : July 23, 2001)
ABSTRACT
Prednisone was detected in a herbal medicine from Southeast Asia using thin layer chromatography (TLC) and ultraviolet spectroscopy (UV). After treating with solid-phase extraction (SPE), the sample was further assayed by high-performance liquid chromatography (HPLC). The sample solution was achieved with a silica gel cartridge conditioned with methanol and chloroform in sequence, and then eluted with dichloromethane-isopropanol (6:4, v/v). Separation was conducted with an Inertsil ODS-80A reversed-phase column using isocratic elution with acetonitrile and water (3:7, v/v) as mobile phase. Fludrocortisone acetate was used as an internal standard and detection wavelength was at 240 nm. Calibration curve of standard prednisone was constructed in the range of 10.0-200.0 mg/mL. The content of adulterated prednisone was 5.5 mg/21g sample.
Key words: HPLC, prednisone, solid-phase extraction, herbal medicine, adulterant