ABSTRACT
AIM: To establish a sensitive and specific liquid chromatobraphy-mass spectrometry(time-of-flight)[LC-MS(TOF)] for the determination of astragaloside Ⅳ in rabbit plasma. METHODS: The HPLC-MS utilizing solid phase extraction was established to determine the concentration of astragaloside IV and ginsenoside R_~g1 , was used as internal standard. The analysis was carried on Agilent Hypersiol ODS(5 ?m, 4.6 mm?250 mm) column with a mobile phase of methanol-water (80∶20, v/v).Detection was performed on a time-of-flight mass spectrometry equipped with an ESI internal and operated in positive-ionization mode. Astragaloside Ⅳ quantitation was realized by computing the peak area ratio (astragaloside Ⅳ-ginsenoside R_~g1 )(astragaloside Ⅳ m/z807[M+Na]+ and ginsenoside R_~g1 m/z823[M+Na]+) and comparing them with calibration curve (r=~0.999 ). RESULTS: The linear calibration curve was obtained in the concentration range of 0.01-5 ?g?L~-1 .The detection limit of astragaloside Ⅳ was 0.01 ?g?L~-1 .The average recovery was more than 98%.The intra-and inter-run precision was measured to be below 5% of RSD. CONCLUSION: The method is sensitive, simple and rapid ,so, it can meet the need for the pharmacokinetics and bioavailability of astragaloside Ⅳ.