[Determination of sennoside A and sennoside B simultaneously in health food by HPLC].

To develop an analytical method for determination of sennoside A and sennoside B simultaneously in health food by high performance liquid chromatography (HPLC). Samples were extracted by ultrasound extraction and determined by HPLC with a UV detector. Using a Synergi Hydro-RP (250 mm x 4.6 mm, 4 microm) column and a mixture of CH3CN: 1.0% CH3COOH (17:83) as mobile phase for separation. The detection wavelength was at 270 nm. The contents were calculated with an external standard. The linearity was good in the ranges of 1.40 - 28.0 microg/ml for sennoside A and 1.45 - 29.0 microg/ml for sennoside B. The average recovery rates of sennoside A and sennoside B were 85.2% -97.2% and 86.1% -96.2%. The RSD was 7.5% and 6.8%, the limit of detection was 0.8 mg/kg and 0. 6 mg/kg, and the limit df quantification was 2.1 mg/kg and 2.0 mg/kg for sennoside A and sennoside B respectively. The method is simple, accurate and suitable for the determination of sennoside A and sennoside B in health food.