HPLC determination of three steviol glycosides in Stevia rebaudiana Bertohi

Objective: To develop a method for the determination of rebaudioside A,rebaudioside C and stevioside in Stevia rebaudiana Bertohi by HPLC. Methods: The analytes were separated on a Poroshell 120 EC C 18 column( 4. 6 mm ×150 mm,2. 7 μm),eluted by 30% acetonitrile and 70% phosphoric acid water solution,identified by UV detector at 210 nm and quantified by external standard method. Results: The limits of detection( LOD,S / N = 3) and quantification( LOQ,S / N = 10) were 1. 0- 1. 2 mg·kg- 1and 2. 5- 3. 0 mg·kg- 1respectively. The correlation coefficients of linear calibration curves were 0. 9999- 1. 000 in the range from 50- 1000 mg·L- 1. The recoveries of rebaudioside A,rebaudioside C and stevioside were 92. 8%,87. 2% and 90. 3% and the RSDs were 3. 9%,2. 7% and 4. 8%. The precision RSDs were 1. 2%,2. 1%,1. 3% respectively,and the repeatability RSDs were 3. 3%,6. 4% and 4. 7% respectively. Conclusion: The experiment results indicate that the method is simple and rapid with good separation and accuracy,and can be used for the quality control of the raw material of Stevia rebaudiana Bertohi.