Determination of Selenium Species in Burdock and Panax Notoginseng Using Ultrasonic Assistant Extraction Combined with High Performance Liquid Chromatography-Inductively Coupled Plasma Mass Spectrometry
Abstract A HPLC-ICP-MS method for the analysis of selenocystine (SeCys 2 ), selenite [Se(IV)], selenomethionine (SeMet) and selenate [Se(VI)] was developed. In the experiment, chromatographic separation was performed within 8 min with 8 mM citric acid solution (pH 5) as mobile phase. The potentially interference of 40 Ar 40 Ar + to 80 Se + at the selenium masses of m / z 80 was reduced by CH 4 as a reactive cell gas in the dynamic reaction cell. The selenium with different species was extracted using ultrasonic extraction system with a mixture of protease K and lipase. The limits of detection for SeCys 2 , Se(IV), SeMet and Se(VI) were 0.088, 0.033, 0.30 and 0.17 ng mL −1 , respectively. The correlation coefficients were greater than 0.9995. The recoveries were in the range of 95.1%–114.6%. The developed method was successfully applied for the determination of selenium species in traditional Chinese medicine of Burdock and Panax notoginseng .