Optimization of the Methods for the Determination of Selenium Content in Astragalus memeranaceus by Hydride Generation Fluorescence Spectrometry

The instrument parameters and current-carrying conditions for the determination of total selenium in Astragalus memeranaceus by hydride generation fluorescence spectrometry were explored, and the sample digestion methods were optimized, in order to establish the best conditions for the determination of total selenium in Astragalus memeranaceus by hydride generation fluorescence spectrometry. By taking the standard reference material of component analysis of Astragalus memeranaceus as the material, the optimal instrument conditions, current-carrying reagent conditions and digestion conditions were investigated and determined by using the single variable method, and finally the content of selenium in Astragalus memeranaceus was determined under the optimal conditions. The results showed that the optimum conditions for the determination of total selenium in Astragalus memeranaceus by hydride generation fluorescence spectrometry were as follows:the negative high voltage was 300 V, the lamp current was 80 mA, the reagent conditions were that the concentration of current-carrying hydrochloric acid being 2%, and the concentration of potassium borohydride solution being 12 g·L^-1, the digestion conditions were that the volume of hydrochloric acid being 5 mL, and the digestion time being 90 min. Under this condition, the content of selenium in Astragalus memeranaceus was 0.135 mg·kg^-1. The method was simple, accurate and suitable for the determination of selenium content in Astragalus memeranaceus.