Abstract:In order to accurately quantify the total amount of soil selenium, a method was established. The soil samples were digested in a graphite digestion instrument by 1+1 inverse aqua regia, and then the selenium concentration was determined by hydride atomic fluorescence spectrometry (HG-AFS). The effects of the ways of digestion , times and the work condition of apparatus for the determination of Se are discussed, the operating condition of apparatus was optimized. 5 mL 1+1 inverse aqua regia was added into 0.2 g soil standard material. The mixture was digested by the graphite digestion instrument at 120 °C for 1.5 h, and then adjusted to 25 mL with ultrapure water after cooling. The selenium concentration was determined by HG-AFS. The result showed that the selenium concentration of all soil standard materials within the theoretical range, the relative standard deviation was 2.6%, the recovery rate was 92.3~110%, and the detection limit was 0.68 ng/L. The selenium concentration of nine soil standard materials can pass by the method. The advantage of this method includes accurate result, simple operation, short digestion time, low cost and safety.