山药样品经硝酸和过氧化氢微波消解后,所得消解液在pH 11~12的介质中,加入0.1 mol·L-1氯化镧溶液达到共沉淀分离,所得沉淀经离心分离后用盐酸(1+1)溶液溶解,并用于氢化物发生-原子荧光光谱法分析。砷和硒的质量浓度均在40.0 μg·L-1以内与荧光强度呈线性关系,方法的检出限(3σ)依次为砷0.014 μg·L-1和硒0.022 μg·L-1。应用此法对山药样品进行分析,测得砷和硒的回收率分别为102%,96.8%。

Sample of Chinese yam was digested with HNO3 and H2O2, and the sample solution obtained was adjusted to pH 11-12 and 0.1 mol·L-1 LaCl3 solution was added for coprecipitation with As and Se. The precipitates were separated by centrifugation and dissolved in HCl (1+1) solution, which was used for HG-AFS determination. Under the optimum conditions, linear relationships between fluorescence intensity and mass concentration of As and Se were found in the same range within 40.0 μg·L-1, with detection limits (3σ) of 0.014 μg·L-1 and 0.022 μg·L-1, respectively. The proposed method was applied to the analysis of sample of Chinese yam, values of recovery found were 102% for As and 96.8% for Se.