探讨了硒测定的几种预处理方法, 采用一种程序控温的石墨消解系统来消化处理柑橘叶、 茶叶、 灌木叶、 圆白菜、 大米五种代表性的植物标准样品。 详细研究了这类植物样品前处理方法中消解液用量、 消解温度以及消解时间对植物样品中硒提取效果的影响； 优化了氢化物发生-原子荧光光谱法（HG-AFS）的仪器参数条件； 在氢化物反应条件中重点考察了还原剂KBH4浓度和酸度（HCl）对硒测定的影响, 不仅考虑了载流HCl浓度的影响, 还从样品HCl浓度就酸度对硒测定影响作了进一步细致研究, 从而建立了石墨消解-氢化物发生原子荧光光谱法测定这类植物样中痕量硒的最佳测定方法。 结果显示: 该方法中硒加标回收率在87.1%～106.2%, 检出限0.018 μg·L-1, 精密度RSD＜6.0 %, 标准物质的测试结果与参考值均相吻合； 在0～10 μg·L-1低标范围内和在0～100 μg·L-1 高标范围内, 荧光值与硒浓度均呈线性相关, 相关系数分别为r=0.999 9和=0.999 7。 因此该方法具有线性范围宽、 灵敏度高、 检出限低, 稳定性好的显著特点, 尤其适合如柑橘叶、 茶叶、 灌木叶、 圆白菜、 大米等这类批量植物样品硒的痕量分析, 且该方法操作简便安全, 实用性强, 仪器成本低, 所用试剂毒性小, 可作为一般实验室的常规分析方法。

Discussed several methods of pretreatment for the determination of selenium were discussed, and a program temperature-controlled graphite digestion method was developed to digest 5 kinds of representative standard plant samples of citrus leaves, tea, cabbage leaves, shrubs and rice. The effect of the pretreatment method of digestion solution, digestion temperature and digestion time on the extraction of selenium was investigated in detail. The instrumental working parameters were optimized. For the reaction conditions of hydride generation atomic fluorescence spectrometry (HG-AFS), the effect of the concentration of KBH4 and HCl on the determination of selenium was emphasized. Not only the effect of the concentration of carrier fiow HCl was considered, but also the effect of the concentration of sample HCl on the determination of selenium was studied. The best method for determination of trace selenium in plant samples by atomic fluorescence spectrometry with program temperature-controlled graphite digestion was established. Results indicated that the recovery of the method of selenium was 87.1%～106.2%, the detection limit was 0.018 μg·L-1 and the relative standard deviation (RSD) was less than 6.0%. In the range of 0～10 μg·L-1 (low standard) and 0～100 μg·L-1 (high standard) fluorescence was linearly related to the concentration of selenium, the coefficient of r was 0.999 9 and r was 0.999 7. Therefore, this method has wide linear range, high sensitivity, low detection limit and good stability, which was very suitable for the determination of trace selenium of plant. And the method was of easy and safe operation, strong practicability, low cost, and low toxicity of chemicals used, so it can be used as a routine analysis method in general laboratory.