在线浓缩富集石墨炉原子吸收光谱法测定饮用水中硒的研究

目的: 建立在线浓缩富集石墨炉原子吸收光谱法测定饮用水中硒的方法。 方法: 利用Thermo Elemental Solaar M5原子吸收光谱仪的石墨炉升温工作程序,在一个分析测定程序周期内进行5次进样与干燥,在线浓缩富集5次后再进行灰化、原子化过程测定吸光度。硒空心阴极灯电流5.0 mA,测定波长196.0 nm,光谱通带宽度为0.5 nm。 结果: 在选定的实验条件下,0~25 μg·L^-1之间硒有较好的线性关系,相关系数为0.9981,检出限为1.38×10^-11g(n=11),15 μg·L^-1的硒标准溶液平行进样测定13次,所得硒吸光度的RSD为4.4%(n=13),加标回收率在94.8%~106%之间。 结论: 本法测定硒的精密度好,准确度高,本法可应用于实际饮用水水样中痕量硒的测定。

Objective: To establish an online concentrating graphite furnace atomic absorption spectrometry(GFAAS)method for the determination of trace selenium(Se)in water. Methods: By setting the temperature control program of Thermo Elemental Solaar M5 graphite furnace atomic absorption spectrometer,the sample injection,drying and online concentration processes were repeated 5 times within one analysis period and then the absorbance was measured after ashing and atomizing procedures.The electric current of the Se light was 5.0 mA,determined wavelength was at 196.0 nm,the slitwidth was 0.5 nm. Results: Under selected conditions,Se appeared to have a good linearity(r=0.9981)in the range of 0-25 μg·L^-1.The detection limit(n=11)was 1.38×10^-11 g.The results showed that RSD obtained by thirteen repetitions using standard solution with 15 μg·L^-1 of Se was 4.4%(n=13).The recoveries were 94.8%-106%. Conclusion: The proposed method has good repeatability and can be applied in the determination of trace Se in drinking water.