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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 E lem ental SolaarM5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,0~25μg.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),15μg.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 method for the determination of selenium in drinking water by graphite furnace atomic absorption spectrometry. Methods: The working procedure of graphite furnace heating in Thermo Electron Solaar M5 Atomic Absorption Spectrometer was used. Five injections and drying were performed in one analysis and measurement cycle. The concentration and enrichment were performed on-line for 5 times and then ashing. The atomic absorption spectrophotometry was used to determine the absorbance . Selenium hollow cathode lamp current 5.0 mA, the determination wavelength of 196.0 nm, the spectral passband width of 0.5 nm. Results: Under the selected experimental conditions, there was a good linear relationship between the concentration of selenium and 0 ~ 25μg.L-1, the correlation coefficient was 0.9981, the detection limit was 1.38 × 10-11g (n = 11), 15μg.L -1 selenium standard solution was measured 13 times in parallel, the RSD of the obtained selenium absorbance was 4.4% (n = 13), and the recoveries were between 94.8% -106%. Conclusion: The determination of selenium with good precision and high accuracy, this method can be applied to the determination of trace amounts of selenium in the actual drinking water samples.