石墨炉原子吸收光谱法测定高纯水中痕量钠离子

对高纯水中痕量钠离子的石墨炉原子吸收光谱(GFAAS)测定法进行了研究，建立了直接在石墨管平台上在线富集样品的方法。采用将样品分步多次直接加入石墨管平台中，同时进行分步多次灰化，最后一次测定的石墨炉原子吸收光谱测定法，达到了富集痕量钠离子、满足仪器检测灵敏度要求的目的，同时又避免了添加萃取溶剂沾污样品的可能。为防止实验用水和试剂背景值掩盖样品中待测离子浓度，作者在超净工作台环境下，将电渗析、蒸馏、亚沸蒸馏多级纯化手段串连使用，制备出了满足痕量离子检测要求的实验用水。方法检出限为0.086 μg·L-1,回收率在101%～104%之间。

Determination of Trace Sodium Ion in High Purity Water by Graphite Furnace Atomic Absorption Spectrometry

The present paper studied on the determination of trace Na+ in high purity water by graphite furnace atom absorption spectrometry. A method of directly on-line concentrating samples in graphite furnace, multiple charging, ashing, then determining once by directly charging into pools of graphite furnace, was set up. The goal of concentrating samples and avoiding contamination as well as raising sensitivity were finally achieved. To prevent the background of purity water and regent in experiment from covering the ion concentration of the sample, the authors prepared the high purity water and regent to meet the requirement of the experiment by electrodialysis in series with distillation and below-boiling-point quartz distillation at pure worktable. Satisfactory results of linearity and detection limit were obtained. The detection limit with this method was 0. 086 microg x L(-1) for Na+. The recovery was 101%-104%.