[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%.