1968 Volume 17 Issue 7 Pages 847-854
Determination of ultra-micro amounts of alkali and alkaline earth metals by hydrogen flame ionization method had been reported previously by the authors {This Journal, 15, 27 (1966)}. This ionization method has high sensitivity, but lacks selectivity.
For determining individual metal ion in a solution, further improvement of the detector and combination of this method with ion exchange chromatography werenecessary.
A modified detector with a sample holder of ringformed platinum wire (Fig. 2) was constructed. A small volume of sample solution (generally 1 μl or less) was loaded on the holder, and was evaporated to dryness in the drying chamber. After drying, the sample was inserted into hydrogen flame, and the response from the collector electrode was recorded. The procedure was suitable for successive analysis, since the holder has eight seats for samples.
For chromatographic separation of these metal ions, zirconium phosphate was chosen as an ion exchanger. Using ammonium chloride and hydrochloric acid solutions as eluates, the separation was carried out as shown in Fig. 9.
Sodium and potassium in human serum (Table II), hot spring water (Table III) and reagent grade barium hydroxide (Table IV) were determined. The results by this method agreed well with those by the flamephotometry.
