β Scribed by Richard I. Walker; William H. Shipman
No coin nor oath required. For personal study only.
Most methods currently utilized for the separation of ammonia from interfering compounds are based on the principle of gaseous diffusion of ammonia from an alkaline medium and absorption by an acidic mediuml-3.
This communication describes a simple method for separating ammonia from interfering substances. Zirconium phosphate is utilized as an inorganic cation exchanger to adsorb the ammonium ion thus separating it from interfering compounds. Once eluted, the ammonium ion can be oxidized by hypochlorite and reacted with phenol to form a compound whose absorbance obeys Beer's lawa.
For the preparation of sodium phenolate IOO g NaOH were dissolved in water and 120 g phenol added; the final volume was brought to 500 ml. Commercial grade clorox was used as the source of sodium hypochlorite. Zirconium phosphate (50-100 mesh) was supplied by Bio-Rad Laboratories.
Other chemicals used were concentrated nitric acid and cesium chloride.
The zirconium phosphate column (0.8 cm x 03 cm) is connected to two reservoirs by a s-way stopcock (Fig. I): Flow rates are controlled by a modification of the Mariotte principleG. The column is equipped with a removable cap to facilitate loading.
π SIMILAR VOLUMES
Kinetic ion-exchange experiments have shown that, under appropriate conditions, it is possible to replace the exchangeable protons present on the surface of Zr(HPO&-Hz0 micro-crystals with several divalent and trivalent cations, without exchanging the inner protons. This has made it possible to inve