無機イオンのアゾトメトリー (第2報)

抄録

Separatory microdetermination of binary system metal ion mixture by the oxinebromate azotometry was attempted. The optimal pH at which the metal-oxine complex precipitates quantitatively differs with each ion and this was utilized in the separatory determination of Zn²⁺ and Mg²⁺, and Cd²⁺ and Al³⁺, estimable in the range of 10-200γ/cc. Before precipitating the metal-oxine complex, sodium cyanide was added as a masking agent, and the determination was made of Zn²⁺ in the presence of Hg²⁺, Cd²⁺ in the presence of Cu²⁺, and Al³⁺ in the presence of Fe³⁺. Determination of Mg²⁺ in the presence of Ca²⁺ was made by the use of ammonium oxalate as the masking agent. The estimable range in this case was also 10-200γ/cc. The determination of cadmium, zinc, and nickel was effected by the separation of Cd²⁺ and Zn²⁺ with cation exchange resin (Amberlite IR-120) and of Ni²⁺ and Zn²⁺ with anion exchange resin (Amberlite IRA-400), and subsequent oxine-bromate azotometry, the estimable range in this case being 50-150γ/cc.