ジメルカプトマレオニトリル-ニッケル(II)錯体による10^<-6>Mレベルの第4級アンモニウムイオンの電位差滴定

概要

論文の詳細を見る
On the equilibrium study of ion-pair extraction of anionic chelates with quatemary ammonium cations (Q^+), a new method is eamestly desired by which trace amount of Q^+ ion (10^<-6>M level) can be determined directly. Nickel(II)-dimercaptomaleonitrile complex [Ni(mnt)_2]^<2-> forms a stable ion-pair with Q^+ ion and is quantitatively extracted into chloroform (K_<ex>=[2Q^+, Ni(mnt)_2^<2->]_0/[Ni(mnt)_2~,2->][Q^+]^2=10^<23.85>where Q^+ is (n-C_6H_<13>)_4N^+). Based on this fact, potentiometric titration of Q^+ ion with Ni(mnt)_2^<2-> was carried out with poly(vinyl chloride) membrane electrode, containing(70〜80)%(w/w) of di-2-etylhexyl-phthalate, as an indicater electrode for Q^+ ion. Cetylpyridinium chloride can be titrated at 10^<-5>M level, and tetra-n-hexylammonium chloride, tetradecyl-dimethylbenzylammonium chloride and tri-n-octyl-ammonium chloride down to 10^<-6>M level. In the case of mixture of several kinds of Q^+ ions, only a single end point was observed and corresponds, to the total concentration of Q^+ ions. This method was also successfully applied to the aqueous solutions containing (0〜40)% ethanol, and to those satulated with chloroform.
社団法人日本分析化学会の論文
1977-04-05