Distribution Equilibria of 2-(2-Pyridylazo)-5-methylphenol and Its Zinc(II) Chelate between Two Phases Separated from a Micellar Solution of a Nonionic Surfactant
Tóm tắt
Distribution equilibria of 2-(2-pyridylazo)-5-methylphenol (PAP-5-Me) and its zinc(II) chelate have been studied between two phases which were formed from a micellar solution of poly(oxyethylene)-4-nonylphenyl ether with 7.5 oxyethylene units (PONPE-7.5). One phase was rich in PONPE-7.5 and the other was the aqueous phase. The volume ratio of the former to the latter was about 0.6:49.5 under the present conditions. On the basis of the distribution curves for PAP-5-Me and zinc(II) as a function of pH, the acid dissociation constant of PAP-5-Me, the formation constasnt of the chelate, and the partition constants of PAP-5-Me and the chelate were determined at 293 K and ionic strength of O.I(NaCI).
Tài liệu tham khảo
H. Watanabe, N. Yamaguchi and H. Tanaka, Bunseki Kagaku, 28, 366 (1979).
H. Hoshino, T. Saitoh, H. Taketomi, T. Yotsuyanagi, H. Watanabe and K. Tachikawa, Anal. Chim. Acta, 147, 339 (1983).
K. Haraguchi, M. Miyajima and S. Ito, Bunseki Kagaku, 29, 416 (1980).
M. Y. Vanderstappen and R. E. Van Grieken, Talanta, 25, 653 (1978).
G. P. Hildebrand and C. N. Reilley, Anal. Chem., 29, 258 (1957).
K. Kiyokawa and A. Kawase, Bunseki Kagaku, 21, 244 (1972).