Highly silver ion selective fluorescence ionophore: fluorescent properties of polythiazaalkane derivatives bearing 8-(7-hydroxy-4-methyl)coumarinyl moiety in aqueous solution and in liquid-liquid extraction systems.
Two novel fluoroionophores, N-(7-hydroxy-4-methylcoumarin-8-ylmethyl)-3,9-dithia-6-azaundecane (1) and N-(7-hydroxy-4-methylcoumarin-8-ylmethyl)-3,9-dithia-6-azaundecane (2), were synthesized as fluorescence extractants for selective silver determination. The absorption and fluorescence spectra were measured in aqueous 1,4-dioxane solution (28 v/v%) in the absence and presence of silver ion, and their acid dissociation constants were determined from the pH-dependent spectral changes. In the liquid-liquid extraction of some metal ions from neutral aqueous solution into dichloromethane phase, compounds 1 and 2 exhibited excellent silver ion selectivity, and dramatic fluorescence spectral changes were observed in the dichloromethane solutions containing these compounds. The determination limit of 2 for silver ion was 2.0 x 10(-8) mol dm(-3) in the liquid-liquid extraction.
Sakamoto
Hidefumi
H
Department of Applied Chemistry, Faculty of Systems Engineering, Wakayama University, Sakaedani 930, Wakayama, Wakayama, 640-8510, Japan. skmt@sys.wakayama-u.ac.jp
Ishikawa
Junichi
J
Osuga
Hideji
H
Doi
Kunio
K
Wada
Hiroko
H