T. Katsu, Dafeng Xu, K. Tsuji
Nov 10, 1997
Citations
0
Influential Citations
20
Citations
Journal
Analytica Chimica Acta
Abstract
Abstract Phosphate esters, such as tris(2-ethylhexyl) phosphate (TEHP) and tricresyl phosphate, can be used as neutral carriers to make organic ammonium ion-selective membrane electrodes. For example, a hexylammonium ion-selective electrode was constructed using TEHP as the carrier and dioctyl phthalate as a membrane solvent in a poly(vinyl chloride) membrane matrix. The electrode exhibited a near-Nernstian response to hexylammonium in the concentration range from 2×10 −4 to 0.1 M with a slope of 57 mV per concentration decade. The lower limit of detection was 2×10 −5 M, was comparable to that of the electrode made from one of the amine ionophores, a calix[6]arene analog, reported previously. The interaction between the phosphate ester and hexylammonium was confirmed by 1 H-NMR spectroscopy.