Detection of Phenolate with a Solvent Polymeric Membrane Electrode

In this paper, a novel potentiometric method for the determination of phenolate is described. It is based on the controlled release behavior of permanganate ion by the tridodecyl-methylammonium chloride (TDMAC) based polymeric membrane ion selective electrode (ISE). The ISE membrane is used to control the release of permanganate ion for the redox reaction between permanganate and phenolate. The corresponding electromotive force (EMF) response is found determined by the activity of permanganate ion at the phase boundary, and will increase with consumption of permanganate ion. The controlled release of permanganate thus significantly improves the sensitivity of the electrode. The proposed membrane electrode exhibits an excellent performance for continuous and reversible detection of phenol at concentrations in 0.1 M NaCl ranging from 1.0 times 10^-7 to 1.0 times 10^-3 M with a detection limit of 5.4 times 10^-8 M.