Voltammetric ion selective electrode for the determination of nitrate

Abstract

A sensor which uses an anion-exchange membrane to enclose a small volume electrolysis cell has been demonstrated to be suitable for nitrate determinations. The three-electrode cell includes a constrained mercury column indicator electrode; filter paper, which is impregnated with a 0.1 M KCI-0.01 M ZrOCI2 electrolyte, serves as the constraining barrier and as the spacer for the thin-layer electrolysis chamber. The anion-exchange membrane sheath permits transfer of nitrate from the sample into the electrolysis chamber by Donnan dialysis and excludes several species which would otherwise interfere.Controlled potential electrolysis at -1.25 V vs. Ag/AgCI provides the sensing current, the value of which is proportional to the sample concentration of nitrate. As a steady-state current is not developed with the present design, a defined current sampling time is used. Linear response over 3 orders-of-magnitude nitrate concentration is obtained. The detection limit using the current at 8 min is 6.7 X 10~® M N03.

Selective electrocatalytic method for the determination of nitrite

“…In addition, the catalytic deposit is suitable for inclusion in a voltammetric ion selective electrode similar to our recent design for nitrate (10).…”

“…The present study was undertaken to develop a selective method for the determination of nitrite in the presence of nitrate. Compatibility to our voltammetric ion selective electrode design (10) was also a consideration. The approach reported herein involves reduction at a mercury electrode which has been modified by deposition of a Mo-catalyst.…”

The Detection of Nitrate Using in-situ Copper Nanoparticle Deposition at a Boron Doped Diamond Electrode

“…Ion selective electrodes can be used to avoid the effects of common interferences. 1,2,5,11,12,35,[50][51][52][53][54][55][56][57][58][59][60][61][62][63] Some limits of detection using electrochemical methods are shown in Table 1.…”