Voltammetric Determination of Nitrates Using Silver Electrodes

Abstract

A silver disk electrode (diameter 0.2 mm) and composite silver electrode prepared from a mixture of silver, graphite powder and methacrylate resin (20 % Ag, 20 % graphite, 60 % methacrylate resin) are described. The electrodes prepared were used for the voltammetric determination of nitrate ions in samples of natural and wastewater (detection limit 7 mg L 71). The activation of the electrode surface before each measurement by a time-de®ned polarization ensures the reproducibility of the results of the voltammetric analysis. For the realization of such activation process the use of a computer-controlled instrument is necessary. For the electroanalytical measurement the advantages of the composite electrodes compared to solid silver electrodes includes simple preparation, low cost and electrochemical behavior typical to microelectrode arrays.

Anodic stripping voltammetry using graphite composite solid electrode

“…silver) electrode 5,9 . As the graphite solid composite electrodes do not contain any mercury, they present (as well as metallic composite 1,5,8,[10][11][12][13][14]32 , metallic 26,33,34 , solid amalgam and solid composite amalgam electrodes 9,35-39 ) an acceptable electrode material in all analytical laboratories.…”

Simultaneous Voltammetric Determination of Nitrate and Nitrite Ions Using a Copper Electrode Pretreated by Dissolution/Redeposition

“…Among many electrode materials, copper is expected to be the most effective material in terms of electroreduction of nitrate and nitrite ions. [15][16][17][18][19][20][21] Indeed, many studies have shown that pretreated and/or modified copper electrodes are effective for the determination of nitrate and nitrite ions. 13,14,[22][23][24][25][26] However, the pretreatments and/or modifications of copper electrodes in the studies seem to be complicated, time consuming and insufficiently sensitive for the determination of nitrate and nitrite ions in natural water samples.…”

Audio jack based miniaturized mobile phone electrochemical sensing platform

“…(8) Information from cloud server or social platform could also be retrieved to smart phone for analysis. at −1.5 V. This activation process will remove the possible oxidation layer at the surface of working electrode [20,21,35]. In order to avoid oxidation of silver working electrode and to make nitrate reduction happen, the sweeping voltage between working and reference electrode is chosen from 0 V to −1.5 V with a sweeping rate of 100 mV/s for cyclic voltammetry testing.…”

“…4(a), which shows a linear relationship with concentration. The fact that the peak potential is more negative compared with previous experiments from other research groups [15,16,35,36] can be attributed to more positive standard reduction potential of the reference electrode. This current peak is caused by the reduction of nitrate since the peak value increases with the increase of nitrate concentration.…”