Low-Cost Potentiometric Sensor for Chloride Measurement in Continuous Industrial Process Control

Molecules. 2022 May 11;27(10):3087. doi: 10.3390/molecules27103087.

Abstract

Recently, the new updates in legislation about drinking water control and human health have increased the demand for novel electrochemical low-cost sensors, such as potentiometric ones. Nowadays, the determination of chloride ion in aqueous solutions has attracted great attention in several fields, from industrial processes to drinking water control. Indeed, chloride plays a crucial role in corrosion, also influencing the final taste of beverages, especially coffee. The main goal is to obtain devices suitable for continuous and real-time analysis. For these reasons, we investigated the possibility to develop an easy, low-cost potentiometric chloride sensor, able to perform analysis in aqueous mediums for long immersion time and reducing the need of periodic calibration. We realized a chloride ion selective electrode made of Ag/AgCl sintered pellet and we tested its response in model solutions compatible with drinking water. The sensor was able to produce a stable, reproducible, and accurate quantification of chloride in 900 s, without the need for a preliminary calibration test. This opens the route to potential applications of this sensor in continuous, in situ, and real time measurement of chloride ions in industrial processes, with a reduced need for periodic maintenance.

Keywords: ISE sensor; OCP; chloride determination; continuous monitoring; in situ measurements; industrial process control; low-cost sensor; potentiometry.

MeSH terms

  • Chlorides* / analysis
  • Drinking Water* / analysis
  • Electrodes
  • Halogens / analysis
  • Humans
  • Potentiometry

Substances

  • Chlorides
  • Drinking Water
  • Halogens

Grants and funding

This research was funded by “Arte, Moda e arredo in un Processo Elettrochimico innovativo con controllo da Remoto 4.0—circular Ecofriendly” (A.M.P.E.R.E.) CUP 3553.04032020.158000223_1492/CUP CIPE D14E20006370009 and “Innovativi processi di produzione a basso impatto ambientale di catene in acciaio e alluminio” (ACAL 4.0) CUP UNIFI 3553.04032020.158000165_1340/CUP CIPE D14E20006260009. C.F. gratefully thanks financial support from Dipartimento di Ingegneria “Enzo Ferrari” (DIEF), UniMORE, FARD 2021—linea di azione di tipo 3: “Materiali chirali per batterie al litio e celle a combustibile” and from Consorzio Interuniversitario Nazionale per la Scienza e Tecnologia dei Materiali (INSTM), fondi triennali: “INSTM21MOFONTANESI”.