The Application of Electrochemical Tools for In Situ Measurements in Aquatic Systems

Abstract

Since the 1970's, when the ®rst in situ measurements of oxygen in the oceans were reported, the development of electrochemical sensors for in situ measurements in aquatic systems has signi®cantly intensi®ed. A synthesis of the progress made in limnology and oceanography to measure chemical species in situ is presented. From amperometric and potentiometric sensors that can measure a single analyte to voltammetric sensors that can measure several species during the same scan, a variety of electrodes have been used in situ to better understand the nature of the biogeochemical processes occurring in aquatic systems. The advantages and disadvantages of each technique, the technical improvements over the years, and some recommendations are presented together with representative data reported in the literature over the last two decades.

Siderophores Are Not Involved in Fe(III) Solubilization during Anaerobic Fe(III) Respiration by Shewanella oneidensis MR-1

“…The voltammetric conditions used in triplicate cathodic square wave voltammetry (CSWV) measurements included preconditioning at Ϫ0.9 V for 10 s and deposition at Ϫ0.1 V for 10 s to concentrate Fe(III) species at the electrode surface. A scan rate of 200 mV s Ϫ1 from Ϫ0.1 to Ϫ1.8 V with a pulse height of 0.05 V was used as previously described (10,59,60,62 ) by CSWV in degassed medium, and the pilot ion method was used to quantify concentrations of Fe(II). Voltammograms were integrated using a semiautomated software program developed for these applications (6).…”

Shift of algal community structure in dead end lagoons of the Delaware Inland Bays during seasonal anoxia

“…A 3-electrode voltammetric system was deployed in situ to measure real time dissolved O 2 and H 2 S concentrations with high vertical resolution and low detection limits (Brendel & Luther 1995, Luther et al 1998, Taillefert et al 2000. This 3-electrode voltammetric system consisted of a solid state Au/Hg PEEK TM microelectrode coupling with a solid-state Ag/AgCl reference electrode and a Pt counter electrode.…”

Development of a Novel Cu(II) Complex Modified Electrode and a Portable Electrochemical Analyzer for the Determination of Dissolved Oxygen (DO) in Water

“…However, metal complexes based on Ru and Os are expensive, then cheaper devices are desirable for practical applications. On the basis of their simple functioning and low cost, electrochemical devices have been used as transducers for dissolved oxygen sensing [3]. In this regard, the development of electrochemical devices for dissolved oxygen sensing based on transition metal complex is strongly encouraged because, compared to simple organic or inorganic materials, they offer a larger selection of molecular structures, the possibility of high environmental stability and a variety of electronic properties due to the coordinated metal center.…”