Electroanalytical Flow Systems in Process Analysis
Interactions and optimization of voltammetric and chronopotentiometric techniques in online analytical systems
Based on the HIN Lecture by Prof. Ernest Beinrohr, January 31, 2022.
Autor: prof. Ernest Beinrohr
Department of Analytical Chemistry, Faculty of Chemical Technology, Slovak Technical University, Radlinského 9, SK-812 37 Bratislava, Slovak Republic & Department of Chemistry, University of SS. Cyril and Methodius, Trnava, Slovak Republic
Abstract
The lecture outlines the role of electroanalytical flow systems in process analysis, focusing on voltammetry and chronopotentiometry. Key components of modern online analysis are described, including sampling techniques (off-line, at-line, in-line, on-line) and monitored physical, chemical, and biological parameters. Emphasis is placed on automation, sensor miniaturization, cost-effectiveness, and robustness.
Electrochemical methods provide species-sensitive detection with high sensitivity, linear responses, and direct integration into flow systems. Chronopotentiometry is highlighted for its advantages in coulometric titrations and linear response in thin-layer configurations. Limitations, such as background currents and nonlinear effects, are discussed alongside techniques for signal enhancement and background compensation.
Applications span across environmental monitoring, industrial process control, and determination of trace metals, nonmetals, and organics in water samples. The potential of novel electrode materials, such as boron-doped diamond microarrays and microfluidic systems, is also introduced.
Introduction
Modern chemical industries and environmental monitoring require fast and reliable data — not only in the lab, but directly in the process. That’s where electroanalytical flow systems come into play: technologies designed to analyze chemical substances continuously and automatically.
What Are Flow Systems?
Flow systems move liquids through tubes, valves, and sensors. In an analytical setup, the sample flows directly into a measuring cell where the concentration of various substances is determined — often in real time.
They can be:
Off-line – sample taken to lab
At-line – sample measured nearby
In-line – in the flow, diverted
On-line – continuously monitored in the stream
Electrochemical Techniques: Voltammetry and Chronopotentiometry
These two techniques are the backbone of electroanalytical detection:
Voltammetry: measures current as voltage changes → suitable for trace metals, pollutants
Chronopotentiometry: applies constant current and measures voltage over time → excellent for titrations and concentration profiling
Advantages in Process Monitoring
High sensitivity
Minimal sample consumption
Automation-ready
Robust and low-cost design
These systems are used in:
Drinking water quality control
Wastewater management
Industrial effluents
Real-time metal detection
Advanced Materials: Diamond Electrodes & Microarrays
New generations of sensors use materials like boron-doped diamond. These electrodes resist fouling, offer low background noise, and work even in complex matrices.
Real-World Applications
Examples include:
Detecting bromates in tap water
Monitoring arsenic and cadmium in industrial solutions
On-line measurement of chromium(VI) via in-electrode titration
What’s Next?
The field is evolving with:
Microfluidics for greener chemistry
Immersible sensors for remote sites
Reagent-free systems reducing waste
Conclusion
Electroanalytical flow systems are transforming how we monitor and control chemical processes — making them faster, smarter, and more sustainable.
Based on the HIN Lecture by Prof. Ernest Beinrohr
Slovak University of Technology in Bratislava & University of SS. Cyril and Methodius in Trnava
Interested in this topic
or have a question?
Contact us directly for more information or to discuss potential collaboration.
