Compact Electrochemical Flow System for the Analysis of Environmental Pollutants

Abstract

A compact flow system that includes two electrochemical transducers integrated in a miniaturized cell is reported. Each transducer shows an on‐chip thin‐film gold three‐electrode configuration. The cell was machined on polymethyl methacrylate substrates, together with the required minifluidic elements for sample conditioning and analysis. These include several pumps and valves that enabled the system to work in an automatic fashion. Its performance was assessed by analyzing copper, catechol and parathion, using different chronoamperometric approaches. A rapid and reproducible response, ease of use, simple data interpretation and low maintenance make the system amenable to be implemented in a portable instrument for on‐site environmental analysis.

Electrochemical Nanocomposite-Derived Sensor for the Analysis of Chemical Oxygen Demand in Urban Wastewaters

“…Application of the CuO/AgO Sensor in a Flow System. With the aim of performing these measurements online and in continuous mode, the CuO/AgO sensor was inserted in a flow system fabricated in our group, 35 together with a Nafionmodified gold transducer. This transducer incorporated the counter and the pseudoreference electrodes.…”

“…In comparison with in batch experiments (slope of 6.8 nA mg −1 L O 2 and LOD of 28 mg L −1 ), these calibration parameters were limited by the measurement conditions as well as by the flow cell and the integrated reference and counter electrodes. Regarding the flow cell geometry and taking into account that the measurements were carried out under quiescent conditions, the available glucose in the flow cell (dimensions 4 × 4 × 0.5 mm 3 ; volume of 8 μL) 35 may be completely oxidized during the time frame of the analysis (30 s) taking into account the growth of the diffusion layer thickness of a diffusion-controlled electrochemical process. This may be contributing to the abovementioned decrease in sensitivity of the device.…”

Electroreductive Remediation of Halogenated Environmental Pollutants

“…A review of paper-based microfluidic devices that can be employed for on-site environmental monitoring in the field was recently published by Meredith and co-workers . A compact flow system equipped with a pair of electrochemical transducers in a miniaturized cell was fabricated by Gutiérrez-Capitán et al for the trace analysis of copper­(II), catechol, and parathion in aqueous environmental samples. Nouanthavong and colleagues developed a rapid and accurate paper-based assay for the colorimetric measurement of organophosphate pesticides, including chlorpyrifos ( 30 ); the detection limit for the latter compound was 5.3 ng mL –1 .…”

Microstructural, Impedance Spectroscopic and Potentiometric Analysis of Ta2O5 Electrochemical Thick Film pH Sensors

“…Metal oxide based pH sensors overcome disadvantages of the glass pH sensor, keeping excellent sensitivity, long lifetime stability and ease of fabrication in large scale 4. In recent years, considerable interest has been focused on preparation of electrochemical sensors for environmental pollution monitoring 4, 6, 7.…”