SEMINAR: "An Electrochemical Platform for Truly Remote, 24/7 Sensing of Heavy Metals"

Dr. Richard P. Baldwin
When Oct 26, 2017
from 12:00 PM to 01:30 PM
Where Vogt Bldg., RM 311
Contact Name
Contact Phone 852-7485
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Abstract:  Heavy metal elements, such as As, Pb, Hg, and Cd, rank #1, 2, 3, and 7, respectively, on the top ten priority list of hazardous substances according to the Agency for Toxic Substances and Disease Registry at the over 1300 “Superfund” sites. Adding to this the recent events including the Animas River spill of gold mine waste water in August 2015, the recent contamination of drinking water with Pb in Flint, MI, and regulatory concerns over power plant effluents, the need for remote monitoring of heavy metals has never been more pressing. Conventionally, water quality monitoring for heavy metal contaminants is currently performed using techniques such as inductively coupled plasma mass spectrometry and graphite furnace atomic absorption spectroscopy. While these methods offer a high level of performance, they also require significant capital investment, sample preparation, and operation by trained personnel in a central laboratory. These approaches also rely on random (in both time and location) “grab sampling” where samples are collected on-site and then transported to the lab for later analysis. However, at best, this approach provides only a “snapshot” of the water quality at a particular time and place. To overcome these limitations and restrictions, we have been developing a new generation of miniaturized “smart” electrochemical sensors for monitoring heavy metals that is intended for continuous, on-site operation and is capable of “on-demand” monitoring with little to no direct operator intervention. The system is based on anodic stripping coulometry (ASC), which requires little to no calibration. The heart of the detection platform is a stopped-flow, µL-volume, thin-layer coulometry cell that integrates a microfabricated electrochemical sensor into a miniaturized fluidic manifold. A miniaturized control system is used to actuate lowcost pumps and valves, and a custom electronics platform, adaptable to remote and automated operation, to analyze the sample. Communication with the system can be achieved over existing wireless infrastructure. All stages of analysis including sample injection, sample analysis, and data transmission can be carried out autonomously. Detection is typically completed within one to several minutes. Proof-of-concept studies performed in the laboratory have shown the successful determination of arsenite at low-ppb levels, which meet the EPA guidelines for drinking water.

Speaker:  Richard Baldwin received his PhD in Analytical Chemistry from Purdue University in 1976 and has served on the faculty in the Department of Chemistry at the University of Louisville since then. His research has involved various areas and applications of electroanalytical chemistry and is currently focused on the development of miniaturized/microfabricated instruments for environmental monitoring. He is the author of more than 100 research papers in the field of electroanalysis and has served as Editor of Analytica Chimica Acta since 2000.

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