Development of Electrochemical Techniques for the Detection/Quantification of Mercury using Boron-Doped Diamond ElectrodesEPA Grant Number: R829410E02
Title: Development of Electrochemical Techniques for the Detection/Quantification of Mercury using Boron-Doped Diamond Electrodes
Investigators: Seehra, Mohindar S. , Manivannan, Ayyakkannu , Smart, Ronald
Current Investigators: Seehra, Mohindar S.
Institution: West Virginia University
EPA Project Officer: Hunt, Sherri
Project Period: October 1, 2001 through September 30, 2003
Project Amount: $274,928
RFA: EPSCoR (Experimental Program to Stimulate Competitive Research) (2001) RFA Text | Recipients Lists
Research Category: EPSCoR (The Experimental Program to Stimulate Competitive Research)
The main objective of this research is focussed at meeting the need for the rapid on-site quantification of mercury emissions from coal-fired power plants in order to facilitate cost-effective control strategies for these emissions. Boron Doped Diamond (BDD) electrodes are novel electrodes utilized for the mercury analysis by electroanalytical method. It is expected that mercury concentrations in the range of ppb-ppt can be determined. Though, the spectroscopic techniques such as cold-vapor atomic fluorescence spectrometry (CV-AFS), cold vapor atomic absorption spectrometry (CV-ASS) and inductively coupled plasma spectrometry (ICP-MS) have been used successfully to detect mercury, they require large sample volumes and not suitable for on-line monitoring. Our present method using BDD electrode using electroanalytical technique is a simple and novel approach for mercury detection.
Differential pulse anodic stripping (DPAS) technique will be used for the present electroanalysis of mercury. Here the species of Hg2+ in solution are first deposited (reduced) electroanalytically onto an inert electrode at constant applied potential. A dc voltage ramp (mV/sec) is then applied in a direction that will cause the deposited material to be stripped (oxidized) from the electrode at a characteristic potential. This allows the separation of the charging current from the Faradaic current component, which is proportional to the concentration of the analyte. The peak position of the current at a specific potential due to metal stripping is indicative of the particular element and the amount of current represents the quantity of the element present. The use of ultrasound during mercury deposition on the BDD electrode will also be examined.
Preliminary results have demonstrated the high sensitivity and capacity of the BDD electrodes for mercury determination. Other electrodes such as glassy carbon have specific disadvantages on tedious preparation, pretreatment and high background currents. The present technique using BDD has the advantage to overcome such problems for the detection and quantification of mercury in the ppb-ppt range. Moreover, BDD can be used in harsh environments due to its inertness. Rapid on site detection and quantification of mercury will make a very important contribution to the solution of mercury problem in the environment.