Spectroelectrochemical sensing based on attenuated total internal reflectance stripping voltammetry. 2. Determination of mercury and lead.
Detection of lead and mercury by attenuated total internal reflectance spectroscopy coupled to stripping voltammetry is demonstrated. Changes in attenuation of light passing through an indium tin oxide optically transparent electrode (ITO-OTE) accompany the electrodeposition and stripping of lead and mercury on the electrode surface. The change in absorbance during stripping of electrodeposited metal constitutes the analytical response that enables detection over a range of 2.5 x 10(-7)-5 x 10(-5) and 5 x 10(-8)-5 x 10(-5) M for mercury and lead, respectively. The spectroelectrochemical responses of mercury and lead on the ITO surface are characterized and optimized with respect to solution conditions, the potential excitation signals used for deposition and stripping, and wavelength for detection. The deposited metals were examined by environmental scanning electron miscroscopy, and the electrodeposition pattern of lead and mercury was found to influence the optical response.
Department of Chemistry, University of Cincinnati, P.O. Box 210172, Cincinnati, Ohio 45221-0172, USA.
Anne T
AT
Maghasi
Sean D
SD
Conklin
Tanya
T
Shtoyko
Aigars
A
Piruska
John N
JN
Richardson
Carl J
CJ
Seliskar
William R
WR
Heineman
D004563:Electrochemistry; D004785:Environmental Pollutants / Q000032:analysis*; D007854:Lead / Q000032:analysis*; D008628:Mercury / Q000032:analysis*; D008855:Microscopy, Electron, Scanning; D013057:Spectrum Analysis / Q000295:instrumentation / Q000379:methods*; D017971:Tin Compounds
D004785:Environmental Pollutants; D017971:Tin Compounds; D007854:Lead; C109984:indium tin oxide; D008628:Mercury