Spectroelectrochemical Sensor for Technetium Applicable to the Vadose Zone

Abstract

Progress Report RESEARCH OBJECTIVEThe general aim of this project i s to continue the design and implementation of a new sensor technology that offers the unprecedented levels of specificity needed for analysis of the complex chemical mixtures found at DOE sites nationwide. The new sensor concept combines the elements of electrochemistry, spectroscopy and selective partitioning into a single device that provides three levels of selectivity. The specific goal of this project is the development of a sensor for technetium (Tc) that is applicable to characterizing and monitoring the Vadose Zone and associated subsurface water at the Hanford site. The first goal is a sensor that determines technetium in the chemical form pertechnetate (TcO 4 -). RESEARCH PROGRESS AND IMPLICATIONSThis report summarizes work during 6/16/02 -6/15/03 of a four-year project that began on 9/15/99. During this period our efforts have focused on four areas that are discussed in the following sections. • Demonstration of fluorescence spectroelectrochemical detection • Demonstration of fluorescence of Tc-complexes • Demonstration of electrochemical modulation of fluorescence of Tc-complex • Development and characterization of selective films