Remote electrochemical sensor for monitoring TNT in natural waters

An electrochemical sensor for remote continuous monitoring of the explosive 2,4,6-trinitrotoluene (TNT) is described. The probe relies on rapid and sensitive square-wave voltammetry at a submersible carbon-fiber working-electrode assembly, connected to a 50ft-long shielded cable. Operational conditions have been optimized to meet the specific requirements of remote operations. Tests with untreated river water, groundwater, and drinking water samples, spiked with TNT, displayed results similar to those obtained with synthetic buffer solutions. Due to the low detection potential of TNT, coexisting sample constituents do not contribute to the response. The use of ultrafast square-wave voltammetric scanning, without a regeneration step, leads to a rapid detection of dynamic concentration changes, low ppb detection limits, and high stability. Prospects for using the electrochemical probe for real-time monitoring of TNT are discussed.