A FIBER OPTIC AQUEOUS PHASE TRICHLOROETHYLENE SENSING INSTRUMENT

THE PURPOSE OF THIS PROGRAM IS TO DEVELOP A REAL-TIME CHEMICAL SENSING INSTRUMENT FOR DETECTING AND MONITORING OF CHLORINATED ORGANIC SOLVENT CONTAMINANTS, PARTICULARLY TRICHLOROETHYLENE (TCE). THE PROPOSED WORK IS BASED ON THE PRINCIPLE OF COMBINING SPECTROSCOPIC, ELECTROCHEMICAL AND FIBER OPTIC TECHNIQUES. SPECTRO-ELECTROCHEMICAL FIBER OPTIC SENSING (SEFOS) IS, IN PRINCIPLE, A GENERIC TECHNIQUE WHICH CAN BE ADAPTED TO MANY DIFFERENT SENSING APPLICATIONS. THE INCORPORATION OF SPECTROSCOPIC DETECTION, SUCH AS FLUORESCENCE, SHOULD ENABLE MANOMOLAR LIMITS (I.E., PPB LEVELS OR LESS), UNLIKE ELECTROCHEMICAL METHODS WHICH ARE GENERALLY LIMITED BY BACKGROUND CURRENTS DUE TO IMPURITIES AND NON-FARADAIC PROCESSES. THE TECHNIQUE HAS AN ADVANTAGE OVER CURRENT FIBER OPTIC CHEMICAL SENSING METHODS IN THAT THE SENSING ONLY TAKES PLACE WHEN THE ELECTRODE DEVICE IS TURNED ON. THIS ENABLES LONG-TERM MONITORING OF A WELL/SITE TO BE ACCOMPLISHED WITH ONLY ONE SEFOS PROBE. THE GOAL OF THE PHASE I PROGRAM IS TO TEST THE FEASIBILITY OF USING SPECTRO-ELECTROCHEMICAL METHODS FOR THE DETECTION OF THE CHLORINATED ORGANIC SOLVENT, TCE, IN THE RANGE OF AQUEOUS CONCENTRATIONS FROM 5 PPB TO THE SOLUBILITY LIMIT. THE GOAL OF THE PHASE II PROGRAM IS TO DEVELOP AND TEST A FIBER OPTIC BASED PROTOTYPE FIELD PORTABLE INSTRUMENT FOR THE FIELD SCREENING/IN SITU MONITORING OF TCE AND OTHER CHLORINATED ORGANIC SOLVENT CONTAMINATION.