Attenuated Total Reflectance (ATR) Sensor

We propose to develop a high sensitivity diamond tipped Attenuated Total Reflectance (ATR) sensor for cone penetrometer use for in situ, real time and continuous detection of dense non-aqueous phase liquids (DNAPLs). The detection scheme for the sensor will include the Combined Wavelength and Frequency Modulation Spectroscopy (CWFMS) employing tunable diode laser techniques and improved Fourier Transform Infrared (FTIR) spectroscopy. CWFMS was originally invented in the early nineties by Stevens Institute of Technology in NJ and furthr improved and commercialized by Princeton Electronic Systems.Examples of the analytes to be analyzed are: Trichloroethylene (TCE), tetracholoroethene (TeCE), methylene chloride, chloroform, carbon tetrachloride, benzene, toluene, xylenes, naphthalene.Advanced Chemometrics will be employed to achieve quantitative analysis of the above chemicals. In phase I, we will develop and demonstrate a prototype system for detection of TCE at a sensitvity of about 1 ppm, and in phase II develop a complete system for detection of TCE and other organic chemicals of interest to the Air Force at a sensitivity approaching 1 ppb.