Optical Fiber Sensor for Monitoring of Groundwater Trichloroethylene Levels

Advanced sensing technologies are needed to more efficiently address the requirements for the long- and short-term monitoring of groundwater, specifically for chlorinated hydrocarbons such as trichloroethylene. Current monitoring procedures can be expensive, as they generally require on-site visits to collect groundwater samples, or employ “portable” systems (gas chromatograph instruments), which are bulky and require transport by truck to multiple locations. There is a need for sensors that meet the required pollutant detection levels and are small, rugged, and at a reasonable cost for end users. Moreover, the sensor technique also should be handheld and meet specific end-user needs for shorter analysis times, good reproducibility, and easy-to-use functions. Intelligent Optical Systems (lOS) is developing a new approach to the monitoring of trichloroethylene (also known as trichlorethene, and abbreviated as TCE) and chlorinated hydrocarbons in groundwater. This monitoring technique is based on a colorimetric indicator that has excellent miscibility with lOS’s proprietary, highly permeable, optical cladding polymers. In Phase I, IOS demonstrated the feasibility of detecting TCE and other chlorinated hydrocarbon species in aqueous solutions using proprietary sensor cladding "thin film" formulations. In Phase II, the sensitivity and dynamic range will be optimized in the final sensor format, a “sensor chip.” A prototype handheld monitor will be fabricated, tested, and validated under the Environmental Technology Validation program at the Advanced Monitoring Systems Center. IOS' collaboration with Honeywell Analytics and RAE Systems, two of the world’s largest manufacturers and distributors of handheld monitoring devices, will enable it to design and fabricate a field-usable end product, and to provide diverse sales channels and draw on an existing customer base.