METHOD FOR LOW-COST IN SITU MEASUREMENT OF DISSOLVED TOTAL VOLATILE ORGANIC COMPOUND CONCENTRATIONS IN SURFACE WATERS.

Increases in volatile organic compounds (VOC) in developing areas poses risks to aquatic health. Water quality changes in surface waters, if measured, are often only for field parameters of pH, specific conductance, water temperature, and major ions, e.g. Ca2+, Mg2+, Na, Cl. Elevated VOC concentrations can negatively impact aquatic ecosystems even at low concentrations, but do not cause changes in commonly measured parameters and may go undetected based on monitoring these common parameters. Traditional sampling and benchtop analysis for VOC can be both time and cost prohibitive. Here we demonstrate the use of a low-cost in situ dissolved total VOC measurement platform consisting of a total VOC gas sensor in combination with a dissolved gas marble chamber system. Limitations of the current prototype include portability in remote areas and non-selectivity of specific VOC species. Measurement of total VOC in natural and engineered environments using the described platform, nonetheless, represents an affordable screening tool for potential organic contaminants. Combined with species specific VOC analysis, measurement of dissolved total VOC could provide as a VOC surrogate for high frequency monitoring.