Ultra-pure water is required for the semiconductor fabrication and pharmaceutical industries. One extremely important water quality parameter is dissolved organic carbon content. The electronics industry currently limits total organic carbon (TOC) content of semiconductor fabrication process waters to >10 ug/L. The majority of analytical instruments which are currently available to monitor TOC at these levels utilize specific conductance detection of the dissolved HC03-/CO2= species which result from the photo-oxidation or combined chemical oxidation and photo-oxidation of dissolved organics. We propose an investigation of methods which can be used to improve sensitivity of TOC monitoring instruments by a factor of up to two orders of magnitude by chemically amplifying the conductivity signal. The proposed technology is based upon the transport of C02, resulting from the oxidation of dissolved organic species, across a semipermeable membrane into a alkanolamine solution where ionic compounds are formed by chemical reaction with C02-. Successful development of a TOC detection methodology which provides substantially lower limits of detection than can be achieved using currently available instrumentation is expected to result in the design, manufacture, and marketing of an advanced generation of instruments for ultra-pure water characterization in support of semiconductor and pharmaceutical industries. The new detector will be suitable for use in both laboratory instruments and continuous flow process analyzers.
