Frontier Geosciences, Inc., proposes to develop a portable field analyzer for the determination of low levels of arsenic in waters. The instrument will employ the principle of hydride generation-microplasma-atomic fluorescence spectrometry, and it is anticipated that the instrument will be able to analyze approximately 20 samples per hour, with detection limits of approximately 0.1 µg/L. The method will use a novel type of hydride-generation vessel, in which the hydride-generation reaction can be conducted in a closed atmosphere, thereby protecting the operator from arsine exposure. The arsines formed in the vessel will be swept into the microplasma atomization cell, where they decompose and then are detected by atomic fluorescence spectroscopy. The field analyzer will be operated using portable power generators and controlled by a laptop computer. Portable devices of this kind are specifically requested by the U.S. Environmental Protection Agency (EPA) in their Small Business Innovation Research Request for Proposals for the year 2002, to eliminate the need to pack and ship samples to distant laboratories as well as to obtain real-time information at lower costs. Once EPA introduces the final new arsenic drinking water standard (currently proposed at 10 µg/L), demand for arsenic determinations in waters will rise sharply. The atomic spectrometric detectors used in current EPA-approved methods for arsenic determination cannot be operated in the field, while the currently available arsenic field test kits suffer from several serious disadvantages, including bad reproducibility, analyte losses, positive artifacts, long analysis times (> 30 minutes/sample), high detection limits (10 µg/L), and potential health hazards to the operator from arsine exposure. Therefore, a portable field instrument that can accurately detect arsenic at concentrations below 1 µg/L, with data quality matching the much more expensive laboratory analyses, would be invaluable—especially when time-sensitive decisions will depend on the results. In Phase I of this project, Frontier Geosciences, Inc. proposes to build and optimize a prototype atomic fluorescence detector and the novel closed hydride-generation vessel. The two then will be coupled to determine the analytical performance characteristics of this technology, and the suitability of this instrument for field analysis will be demonstrated. In Phase II, a market-ready instrument will be designed that (after modifications) also may be suitable for arsenic speciation and for the field determination of other inorganic priority pollutants, such as mercury or selenium. Supplemental
Keywords: small business, SBIR, arsenic, mercury, selenium, monitoring, drinking water, atomic fluorescence spectrometry, spectrometer, field analyzer
