| Abstract
| - A miniaturized field-portable immunosensor (FAST 2000)was field tested at former military munitions sites for thedetection and quantitation of TNT and RDX in groundwater.Developed by the Naval Research Laboratory (NRL) andengineered by Research International, Inc. (Woodinville, WA),the immunosensor performed on-site analysis of contaminated groundwater at three military bases identified by theU.S. Environmental Protection Agency (EPA) as prioritySuperfund cleanup sites. The locations were Naval SubmarineBase, SUBASE Bangor, Bangor, WA; Umatilla ArmyDepot Activity, Umatilla, OR; and Naval Surface WeaponsCenter, Crane, IN. The immunosensor uses an antibodyas the recognition element for the explosive molecule ina displacement assay format. Detection of the explosivemolecule contained in groundwater is confirmed byan increase in fluorescence over background from thedisplaced cyanine-labeled explosive analogue. At each site,groundwater samples containing unknown concentrationsof explosives were collected from monitoring wells andanalyzed on-site by the portable immunosensor with nosample pretreatment or concentration. Groundwater sampleswere split and shipped to an independent certified U.S.EPA laboratory for analysis using SW-846 Method 8330 (HPLC).Statistical analysis based on linear regression curvescomparing the immunosensor and the HPLC method showedgood correlation, although site-dependent problemswere encountered with some samples. The immunosensorrequired small sample volumes (150 μL/test) and lessthan 3 min to analyze samples with a method detectionlimit of 10 μg/L in the laboratory-spiked samples. The resultsfrom this field demonstration show the viability of theimmunosensor for on-site analysis of explosives to assistin environmental remediation and monitoring efforts.
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