Superfund Innovative Technology Evaluation (SITE)
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|Field Measurement Technology for Mercury in Soil and Sediment
NITON's XLi/XLt 700 Series X-Ray Fluorescence Analyzers
NITON's XLi/XLt 700 Series X-ray fluorescence analyzers were demonstrated under the U.S. Environmental Protection Agency Superfund Innovative Technology Evaluation Program in May 2003 at the Oak Ridge National Laboratory (ORNL) in Oak Ridge, TN. The purpose of the demonstration was to collect reliable performance and cost data for the XLi 702 and XLt 792 and four other field m easurement devices for mercury in soil and sediment. The key objectives of the demonstration were: 1) determine sensitivity of each instrument with respect to a vendor-generated method detection limit (MDL) and practical quantitation limit (PQL); 2) determ ine analytical accuracy associated with vendor field measurements using field samples and standard reference materials (SRMs); 3) evaluate the precision of vendor field measurements; 4) measure time required to perform mercury measurem ents; and 5) estimate costs associated with mercury measurements for capital, labor, supplies, and investigation-derived wastes.
The demonstration involved analysis of SRMs, field samples collected from four sites, and spiked field samples for mercury. The performance results for a given field measurem ent device were compared to those of an off-site laboratory using reference method, “Test Methods for Evaluating Solid Waste” (SW-846) Method 7471B.
The sensitivity, accuracy, and precision m easurem ents were successfully com pleted for both instruments. Results with the XLi 702 were found to be very precise and accurate when compared to standard reference materials. During the demonstration, NITON required 17.5 hours (assumes one technician) for analysis of 197 samples. The measurement costs were estimated to be $7,786 for NITON’s XLi 702 rental option, or $39.52 per sample; $13.18 per sample excluding rental costs.
Results for the XLt 792 was found to be very precise and accurate when compared to standard reference materials. During the dem onstration, NITON required 17.5 hours (assumes one technician) for analysis of 197 samples. The measurement costs were estimated to be $9,396 for NITON’s XLi 792 rental option, or $47.69 per sample; $13.18 per sample excluding rental costs.
The XLi/XLt 700 Series Analyzers exhibited good ease of use and durability, as well as no major health and safety concerns. The analyzers are hand-held single units and extremely portable. The demonstration findings collectively indicated that the XLi/XLt 700 Series Analyzers are rapid, lightweight, hand-held portable field measurement devices for mercury in soil.