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INTERIM REPORT ON THE EVOLUTION AND PERFORMANCE OF THE EICHROM TECHNOLOGIES PROCEPT RAPID DIOXIN ASSAY FOR SOIL AND SEDIMENT SAMPLES
Citation:
BILLETS, S. INTERIM REPORT ON THE EVOLUTION AND PERFORMANCE OF THE EICHROM TECHNOLOGIES PROCEPT RAPID DIOXIN ASSAY FOR SOIL AND SEDIMENT SAMPLES. U.S. Environmental Protection Agency, Washington, DC, EPA/540/R-07/001 (NTIS PB2007-104861), 2007.
Impact/Purpose:
The objective of this program is to promote the acceptance and use of innovative field technologies by providing well-documented performance and cost data obtained from field demonstrations.
Description:
A demonstration of screening technologies for determining the presence of dioxin and dioxin-like compounds in soil and sediment was conducted under the U.S. Environmental Protection Agency's(EPA's) Superfund Innovative Technology Evaluation Program in Saginaw, Michigan in 2004. The objectives of the demonstration included evaluating each participating technology's accuracy, precision, sensitivity, sample throughput, tendency for matrix effects, and cost. The test also included an assessment of how well the technology's results compared to those generated by established laboratory methods using high-resolution mass spectrometry (HRMS). The demonstration objectives were accomplished by evaluating the results generated by each technology from 209 soil, sediment, and extract samples. The test samples included performance evaluation (PE) samples (i.e., contaminant concentrations were certified or the samples were spiked with known contaminants) and environmental samples collected from 10 different sampling locations. The PE and environmental samples were distributed to the technology developers in blind, random order. One of the participants in the original SITE demonstration was Hybrizyme Corporation, which demonstrated the use of the AhRC PCR Kit. The AhRC PCR Kit was a technology that reported the concentration of aryl hydrocarbon receptor (AhR) binding compounds in a sample, with units reported as Ah Receptor Binding Units (AhRBU). At the time of the original demonstration, this particular technology was intended for use as a screening tool to rank samples from those inducing the greatest AhR activity to those inducing the least AhR activity rather than to provide highly quantitative dioxin concentration in units of toxicity equivalents (TEQ). After the SITE Dioxin demonstration, this technology was exclusively licensed to Eichrom Technologies. Eichrom focused their efforts on developing optimal sample preparation procedures for the assay and reporting TEQ values instead of AhRBU. The technology is now marketed under the trade name Procept Rapid Dioxin Assay. The developers and potential users of the technologies provided feedback after the demonstration. There was significant interest in evaluating the performance of these technologies on a site-specific basis. This would more closely represent the expected application of the technologies than was the case during the original demonstration, which targeted technology performance when challenged with a broad range of sample types. Consequently, a second test (referred to as the site-specific study) was conducted in which the developers were given a total of 112 samples that were segregated by site of origin. In contrast to the original demonstration, in which all sample information was unknown, environmental information for each site was provided to the developers to more closely represent the background information that would be available to contractors supporting a site-specific application. Each batch included some samples previously analyzed as part of the SITE Dioxin Demonstration and some unique samples in archive that were not used as part of the SITE Dioxin Demonstration, along with replicates and quality control (QC) samples. Only dioxin and furan concentrations were evaluated in this study. The developers were given the HRMS data from the SITE Dioxin Demonstration so that they would have the opportunity to utilize a site-specific calibration and knowledge regarding typical congener patterns at a particular site. Data analysis focused on analytical performance on a site-specific basis, and included an evaluation of comparability to the HRMS total dioxin/furan toxicity equivalents (TEQD/F) results, precision on replicate analyses, and QC sample results. This report describes the experimental design of the site-specific study, the analytical methods used, and comparisons of the TEQD/F results from the HRMS data to those reported by Eichrom Technologies Procept Rapid Dioxin Assay. The data generated and evaluated during the site-specific study showed that the TEQ data produced by the Procept Rapid Dioxin Assay was more comparable to the HRMS TEQD/F data than was the data reported using the Hybrizyme AhRC PCR Kit in the original SITE demonstration. The Procept Rapid Dioxin Assay could be used as an effective screening tool to determine areas of greatest concern for cleanup at a site and could help to minimize the number of more expensive analyses needed for specific analytes, particularly considering that the cost and the time to analyze samples is significantly less than that of HRMS analyses.