You are here:
IMMUNOCHEMICAL DETERMINATION OF DIOXINS IN SEDIMENT SAMPLES
Citation:
Nichkova, M., M. Chow, M. E. Koivunen, Kamita, S,G., S. J. Gee, J. C. Chuang, J M. Van Emon, AND B. D. Hammock. IMMUNOCHEMICAL DETERMINATION OF DIOXINS IN SEDIMENT SAMPLES. Presented at EPA EnviroExpo: Moving Toward Balance, Las Vegas, NV, December 9, 2004.
Impact/Purpose:
More cost-effective field screening and monitoring methods will be provided to increase the amount of information available concerning the location, source, and concentration of pollutants. Rapid and sensitive immunoassays such as enzyme-linked immunosorbent assays (ELISAs) to monitor remediation and cleanup activities at Superfund sites will be developed. Each new method will be tested on real-world samples from monitoring studies. Field studies will be conducted when time and resources permit. The feasibility and application of immunosensors to provide field analytical methods for the dynamic monitoring of hazardous substances of interest to the EPA will also be investigated. Concern has been expressed for the potential exposure of individuals to toxic compounds who live near hazardous waste sites or who may become exposed through other means. Thus, the development of methods for measuring biomarkers for human exposure assessment studies is also addressed.
During the remainder of the Task several projects will be undertaken including:
- Complete the development and evaluation of bioanalytical methods for dioxin and related compounds
- Perform dioxin immunoassay analysis on samples from a dioxin SITE demonstration
- Comparison of an ELISA with gas chromatography (GC) for monitoring polychlorinated biphenyls (PCBs) in soils/sediments collected from a Superfund field demonstration
- Survey of bioanalytical methods and sensor technologies for environmental monitoring
- Development of immunoaffinity chromatography sample preparations for PCBs
- Preparation of standard operating procedures (SOPs) for each bioanalytical method developed
- Conduct yearly research meeting
- Conduct survey of high priority chemicals at National Priorities List (NPL) sites for bioanalysis suitability
- Develop new bioanalytical methods for hazardous compounds of public concern
- Perform PCP immunoassay analysis on soil and sediment samples from a Superfund site and compare with GC data
- Preparation of fact sheets and journal articles
Description:
Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) are considered highly toxic contaminants with the environmental monitoring of these compounds being of great importance. Immunoassay procedures such as the enzyme-linked immunosorbent assay (ELISA) may be useful as screening methods to satisfy the growing demand for rapid and low-cost analysis of these compounds. In this work, we describe the application of an immunoassay for the screening of PCDDs and PCDFs in sediments. Sample extraction and preparation methods were developed with the aim to establish the simplest, cost-effective and efficient removal of matrix interferences for the ELISA. The overall method is based on a hexane extraction; cleanup by a multilayered (H2SO4/NaOH) silica gel column followed by an activated carbon column; an organic solvent exchange with DMSO-0.01% Triton X-100, the final step being ELISA measurement. The less toxic 2,3,7-trichloro-8-methyldibenzo-p-dioxin (TMDD) was used as a surrogate standard for 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). The estimated theoretical method detection limit for the determination of PCDDs/PCDFs was about 20 pg TMDD equivalents per g of dry sediment. The accuracy (60-113%) and the precision (13-33% RSD) of the ELISA method were evaluated through the analysis of spiked sediment samples. Gas chromatography-high-resolution mass spectrometry (GC-HRMS) validation studies were performed using13 samples. The validation revealed that the method is suitable for Toxic Equivalent Quantity (TEQ) screening of dioxins in sediments with a method detection limit of about 100 pg TMDD g-1 sediment. The study indicated that the immunoassay screening method offers improvement in speed, sample throughput, as well as cost, in comparison to GC-HRMS analysis.
The United States Environmental Protection agency (EPA) through its Office of Research and Development funded and collaborated in the research described here under contract No.68-D 99-01 to Battelle. Although this work was reviewed by EPA and approved for publication, it may not necessarily reflect official Agency policy. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.