Grantee Research Project Results
Final Report: Rapid Detection of Trace Endocrine Disrupting Chemicals in Complex Mixtures: A Full-Spectrum Deconvolution Technique with a UV-Transparent Passive Concentrator
EPA Grant Number: R832738Title: Rapid Detection of Trace Endocrine Disrupting Chemicals in Complex Mixtures: A Full-Spectrum Deconvolution Technique with a UV-Transparent Passive Concentrator
Investigators: Kibbey, Tohren C.G. , Sabatini, David A.
Institution: University of Oklahoma
EPA Project Officer: Aja, Hayley
Project Period: January 1, 2006 through September 30, 2010
Project Amount: $448,259
RFA: Exposure Measurement Tools for Endocrine Disrupting Chemicals in Mixtures (2005) RFA Text | Recipients Lists
Research Category: Human Health , Safer Chemicals
Objective:
The objective of this work was to develop a method for rapid monitoring and detection of endocrine disrupting chemicals in natural waters using a full spectrum deconvolution technique with simultaneous absorbance or fluorescence measurements. The method is coupled with a novel ultraviolet (UV)-transparent polymer-based concentrator to be used as a passive sampling device. The UV-transparent polymer-based concentrator serves both as a solid phase extraction medium to concentrate EDCs for analysis and exclude many compounds likely to interfere with detection (fines, macromolecules such as organic matter, ionic surfactants), and an analytical optical cell, allowing rapid EDC quantification without labor-intensive pre-concentration procedures.
The work was divided into three primary tasks, each with a specific purpose for achieving the objectives of the study:
Task 1: Development of the deconvolution method and measurement of basis spectra
Purpose: Further development of the deconvolution method to improve selectivity. Divided into three subtasks--Analysis of method performance; Analysis of the effects of unknown compounds; and Measurement of basis spectra for the spectral library.
Task 2: Development of the UV-transparent Polymer Concentrator
Purpose: Selection and characterization of a suitable UV-transparent polymer, and design of passive concentrator. Divided into three subtasks--Preliminary characterization and selection of polymers; Characterization of selected polymers; and Final design of concentrator.
Task 3: Validation of the method
Purpose: Testing of the method with natural and synthetic waters.
A substantial number of experiments were conducted to identify and characterize polymers to be used for the project, and to develop and refine deconvolution algorithms for deconvoluting mixed spectra to determine individual component concentrations. Measurements of partition coefficients and mass transfer rate constants also were conducted. Focused field testing activities at the EPA Experimental Stream Facility and within a wastewater treatment plant were used to test the method in flow-through environments and in the presence of complex mixtures of contaminants.
Summary/Accomplishments (Outputs/Outcomes):
The results of this work found that a rapid, ultra-low cost passive sampler system based on optical scans of a UV-transparent polymer can be used for both screening detections of unknown compounds and tracking changing concentrations of known compounds. Like any method, the method developed as a part of this work was found to have detection limits that varied with the compound being analyzed. As developed, the method worked best for hydrophobic compounds with significant UV absorbance (e.g., compounds with multiple aromatic rings); detection limits in the mid-ng/L range are possible for a wide range of EDCs. Other compounds, such as the hormones estradiol or estrone, could not be detected by the method at environmental concentrations. Testing of the method with laboratory mixtures found that the method was able to quantitatively distinguish concentrations of items present in six-component mixtures. The presence of high quantities of dissolved organic matter or turbidity in the source water did not have a significant impact on the selectivity of the method. Testing for concentrations of nonylphenol and triclosan in the EPA experimental stream facility showed significant agreement between sampler-measured concentrations and LC-MS/ELISA-measured values. That work also highlighted the importance of deployment method and its impact on water motion around samplers for determining concentrations. Preliminary work in a wastewater treatment plant context has provided very promising results that suggest the method has the potential to function well in highly complex mixed environments.
Conclusions:
The environmental significance of the work is that it has the potential to provide an ultra-low cost method that can be used for preliminary screening for the presence of a range of EDCs, and is particularly well suited to cases where cost is critical. The method could ultimately be used to allow highly detailed spatially- or temporally-distributed screening in cases where traditional methods would be cost prohibitive, and could be used to search for unknown compounds or track changing concentrations of specific compounds known to be present.
Journal Articles on this Report : 2 Displayed | Download in RIS Format
| Other project views: | All 4 publications | 2 publications in selected types | All 2 journal articles |
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Kibbey TCG, Chen L, Sabatini DA, Mills MA, Nietch C. Model stream channel testing of a UV-transparent polymer-based passive sampler for ultra-low-cost water screening applications. Chemosphere 2010;80(8):908-913. |
R832738 (2009) R832738 (Final) |
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Kibbey TCG, Chen L, Singhaputtangkul N, Sabatini DA. A UV-transparent passive concentrator/spectrum deconvolution method for simultaneous detection of endocrine disrupting chemicals (EDCs) and related contaminants in natural waters. Chemosphere 2009;76(9):1249-1257. |
R832738 (2009) R832738 (Final) |
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Progress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.
Project Research Results
- 2009 Progress Report
- 2008 Progress Report
- 2007 Progress Report
- 2006 Progress Report
- Original Abstract
2 journal articles for this project