Rapid Detection of Trace Endocrine Disrupting Chemicals in Complex Mixtures: A Full-Spectrum Deconvolution Technique with a UV-Transparent Passive ConcentratorEPA Grant Number: R832738
Title: 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: McOliver, Cynthia
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: Health , Safer Chemicals
Suspected endocrine disrupting chemicals (EDCs) have been widely detected in the environment, and are a source of increasing concern. One of the major challenges in assessing risk associated with endocrine disrupting chemicals in the environment is that their environmental concentrations are typically extremely low – on the order of ng/L to m g/L – making them difficult to quantify without extensive pre-concentration procedures. Further complicating their detection is the fact that they are present in mixtures, sometimes with tens to hundreds of other compounds (pharmaceuticals, personal care products, detergents, natural organic matter).
The objective of this work is to develop a method for rapid monitoring and detection of endocrine disrupting chemicals at trace concentrations in natural waters, using a full spectrum deconvolution technique with simultaneous absorbance and fluorescence measurements. The method will be coupled with a novel ultraviolet (UV)-transparent polymer-based concentrator to be used as a passive sampling device. The UV-transparent polymer-based concentrator will serve 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 proposed work will be accomplished through three main research tasks: 1. Development of a robust full-spectrum deconvolution technique for detecting individual EDC compounds in complex environmental mixtures; 2. Selection and characterization of one or more polymers, and design of the concentrator; and 3. Validation of the method with waters and wastewaters. Spectrophotometric measurements will be conducted using dual-channel fiber-optic CCD-array spectrophotometers equipped with custom designed cells to hold the UV‑transparent polymer-based concentrators. The spectrophotometers will be configured for simultaneous fluorescence and absorbance measurements, and will be coupled with custom software for real-time data acquisition and analysis. Polymers for the concentrator will be selected from among the subset of polymers that combine significant UV transparency with hydrophobicity (largely silicones, fluorocarbons, or other advanced polymers), and will be fully characterized for EDC partitioning affinity and rate, as well as other critical physical properties. Compounds to be studied will include hundreds of EDCs and other compounds representing commonly detected compounds in natural waters, to provide an extensive library of spectra needed for accurate analyses.
The results of this work will provide a powerful screening tool for rapid detection and quantification of EDCs in natural waters. The resulting tool will provide a means of rapidly assessing the risk of EDC exposure posed by a specific ground- or surface water, without the need for extensive sample preparation and preconcentration, allowing far more waters to be tested than would be possible with current methods. Preliminary results indicate that the tool will be highly selective, identifying the presence of specific compounds and families of compounds with excellent accuracy.