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United States Department of Agriculture

Agricultural Research Service

Research Project: DIOXINS AND OTHER ENVIRONMENTAL CONTAMINANTS IN FOOD Title: Development of a Magnetic Particle Enzyme Immunoassay and Its Application to the Measurement of Triclosan in Water and Wastewater

Authors
item Shelver, Weilin
item Kamp, L - ABRAXIS
item Church, J - ABRAXIS
item Rubio, F - ABRAXIS

Research conducted cooperatively with:
item Abraxis, Llc

Submitted to: Organohalogen Compounds
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 4, 2006
Publication Date: August 18, 2006
Repository URL: http://www.dioxin2006.org
Citation: Shelver, W.L., Kamp, L.M., Church, J.L., Rubio, F.M. 2006. Development of a magnetic particle enzyme immunoassay and its application to the measurement of triclosan in water and wastewater. Organohalogen Compounds 68.

Interpretive Summary: Triclosan is an antimicrobial agent that is incorporated into various household products such as soaps, deodorants, toothpastes, and toys to decrease germ contamination. Chemical structure of triclosan is related to environmental contaminants such as flame retardants and dioxins; therefore, numerous reports of triclosan in wastewater treatment effluents have raised concerns of environmental contamination and microbial resistance. Current analytical methods for triclosan require extensive cleanup procedures, are time consuming, and need expensive instrumentation. In this report, we generated a sensitive method to measure triclosan in different water sources that is easy to operate, rapid, and cost-effective.

Technical Abstract: A sensitive magnetic particle-based immunoassay for triclosan (5-chloro-2-(2,4-dichlorophenoxy)phenol) was developed. Rabbit antiserum was produced by immunizing the rabbit with 6-(5-chloro-2-(2,4-dichlorophenoxy)phenoxy)hexanoic acid-keyhole limpet hemocyanin. The triclosan ligand and horse radish peroxidase were conjugated via NHS and EDAC reaction. In a similar fashion, the triclosan antibody was coupled to magnetic particles. Water samples were spiked with 62.5, 125, 250, and 500 ppt and analyzed directly without any sample extraction or pre-concentration. The results showed that recoveries were 80% or greater and the % CV less than 10%. The ELISA can detect triclosan at 20 ppt and its metabolite, methyl-triclosan, at 15 ppt. The antibodies were able to recognize some low substitution polybrominated biphenyl ethers but lost their ability to recognize analytes when the ether linkage was eliminated. Application of the triclosan ELISA to water and wastewater treatment plants show that tap water and water at various purification stages for drinking water is essentially below or close to the limit of detection (20 ppt). The wastewater treatment plant has various concentrations of triclosan but, in general, the levels decrease following the processing plant flow (from 7093 ppt in primary effluent to 462 ppt in the final effluent). Taken together, a rapid, sensitive, accurate, and precise magnetic particle-based immunoassay has been developed for triclosan analysis, which can serve as a cost-effective monitoring tool for different water samples.

Last Modified: 11/20/2014
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