Submitted to: Journal of Environmental Monitoring
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/10/2011
Publication Date: 11/1/2011
Publication URL: http://handle.nal.usda.gov/10113/57271
Citation: Xu, Z., Zeng, D., Yang, J., Shen, Y., Beier, R.C., Lei, H., Wang, H., Sun, Y. 2011. Monoclonal antibody-based broad-specificity immunoassay for monitoring organophosphorus pesticides in environmental water samples. Journal of Environmental Monitoring. 13:3040-3048. Interpretive Summary: Organophosphorus pesticides (OPs) have been widely used in agricultural and domestic applications for more than six decades. However, OP intoxication can occur in humans and animals. We have developed antibodies that recognize a broad group of commonly used OPs. Antibodies are substances that are produced by the immune system in response to foreign substances which enter the body. Once the antibodies to a foreign substance are isolated, they can be used in a method to detect the presence of that foreign substance. The antibodies that we isolated may be used in an easy-to-use test called an enzyme-linked imunosorbent assay, or ELISA, for the detection of OPs. In this work, we evaluated the ELISA under different situations and improved the sensitivity of it by five-fold. This designed method is capable of determining whether 13 different OPs may be present in environmental water samples. The evaluation conducted here demonstrated that this assay is ideally suited as a screening method for OP residues in environmental water samples prior to chromatographic analysis.
Technical Abstract: The extensive use of organophosphorus pesticides (OPs) in agriculture and domestic settings can result in widespread water contamination. The development of easy-to-use and rapid-screening immunoassay methods in a class-selective manner is a topic of considerable environmental interest. In this work, a heterologous competitive indirect enzyme-linked immunosorbent assay (ciELISA) with broad-specificity for OPs was applied to the detection of O,O-diethyl and O,O-dimethyl OPs in environmental water samples. The influence of several physicochemical factors such as ionic strength, organic solvents, pH, and Tween® 20 were investigated. The sensitivity improved by three to five-fold for most OPs after ciELISA optimization, and 13 OPs were determined at concentrations ranging from 0.017 to 30 ng/mL. The determination of spiked environmental water samples showed average recoveries from 81.5% to 115.1%, with the coefficient of variation (CV) ranging from 6.1% to 20.9%. The determination of OPs in blind water samples demonstrated that the assay is ideally suited as a screening method for OP residues prior to chromatographic analysis.