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Biological Monitoring of 3-Phenoxybenzoic Acid in Urine by an Enzyme -Linked Immunosorbent Assay
Citation:
Chuang, J. C., J. M. VAN EMON, R. M. Trejo, AND J. Durnford. Biological Monitoring of 3-Phenoxybenzoic Acid in Urine by an Enzyme -Linked Immunosorbent Assay. TALANTA. Elsevier Science Ltd, New York, NY, 83(5):1317-1323, (2011).
Impact/Purpose:
The National Exposure Research Laboratory′s (NERL) Human Exposure and Atmospheric Sciences Division (HEASD) conducts research in support of EPA′s mission to protect human health and the environment. HEASD′s research program supports Goal 1 (Clean Air) and Goal 4 (Healthy People) of EPA′s strategic plan. More specifically, our division conducts research to characterize the movement of pollutants from the source to contact with humans. Our multidisciplinary research program produces Methods, Measurements, and Models to identify relationships between and characterize processes that link source emissions, environmental concentrations, human exposures, and target-tissue dose. The impact of these tools is improved regulatory programs and policies for EPA.
Description:
An enzyme-linked immunosorbent assay (ELISA) method was employed for determination of the pyrethroid biomarker, 3-phenoxybenzoic acid (3-PBA) in human urine samples. The optimized coating antigen concentration was 0.5 ng/mL with a dilution of 1:4000 for the 3-PBA antibody and 1:6000 for the enzyme conjugate. Urine samples were hydrolyzed with concentrated hydrochloric acid; extracted with dichloromethane and solvent-exchanged into a methanol/buffer solution, prior to analysis in a 96-microwell plate immunoassay. Quantitative recoveries of 3-PBA were obtained for fortified urine samples by ELISA (92±18%) as well as by gas chromatography/mass spectrometry (GC/MS) (90±13%). The overall method precision of these samples was within ±20% for both the ELISA and GC/MS methods. Analytical results from over one hundred urine samples showed that the ELISA and GC/MS data were highly correlated, with a correlation coefficient of 0.95. At the 10 ng/mL comparative concentration level, the false positive rate was 0% and the false negative rate was 0.8% for ELISA when using GC/MS as the reference method. The ELISA method has a suitable low detection limit for 3-PBA to assess pyrethroid exposures in non-occupational settings.
URLs/Downloads:
Biological Monitoring of 3-Phenoxybenzoic Acid in Urine by an Enzyme -Linked Immunosorbent Assay (PDF, NA pp, 179 KB, about PDF)Talanta
