Analytical Sciences

Abstract − Analytical Sciences, 26(7), 773 (2010).

Chemiluminescent ELISA for the BTEX Determination in Water and Soil
Elisabetta MAIOLINI,* Dietmar KNOPP,** Reinhard NIESSNER,** Sergei EREMIN,*** Luca BOLELLI,* Elida Nora FERRI,* and Stefano GIROTTI*
*Dipartimento di Scienza dei Metalli, Elettrochimica e Tecniche Chimiche, Università di Bologna, Via S. Donato 15, 40127 Bologna, Italy
**Institute of Hydrochemistry and Chemical Balneology, Technische Universität München, 81377 München, Germany
***Department of Chemical Enzymology, Faculty of Chemistry, M. V. Lomonosov Moscow State University, Moscow 119899, Russia
An indirect competitive chemiluminescence enzyme-linked immunosorbent assay (CL-ELISA) for the determination of benzene, toluene, ethylbenzene, and ortho-, meta-, para-xylenes (BTEX) in soil and water was developed. The assay was optimized concerning the coating conjugate concentration, anti-BTEX antiserum dilution, incubation time effect on primary and secondary antibody incubation, and temperature effect on the competitive step and tolerance to different organic solvents. The IC50 and lower limit of the detection (LDD90) values were 4.6 and 0.5 μg mL−1, respectively. While water samples could be analyzed directly, soil has to be extracted and diluted prior to immunochemical measurements. BTEX could be recovered from spiked soil with a yield higher than 60% using 5-min ultrasonication with methanol. Finally, the assay was applied to soil and water samples collected at a contaminated site in Italy, and was compared to GC-MS.