Analyst (Cambridge UK) 2011-04-07

Cetirizine as pH-dependent cross-reactant in a carbamazepine-specific immunoassay.

Arnold Bahlmann, Jana Falkenhagen, Michael G Weller, Ulrich Panne, Rudolf J Schneider

Index: Analyst 136(7) , 1357-64, (2011)

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Abstract

High performance liquid chromatography (HPLC) was hyphenated with a previously reported carbamazepine-specific enzyme-linked immunosorbent assay (ELISA) as a screening approach to water analysis in order to identify possible interferences from transformation products. Treated wastewater was analysed and three substances were recognized by the antibody besides carbamazepine: the metabolites 10,11-dihydro-10,11-epoxycarbamazepine and 2-hydroxycarbamazepine plus the structurally not obviously related antihistamine cetirizine. The molar cross-reactivity against cetirizine was found to be pH-dependent and assessed to be 400% at pH 4.5 and 22% at pH 10.5. Performing the ELISA at pH 10.5 greatly improved the accuracy when carbamazepine was determined in surface and wastewater samples.© The Royal Society of Chemistry 2011