title: Comparison of two express immunotechniques with polyelectrolyte carriers, ELISA and FIIAA, for the analysis of atrazine.
abstract: Conventional immunoassays on microtiterplates are very useful analytical tools in environmental analysis, but the long assay times, usually in the range of hours, are a drawback. To overcome this disadvantage, the development of fast (express) assay formats is described, which use polyelectrolytes as carriers. Two semi-homogeneous immunochemical methods, namely the polyelectrolyte-ELISA (enzyme-linked immunosorbent assay) and the express-FIIAA (flow injection immunoaffinity analysis) for the analysis of the herbicide atrazine were set-up. Using polyclonal antisera for atrazine, the following results were obtained. Standard curves for atrazine showed a linear range from 3 to 100mugl(-1) in polyelectrolyte-ELISA and 0.3-100mugl(-1) in express-FIIAA. The test midpoints in polyelectrolyte-ELISA and express-FIIAA were 12 and 5mugl(-1), respectively. The duration time of the immunochemical reaction was in both assays 15min, but the total assay time differed (30min (polyelectrolyte-ELISA) and 18min (express-FIIAA)). A significant difference between the formats could be observed in the number of samples that can be determined per day. The polyelectrolyte-ELISA can handle samples in parallel on a microtiterplate (usually 20/plate), whereas in the express-FIIAA the samples are automatically analysed one after another. This first demonstration of these techniques shows the potential of these methods, but also their limitations.
authors.affiliation: GSF, National Research Centre for Environment and Health GmbH, Institute of Ecological Chemistry, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany; Technische Universität München, WZW, Institute of Ecological Chemistry and Environmental Analysis, Weihenstephaner Steig 23, 85350 Freising-Weihenstephan, Germany.
authors.forename: Petra M
authors.initials: PM
authors.lastname: Krämer
authors.forename: Annette
authors.initials: A
authors.lastname: Franke
authors.forename: Anatoly V
authors.initials: AV
authors.lastname: Zherdev
authors.forename: Elena V
authors.initials: EV
authors.lastname: Yazynina
authors.forename: Boris B
authors.initials: BB
authors.lastname: Dzantiev