Comparison of two express immunotechniques with polyelectrolyte carriers, ELISA and FIIAA, for the analysis of atrazine.
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.
Krämer
Petra M
PM
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.
Franke
Annette
A
Zherdev
Anatoly V
AV
Yazynina
Elena V
EV
Dzantiev
Boris B
BB