Flow injection immunoaffinity analysis (FIIAA) — A screening technology for atrazine and diuron in water samples Original Research Article

An automated, computer controlled flow injection immunoaffinity analysis (FIIAA) system was used for screening water samples of different origin, e.g., groundwater, surface water for the presence of diuron and atrazine, respectively. Here, an in-house prepared column material with Protein A was used in the affinity column, which showed very similar features compared to the commercial material used previously. The in-house prepared material could be regenerated for more than 1000 times. The results obtained by FIIAA were compared with conventional analysis (gas or liquid chromatography, respectively) and with enzyme-linked immunosorbent assay (ELISA). The later used the same immunoreagents as the FIIAA. All three methods showed comparable results. ELISA and FIIAA showed in a few cases higher concentrations than those determined by chromatography, which are mainly caused by the cross-reactivities of the antibodies and probably some matrix effects. In a few cases false negative results were observed, which should not be present in a screening method. For the majority of samples though, the FIIAA system proved to be a very good screening tool for different water matrices.