Cross-reactivity with triazine

It also appears to be good tool for visually determining the presence or absence of triazine herbicides, and with a spectrophotometer, a semiquantitative estimate of concentration can be made if the immunoassay response is primarily from atrazine. However, immunoassay has some cross reactivity with triazines other than atrazine and can produce a positive response in the absence of atrazine. 

Cross Reactivity of Triazine Herbicide With the EIA and Recovery of the Compounds From Water Prior to GC Analysis... 

Reactive halogen crosslinkers are mainly specific for sulfhydryl groups at physiological pH, however at more alkaline pH values they can readily cross-react with amines and the imidazole nitrogens of histidine residues. Some reactivity with hydroxyl-containing compounds also may be realized, particularly with dichloro-s-triazine derivatives under alkaline conditions. 

TABLE II. Cross-Reactivity of Various S-Triazines Analogues with One Anti-Atrazine MAb... 

EIA have been used intensively for the determination of pesticides in surface and rainwater - and groundwater. A substantial number of these studies were carried out for triazine herbicides. This illustrates the widespread occurrence of these herbicides in the aquatic environment. Many groups have used commercial test kits, which allow the investigation of samples without time-consuming Ab production. Thurman et al., for example, used a Res-I-Mune kit (ImmunoSystems) for the investigation of triazines in surface and groundwater. The EIA was compared to GC/MS results obtained from samples that were extracted by SPE. Correlation coefficients between 0.91 and 0.95 were obtained after introducing cross-reactivity factors for each of the triazines in order to calculate a sum parameter for the GC. The majority of the samples contained only atrazine (up to 3 igL ). Therefore, the EIA results corresponded well with the atrazine concentrations obtained by GC/MS. 

Hapten monolayer electrode sensor assembly was used to detect triazine in a flow injection analysis mode. The interaction of the electrode with different antibody concentrations resulted in the formation of an antibody-antigen (Ab-Ag) complex which insulated the electrode towards the [Fe(CN)6] /Fe(CN)6] " redox probe and diis in turn resulted in no charge transfer. The extent of insulation depends on the antibody concentration and the time of exposure to the antibody solution. The decrease in amperometric response of the antigenic monolayer to corresponding antibody solution for a fixed time produces a quantitative measurement of the antibody concentration. Typical responses obtained for cyanazine-hapten monolayer electrode to different antibody concentrations is shown in Figure 4. The lowest detection limit achieved for cyanazine sensor was 4.0 pg/ml at a response time of few minutes and a less-than 2% cross-reactivity to atrazine, simazine and other metabolites. 

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