Development of Elisa Technique for the Analysis of Atrazine Residues in Water

Abstract

A highly sensitive enzyme immunoassay is described for the detection of atrazine residues in water. Atrazine derivative was conjugated to Bovine Serum Albumin (BSA) to obtain an immunizing antigen and to Horseradish Peroxidase enzyme (POD) to obtain a marker for immunoassay. The formation of these conjugations was confirmed by UV spectroscopy as well as by gel-electrophoresis. Polyclonal antibodies were raised in rabbits by immunization with an atrazine-BSA conjugate containing 29 atrazine residues per BSA molecule. An ELISA on microtitration plates was optimized with peroxidase-atrazine conjugate. The middle of the test (50% B/Bo) was found to be at 90 ng/l, which is well below the maximum concentration permitted by the EC guidelines for drinking water. Detection limits for atrazine of about 1 ng/l could be reached. The assay did not require concentration or cleanup steps for drinking or ground water samples. Validation experiments showed good accuracy and precision. No cross-reactivities were shown by other s-triazines like terbutryn, ametryn, terbuthylazine, des-isopropylatrazine, and de-ethylatrazine except hydroxyatrazine. The latter was present at very low levels that can be calibrated/standardized before analysis or it may be considered as leftover residues of atrazine. Based on these results, it is suggested that this test can be applied to obtain fairly accurate results for atrazine concentration in water samples from different sources.

Development of a Portable Immunoextraction-Reversed-Phase Liquid Chromatography System for Field Studies of Herbicide Residues

“…However, current techniques have several limitations when considered for such an application. For instance, ELISAs have become popular for the on-site screening of environmental samples; however, these methods have only moderate accuracy and precision and give a result that is affected by any compound that binds to the antibodies they employ as reagents. − GC and HPLC are more accurate and precise but generally involve laboratory-based methods that require the transport and storage of large quantities of sample. In addition, GC and HPLC often require several sample pretreatment steps (e.g., derivatization or solid-phase extraction) for environmental analytes that may result in additional products, coextracted interferences, or contaminants from the pretreatment step. , Furthermore, the lag between the time of sample collection and analysis in these methods is of concern, since some herbicides can have a large and rapid change in concentration during high-use seasons (e.g., during or following their application)…”

“…For instance, ELISAs have become popular for the on-site screening of environmental samples; however, these methods have only moderate accuracy and precision and give a result that is affected by any compound that binds to the antibodies they employ as reagents. [16][17][18] GC and HPLC are more accurate and precise but generally involve laboratory-based methods that require the transport and storage of large quantities of sample. In addition, GC and HPLC often require several sample pretreatment steps (e.g., derivatization or solid-phase extraction) for environmental analytes that may result in additional products, coextracted interferences, or contaminants from the pretreatment step.…”

Direct hapten coated immunoassay format for the detection of atrazine and 2,4-dichlorophenoxyacetic acid herbicides

“…In many previous studies polyclonal antisera as such have been used for estimat- ing the levels of different pesticides [18][19][20][21][22][23]. In the present study, we have demonstrated the use of highly purified antibodies using a combination of Protein-A sepharose column followed by passing through carrier protein column.…”

Enzyme-linked immunosorbent assay and immunochromatographic strip for rapid detection of atrazine in water samples

“…Immunoassays can meet these requirements. Numerous related methods for the detection of atrazine have been reported, such as enzyme-linked immunosorbent assay (ELISA) [10][11][12][13][14][15], colloidal gold-based immunochromatographic (ICG) strip assay [16][17][18], time-resolved fluorescent immunoassay (TRFIA) [19] and liposome immune lysis assay (LILA) [20]. The specific features of each study are listed and compared in Table 1.…”