ELISA and HPLC methods for atrazine and simazine determination in trophic chains samples

The aim of the research was to determine optimal conditions for atrazine determination in trophic chain samples by means of an antigen-coated tube enzyme-linked immunosorbent assay (ELISA). The ELISA method was used for analysis of a selection of samples and the results and method requirement compared with HPLC. The 2 h competitive ELISA showed a minimum detection limit of 0.05 ng mL(-1) and a dynamic range 0.1-2 ng mL(-1). Investigation of atrazine concentration in a selection of trophic chain samples indicated that the content of atrazine (microg kg(-1)) in soil samples was 3.2-85.4, vegetable roots 32.9-148.9, green parts of plants 67.7-136.4, cereals 42.4-91.5 and samples of animal origin 1.3-8.4. The correlation between results obtained by HPLC and ELISA methods was 0.97. In addition, simazine content was determined by the HPLC method in which the detection limits were 0.2 microg g(-1) for atrazine and 0.3 microg g(-1) for simazine. The content (microg kg(-1)) of simazine in soil samples was 13.5-15.5, in vegetables roots 29.5-93.7, in green parts of plants 34.6-72.6 and in cereals 158-189. The study demonstrates the utility and convenience of the simple, practical and cost-effective ELISA method in a non-immunoassay laboratory for the analysis of food and environmental samples. The method is ideal for the rapid screening of large numbers of samples in laboratories where access to HPLC facilities is limited or lacking. In addition the investigation demonstrates the presence of significant levels of atrazine and simazine in trophic chain samples collected from different areas of the region. As expected, the highest concentration of both herbicides was found in plants.