Atrazine residues in soil two years after the atrazine ban : a comparison of enzyme immunoassay with HPLC

Abstract Two years after the atrazine ban in Germany, 417 soil samples from corn fields were screened for atrazine. The analyses were carried out by an enzyme immunoassay (EIA) using polyclonal antibodies from sheep. Thirty five samples contained more than 100 μg atrazine per kg of soil and were considered positive, indicating this year application. The concentrations of all positive samples and several negative samples were validated by HPLC. A correlation of r = 0.96 was obtained. When two different extraction methods using water or acetone were compared, no difference in atrazine yields were found with the EIA. The EIA proves to be a useful screening method, as long as positive samples can be validated by other methods such as HPLC or GC. *Dedicated to Prof. Dr. Dr. h. c. H. Ziegler, TU Munchen, on the occasion of his 70th birthday.