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, 4 17 soil samples from corn fields were screened for atrazine. The analyses were canied out by an enzyme immunoassay (EIA) using polyclonal antibodies from sheep. Thirty five samples contained more than 100 pg 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 usefid screening method, as long as positive samples can be validated by other methods such as HPLC or Gc. 62 1

Approaches to the Immunochemical Analysis of Non-extractable Triazine Residues in Refractory Organic Substances (ROS) and Characterization of ROS

“…In contrast, Ab S2 and K4E7 were obtained with an atrazine aminocaproic acid-KLH immunoconjugate, exposing an isopropyl group and a chlorine atom at the s-triazine ring (Fig. 2) [16,28]. The same Ab binding pattern was observed when FA and HA from soil containing non-extractable residues were investigated by EIA [17].…”

“…Immunochemical methods such as enzyme immunoassays (EIA) have become increasingly popular as screening tools for the determination of pesticides because they are fast, less expensive, and easy to perform [e.g., [12][13][14]. Sensitivities are reached down to 10...20 ng/L [15,16], and only small sample volumes (a few milliliters) are necessary. Recently, EIA also have been applied for the determination of non-extractable atrazine residues in soil [17,18].…”

Nonextractable Pesticide Residues in Humic Substances: Immunochemical Analysis

“…These and closely related compounds can be assayed by a competitive EIA originally developed for the determination of atrazine in rain, surface water, and soil extracts (16,22). The rationale behind this point is the potential applicability of the atrazine EIA for the determination of non-extractable residues in soluble humic substances.…”

“…The samples were extracted with water for 12 hours on a shaker at 25 °C, and the extractable atrazine residues were determined by a competitive EIA and HPLC (16). The soil samples after extraction were then assayed by non-competitive EIA for non-extractable residues using peroxidase-labelled Fab fragments directed against atrazine.…”

Standardization of Immunoassays for Water and Soil Analysis

“…The following example is taken from a laboratory (12) which has been involved during the recent years in a monitoring program to assay soil samples for the pesence of atrazine, one of the most important herbicides in Germany before its ban in April 1991.…”