Atrazine presence and fluctuation within well water in Midwestern Illinois: A preliminary study

Atrazine (2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine) is a restricted-use herbicide manufactured, formulated, and sold under various trademarks by several agrochemical companies. As an herbicide, atrazine is often used with corn, sorghum, and sugar cane production for the control of annual broadleaf and grass weeds. Atrazine is able to target broadleaf and grassy weeds because they are small seeded while being ineffective towards large seeded crops such as corn, sorghum, and sugar cane. This type of targeting makes atrazine the most commonly applied herbicide in the U.S. with an average of 51 million pounds of active ingredient applied per year, per 2006. The common metabolites of atrazine include deethylatrazine or DEA and deisopropylatrazine or DIA. Atrazine and atrazine metabolites can be found in ground and surface waters.;Monitoring programs and studies have been developed to track atrazine and atrazine metabolite levels that are transported throughout soil and aquatic systems. Acetochlor is another selective herbicide used for pre- and early post-emergent control of annual grasses and certain broadleaf weeds in corn, usually alongside atrazine. Soil-applied corn herbicides and degradates have shown to be the most prevalent agricultural pesticides found in terms of frequency of detection and levels observed. Peak concentrations have been monitored to occur in the spring driven by run-off. The type of water source had no consistent effect on the frequency or magnitude of detections for most analytes except for atrazine, which showed a significant trend. Reservoirs formed by dams were most likely to have an atrazine annualized mean concentrations (AMC) greater than 3 mug/L in a majority of the sites studied. Methods for the identification and extraction of atrazine and atrazine metabolites in water samples have been investigated and developed.;Several drinking water wells in a Midwestern region of Illinois were tested once a month for a year for the presence of atrazine and atrazine metabolites. The method used incorporated DPX-CX tips to extract the target compounds and the sample was tested using HPLC. Testing and statistical analysis provided evidence for the presence of atrazine and atrazine metabolites in the well water along with the months in which each compound was present. The results for atrazine metabolites DEA and DIA were not significant enough to report. Results for atrazine showed a significant relationship between atrazine concentration and date. Mean atrazine concentration in relation to date resulted in a Least Significant Difference of 4.574. Atrazine concentrations also showed to exceed the maximum allowable level of 3 ?mug of atrazine/L, or 3 ppb in most wells tested. Future should be done to optimize the method and provide more accurate testing of rural wells.