HPLC DETERMINATION OF ATRAZINE AND PRINCIPAL DEGRADATES IN AGRICULTURAL SOILS AND ASSOCIATED SURFACE AND GROUND-WATER

A method for the quantitative estimation of atrazine and its principal degradation products in agricultural soils and associated surface and ground water is described. Bonded-phase extraction through cyclohexyl cartridges is used to isolate two principal degradates of atrazine from both surface and ground water samples. Soil is first extracted with organic-free water followed by dilute hydrochloric acid under heated conditions in a microwave extraction system. Reversed-phase HPLC employing an acetonitrile-water gradient is used for separation of analytes on a stabilized C18 analytical column. Analytes are detected by monitoring multiple wavelengths using a photodiode array detector. Identification is by retention time and molecular absorption spectra matching against reference standards. Terbuthylazine serves as a surrogate analyte. Method validation involved determination of percentage recovery for all analytes from fortified soil material and from spiked water. Amendment levels ranged from 0.10 to 10.0 mug/L for water and from 100 to 10 000 mug/kg for soils. Nominal limit of detection is 0.4 mug/kL for water and 40 mug/kg for soils.