Molecularly imprinted polymer applied to the determination of the residual mass of atrazine and metabolites within an agricultural catchment (Brévilles, France)

Atrazine, desethyl-atrazine and desisopropyl-atrazine have been measured in the soils of Brévilles watershed. Pressurised liquid extraction (PLE) technique was used for extraction followed by purification with terbutylazine molecularly imprinted polymers. This clean-up procedure allowed to remove interfering compounds from the sample extracts. Thus making easier the analyses by reversed phase liquid chromatography coupled with ion trap tandem mass spectrometry. This selective sample treatment for soil extracts allowed limit of quantification (LOQ) of 0.03 ng/g for atrazine and 0.05 ng/g for metabolites. The concentrations in soil samples ranged from 7.1 ng/g to <LOQ for atrazine and from 2.5 ng/g to <LOQ for metabolites. The total cumulated mass in the top 60 cm of the soil of the watershed was estimated at 1.4, 0.52 and 0.25 kg for atrazine, desethyl-atrazine and desisopropyl-atrazine, respectively. A fraction of this mass available for leaching could generate water infiltrating with concentrations higher than the drinking water limit, 7 years after the last application of atrazine.