Laboratory calibration of a POCIS-like sampler based on molecularly imprinted polymers for glyphosate and AMPA sampling in water
Résumé
For more than 15 years, integrative passive sampling has been successfully used for monitoring contaminants in water, but no passive sampling device exists for strongly polar organic compounds, such as glyphosate. We thus propose a polar organic chemical integrative sampler (POCIS)-like tool dedicated to glyphosate and its main degradation product aminomethylphosphonic acid (AMPA), and describe the laboratory calibration of such a tool for calculating the sampling rates of glyphosate and AMPA. This passive sampler consists of a POCIS with molecularly imprinted polymer as a receiving phase and a polyethersulfone diffusion membrane. The calibration experiment for the POCIS was conducted for 35 days in a continuous water-flow-through exposure system. The calibration results show that the sampling rates are 111 and 122 mL day(-1) for glyphosate and AMPA respectively, highlighting the potential interest in and the applicability of this method for environmental monitoring. The influence of membrane porosity on the glyphosate sampling rate was also tested.