New molecularly imprinted polymers (MIP) used as SPE clean up method and as a passive sampler receiving phase for the catchment of glyphosate and AMPA in water
Résumé
Glyphosate is a broad-spectrum systemic herbicide which is widely used in the world. As very polar molecules, glyphosate and its main degradation product AMPA are difficult to extract with organic solvents and common solid phase extraction (SPE) sorbents. A new SPE sorbent based on Molecularly Imprinted Polymers (MIP) was thus developed for Glyphosate and AMPA. The performance of the MIP is evaluated by the comparison between the classical method for the quantification of glyphosate and AMPA in water samples (on line SPE/UPLC/MS/MS after derivatization) with those obtained after MIP-SPE clean method followed with classical method. Results have shown that the MIP as a SPE clean up method allows the catchment both molecules in real water matrices which present different physico-chemical properties. The influence of metals concentration in samples on the recovery rates was also studied as metals are likely to form complexes with glyphosate in natural waters. This sorbent was also tested as an integrative passive sampler (POCIS) receiving phase since the classical version of POCIS with OASIS HLB receiving phase cannot catch these molecules of interest. The calibration of POCIS-MIP in laboratory conditions has led to laboratory sampling rates estimation for AMPA and glyphosate which are necessary for future field application of POCIS-MIP.