Towards an integrated approach for the survey of aquatic systems quality: development and use of complementary and innovative analytical strategies and bioindicators – MIP_WQT

Several MIPs have been developed for a family of pesticides, triazines, of pharmaceuticals (carbamazepine and benzodiazepines) and some of their metabolites. For a given target, several conditions of synthesis were screened by studying, first in pure media, the presence of «imprint« cavities and their ability to selectively trap a selection of compounds from each
family. The most promising adsorbents were then applied to the selective extraction of target analytes in order to improve the sensitivity and reliability of LC/MSn analyses, following grab water sampling.
Some MIPs have also been integrated into integrative samplers to ircumvent some drawbacks of commercial POCIS devices and as a complementary approach to grab sampling in real waters.
In parallel, the differences in responses observed on real samples treated or not upstream by MIPs using biological methods (using amphibian and fish larvae targeting estrogenic and thyroid disturbance) were studied in order to better understand the cocktail effects.

- Screening of the conditions of synthesis of MIPs and development of selective extraction
procedures for the three targeted families and some of their metabolites.
- Development, optimization and studies of the performance of targeted analytical methods for each family of molecules using conventional extraction sorbents or MIP adsorbents coupled to LC/MS for their
determination in surface water samples during a field campaign
(grab samples and POCIS extracts).
- Preliminary results with bioassays.

The results related to the development of MIPs obtained in this project should make it possible to transpose them to other molecules and other fields for which analytical needs are important. They also highlighted the difficulty to produce MIPs for certain classes of molecules covering a wide range of polarity. While the contribution of MIPs is obvious for some molecules, the range of molecules that a MIP is able to selectively trap remains limited, leading in the future to the production of several MIPs to cover the entire structural family.

The results of this project already gave rise to 1 multi-partner oral communication, 4 posters and 2 oral communications involving only one partner in international scientific meetings and to 1 poster and 3 oral communications at national-level. The results obtained with the triazine MIP should result in at least one multi-partner publication and those on the other
compound families to at least 2 publications implying only one-partner and several other multi-partner publications.

The project aims to implement innovative molecularly imprinted polymers (MIPs) based strategies, with integrated and complementary analytical and bioanalytical approaches allowing more effective monitoring of relevant pollutants at ultra-trace level in waters in order to: i) enable a more reliable- and representative-monitoring of relevant pollutants at ultra-trace level; ii) improve the understanding of mode of action of the selected pollutants focusing on endocrine disruption; iii) enhance the knowledge of cocktail effects in natural environments and iv) sustain the innovation and competiveness in environmental metrology at the national level.
Thus, we propose to develop selective extraction sorbents inducing a retention mechanism based on the molecular recognition of the target compounds. Those sorbent will be used for selective extraction of real samples thus rendering their quantitative analysis more reliable and sensitive. Molecularly imprinted polymers (MIPs) are synthetic polymers that possess specific cavities and that are therefore considered as antibody mimics, the cavities allowing a selective trapping of the target analytes as the recognition sites of antibodies. Several MIPs will be developed. A MIP will be developed for the selective trapping of atrazine, of some structural analogs (simazine, terbutryne, terbuthylazine) and of their main metabolites (deethylatrazine, deisopropylatrazine, desethylterbutylazine). Another MIP will be dedicated to the selective trapping of carbamazepine and its epoxy- and dihydroxy-forms and another one for benzodiazepines such as oxazepam, diazepam, etc... At last, an innovative screening approach based on the design of a MIP to selectively extract the glucuroconjugated compounds whatever the chemical group they belong in combination with High Resolution Mass Spectrometry (HRMS) approach will be developed. Each time, for a given target, several conditions of synthesis will be screened and the resulting MIPs will be evaluated by studying the occurrence of selective cavities and their ability to selectively trap structural analogs and metabolites.
These synthetic sorbents will then be integrated in the sample pretreatment method for the selective extraction of the target analytes with a high degree of purification thus allowing to improve the reliability of the results in LC/MSn and their sensitivity. These MIPS will also be integrated in passive accumulative sampler as an alternative to the already available POCIS devices and to complement grab sampling thus allowing to accumulate and detect low level of contamination and mixtures of compounds including transformation products in real conditions. Those sampling devices will be treated by conventional analytical methods or detection by HRMS allowing the identification in the case of the glucuroconjugates. In parallel, the MIPs will be used as SPE sorbents in the existing on-line extraction system combined with UV spectrophotometry detection to increase the selectivity of the on-site monitoring device.
In parallel to chemical analysis, the project aim to implement thyroid and estrogenic disruption assays, based on the use of aquatic larvae (amphibian and fish) with and without a previous clean-up on MIP to evaluate and better understand cocktail effects. The different methods, devices and procedures, concerning well-known and non target compounds, will be implemented on real conditions (monitoring of two sites -ground and surface waters-). They will be assessed with respect to conventional approaches and monitoring strategies, considering their effectiveness, robustness, metrological performances, ability to highlight pollution impacts, environmental cost and suitability.
Chemometry is also included at different critical stages of the project especially experimental design and interpretation of monitoring data to maximize its efficiency and make more obvious the knowledge and lessons of the project.