Properly designed monolayer-protected nanoparticles (2 nm core diameter) can be used as nanoreceptors for selective detection and identification of phenethylamine derivatives (designer drugs) in water. The molecular recognition mechanism is driven by the combination of electrostatic and hydrophobic interactions within the coating monolayer. Each nanoparticle can bind up to 30–40 analyte molecules. The affinity constants range from 10⁵ to 10⁶ M⁻¹ and are modulated by the hydrophobicity of the aromatic moiety in the substrate. Detection of drug candidates (such as amphetamines and methamphetamines) is performed by using magnetization (NOE) or saturation (STD) transfer NMR experiments. In this way, the NMR spectrum of the drug is isolated from that of the mixture, allowing broad-class multianalyte detection and even identification of unknowns. The introduction of a dimethylsilane moiety in the coating monolayer allows performing STD experiments in complex mixtures. In this way, a detection limit of 30 μM is reached with standard instruments.

The increasing use of chemicals requires a better understanding of their presence and dynamics in the environment, as well as their impact on ecosystems. The aim of this study was to validate the first steps of an innovative multi-omics approach based on metabolomics and 16S metabarcoding data for analyses of the fate and impact of contaminants in Mediterranean lagoons. Semi-targeted analytical procedures for water and sediment matrices were implemented to assess chemical contamination of the lagoon: forty-six compounds were detected, 28 of which could be quantified in water (between 0.09 and 47.4 ng/L) and sediment (between 0.008 and 26.3 ng/g) samples using the UHPLC-MS/MS instrument. In addition, a non-targeted approach (UHPLC-HRMS) using four different sample preparation protocols based on solid/liquid extractions or an automated pressurized fluid extraction system (EDGE^®) was carried out to determine the protocol with the best metabolome coverage, efficiency and reproducibility. Solid/liquid extraction using the solvent mixture acetonitrile/methanol (50/50) was evaluated as the best protocol. Microbial diversity in lagoon sediment was also measured after DNA extraction using five commercial extraction kits. Our study showed that the DNeasy PowerSoil Pro Qiagen kit (Promega, USA) was the most suitable for assessing microbial diversity in fresh sediment.

The increasing use of chemicals requires a better understanding of their presence and their dynamics in the environment as well as their impact on ecosystems; it is therefore important to set up procedures. The aim of this study was to validate the first steps of an innovative multi-omics approach based on metabolomics and 16S metabarcoding data for future analyses of the contaminants fate and impact in Mediterranean lagoons. First, semi targeted analytical procedures for water and sediment matrices were set up to evaluate the lagoon contamination status. Forty-six compounds were detected, 28 could be quantified in both water (between 0.09 and 47.4 ng/L) and sediment (between 0.008 and 26.3 ng/g) samples using UHPLC-MS/MS instrument. Regarding the non-targeted metabolomics study (UHPLC-HRMS), four sample preparation protocols, based on solid/liquid extractions and an automated pressurized fluid extraction system (EDGE® extractions), were compared in terms of metabolome coverage, efficiency and reproducibility of the extraction methodology. A solid/liquid extraction using acetonitrile/methanol (50/50) solvent was the best protocol. On the other hand, in order to characterize the microbial diversity of the lagoon sediment using metabarcoding, five commercial kits for DNA extraction were evaluated. This study revealed that the DNeasy PowerSoil Pro Qiagen Kit (Promega, USA) was the best compromise for studies assessing microbial diversity in fresh sediment.

De nombreux produits chimiques se retrouvent dispersés dans l'environnement avec des conséquences parfois néfastes pour les hommes et les écosystèmes. Parmi ces substances figurent les antibiotiques et les stéroïdes hormonaux. Peu de données sont disponibles quant à la présence et le devenir de ces substances dans l'environnement notamment pour le sol, par manque de méthodologies. Nous avons donc mis au point des procédures d'analyse de traces de ces contaminants émergents, dans l'eau et le sol. Nous avons développé des méthodes multi-résidus et inter-familles basées sur des analyses LCMS/ MS. Pour les échantillons aqueux, l'extraction est menée sur phase solide (SPE, OASIS HLB). Les MLQs sont comprises entre 0.09 et 34 ng/L. Pour la matrice solide, la procédure d'extraction est inspirée de la méthode appelée QuEChERS suivie d'une purification SPE. Elle a été validée et des MLQs entre 0.013 et 3 ng/g ont été atteintes. Les tétracyclines et les fluoroquinolones, ont été étudiées séparément car elles ont des propriétés physico-chimiques bien spécifiques les rendant difficiles à extraire correctement du sol avec une méthode inter-familles. La méthode développée sur la matrice sol a permis une étude statistique mettant en exergue l'impact de certains paramètres du sol sur les rendements d'extraction et les effets matrice. Les méthodes ont été appliquées à une étude en colonnes de sol pour obtenir des données sur le transfert, l'accumulation et la dégradation des composés dans le sol