Riadh Ternane

Simultaneous detection of antibiotics and other drug residues in the dissolved and particulate phases of water by an off-line SPE combined with on-line SPE-LC-MS/MS: Method development and application.

Due to their widespread use in human and animal healthcare, antibiotics and other drug residues are ubiquitous in the aquatic environment. Given their potential impacts on ecosystem functioning and public health, the quantification of environmental drug residues has become a necessity. Various analysis techniques have been found to be suitable for reliable detection of such compounds. However, quantification can be difficult because these compounds are present at trace or ultra-trace levels. Consequently, the accuracy of environmental analyses depends on both the efficiency and the robustness of the extraction and quantification method. In this work, an off-line solid-phase extraction (SPE) combined with on-line SPE-LC-MS/MS was applied to the simultaneous extraction and quantification of 26 pharmaceutical products, including 18 antibiotics, dissolved in a water phase. Optimal conditions were determined and then applied to assess the contamination level of the targeted drug residues in water collected from four sites in Northern France: a river, the input and output of an aerated lagoon, and a wastewater treatment plant. Drug residues associated with suspended solid matter (SSM) were also quantified in this work using pressurized liquid extraction (PLE) combined with an on-line SPE-LC-MS/MS system in order to complete an assessment of the degree of total background pollution.

A modified cyclen azaxanthone ligand as a new fluorescent probe for Zn2

A new cyclen derivative L, bearing a methyl-chromeno-pyridinylidene hydrazone moiety, was synthesized and studied in MeOH, as potential fluorescent OFF-on-ON sensors for Zn(ii). Photophysical properties of this ligand being PET regulated, L was only weakly emissive in the absence of metal ions (OFF). L fluorescence was increased modestly upon addition of one equivalent of Zn(II), and further increased upon addition of a second equivalent. Therefore, Znu2009:u2009L behaved as a highly sensitive ON sensor for zinc. This efficiency was correlated to Zn(II) coordination via the hydrazone moiety of the fluorophore, producing an efficient CHelation-Enhanced Fluorescence (CHEF) effect. A complementary theoretical study carried out with DFT calculations further elucidated the optical properties.

Synthesis, structural characterization and ionic conductivity of NASICON-type Bax/2Li1-xTi2(PO4)3 (0.4 ≤ x ≤ 1) materials

The NASICON series, with formula Bax/2Li1-xTi2(PO4)3 (0.4xa0≤xa0xxa0≤xa01), has been prepared by solid-state reaction and characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR), Raman, nuclear magnetic resonance (NMR) and impedance spectroscopy (IS). XRD patterns of samples indicated the formation of single phases with rhombohedral structure (space group R-3c). The Rietveld analysis of XRD patterns was performed to deduce location of Li and Ba ions. FTIR, Raman, and NMR techniques showed the only presence of isolated PO4 groups in analyzed phosphates. 31P MAS-NMR spectra were used to investigate Li and Ba distribution and 7Li MAS-NMR spectra to discriminated Li ions with different mobility in conduction paths. A maximum total conductivity of 2.5xa0×xa010−7xa0Sxa0cm−1 and a minimum activation energy of 0.47xa0eV were obtained at room temperature for Ba0.3Li0.4Ti2(PO4)3 (xxa0=xa00.6).