Etude spectroscopique de purines et pyrimidines : fluorescence, phosphorescence et spectrometrie d'absorption derivee : applications analytiques

SIGLECNRS T Bordereau / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

A spectrofluorimetric method for the determination of pindolol in natural waters using various organic and cyclodextrin media

International audienc

Photodegradation study of insecticide fenvalerate by NMR and GC-MS and the structural elucidation of its metabolites

International audienc

A NEW DIRECT LASER PHOTO-INDUCED FLUORESCENCE METHOD COUPLED ON-LINE WITH LIQUID CHROMATOGRAPHIC SEPARATION FOR THE SIMULTANEOUS DETERMINATION OF ANILIDES PESTICIDES

International audienc

Solvolysis kinetic study and direct spectrofluorimetric analysis of the fungicide benomyl in natural waters

International audienceA direct spectrofluorimetric method for the quantitative analysis of benomyl in natural waters is described. Benomyl is an instable, fluorescent fungicide that mainly decomposes into carbendazim and n-butyl-isocyanate in organic and aqueous solutions. The kinetics of benomyl solvolysis reactions were investigated in organic solvents (methanol and acetonitrile) and in aqueous solvent systems, including β–cyclodextrin (β-CD), sodium dodecyl sulfate (SDS), dodecyltrimethylammonium chloride (DTAC), cetyltrimethylammonium chloride (CTAC), cetyltrimethylammonium hydroxide (CTAOH), Brij-700, Triton X-100 and water, at different pH and/or NaOH concentrations. The benomyl fluorescence signal was found to be quasi-completely stable in 10-2 M NaOH aqueous solution, various alkaline (10-2 M NaOH) organized media, β-CD neutral solution and Triton X-100 aqueous solutions of different pH. Based on these results, a direct spectrofluorimetric analytical method was developed for the determination of benomyl in 10-2 M NaOH aqueous solution and Triton X-100 solutions (pH7 and 10-2 M NaOH), with wide linear dynamic range (LDR) values of two to three orders of magnitude, very low limit of detection (LOD) and limit of quantification (LOQ) values of, respectively, 0.002-0.5 ng/mL and 0.007-2.0 ng/mL, and small relative standard deviation (RSD) values of 0.2-1.7 %, according to the medium. This direct spectrofluorimetric method was applied to the evaluation of benomyl residues in natural waters, with satisfactory recovery values (87-94%).</p

Determination of Agmatine Rate by Spectrofluorimetric Method in Alkaline Medium: Optimization and Application on Shrimp.

International audienc

Development of online automatic detector of hydrocarbons and suspended organic matter by simultaneously acquisition of fluorescence and scattering

International audienc

Light effects on Carbofuran and Fluometuron: Impact on natural waters. Spectrophotometric study

International audienc

Rapid removal of fungicide thiram in aqueous medium by electro-Fenton process with Pt and BDD anodes

International audienceThe electro-Fenton (EF) process was used to assess the electrochemical degradation of the fungicide thiram and its complete removal from water using an undivided electrolytic cell equipped with Pt or BDD anode and carbon felt cathode. Hydroxyl radicals, produced homogeneously in bulk solution from electrochemically generated Fenton's reagent (• OH) and heterogeneously on the anode surface (M(• OH)) from oxidation of water, reacted with thiram leading to its fast oxidation. Oxidative degradation and mineralization kinetics were monitored by chromatographic analysis (HPLC) and total organic carbon (TOC) measurements. The electrochemical degradation of thiram by hydroxyl radicals followed a pseudo-first-order reaction kinetics with an absolute rate constant kabs(Thir) of 5.54 (± 0.03) × 10 9 M-1 s-1 , determined by competition kinetics method. The TOC removal rate values were found significantly higher with BDD anode than Pt anode. Thus, almost complete mineralization (92%) of thiram solution was obtained when using BDD anode. 2 These results highlight the major role of heterogeneous BDD(• OH) formed in the mineralization of thiram. The contribution of homogeneous • OH in mineralization of thiram was found relatively low due to its specific aliphatic structure. The efficiency of the EF process was evaluated by determining mineralization current efficiency and energy consumption per gram of TOC removed. Degradation by-products and inorganic ions, such as nitrate (NO3 −), nitrite (NO2 −), ammonium (NH4 +) and sulfate (SO4 2−) formed during mineralization process, were identified by GC-MS and ionic chromatography analyses and a plausible mineralization pathway was proposed

Environmental Aspects of the Photodegradation of Maneb and Propanil in Various Media

International audienceManeb and propanil are two commonly used pesticides that pose many environmental problems. Their rates of photodegradation have been studied by means of spectrophotometric methods using UV-Visible spectrophotometry. The photodegradation kinetics showed that these pesticides were sensitive to light. Second order kinetics was observed in water and therefore pesticides might be very persistent in water. In addition, spectrofluorometry was used to measure their infiltration rates through soil. This was used to assess the level of risks posed by the exposure of pesticides to the environment showing that, Maneb and propanil with respectively infiltration rates of 1.29 cm/h and 26.7 cm/h are potential sources of high risk of contamination for surface and ground waters