Zinc detection in oil-polluted marine environment by stripping voltammetry with mercury-free nanoporous gold electrode

International audienceAbstract Detection of Zn(II) in oil-polluted seawater via square-wave anodic stripping voltammetry (SW-ASV) utilizing thin gold electrodes sputtered onto nanoporous poly(acrylic acid)-grafted-poly(vinylidene difluoride) (PAA-g-PVDF) membrane is herein reported. Prior to SW-ASV, PAA grafted nanopores demonstrated to efficiently trap Zn(II) ions at open circuit. This passive adsorption followed a Langmuir law. An affinity constant of 1.41 L \upmu μ mol $$^{-1}$$ - 1 and a maximum Zn(II) adsorbed mass q $$_{max}$$ max of 1.21 \upmu μ mol g $$^{-1}$$ - 1 were found. Applied SW-ASV protocol implied an accumulation step (− 1.2 V for 120 s) followed by a stripping step (− 1.2 to 1 V; 25 Hz; step: 4 mV; amplitude: 25 mV; acetate buffer (pH 5.5)). It revealed a Zn redox potential at − 0.8 V (Ag/AgCl pseudo-reference). Multiple measurements in synthetic waters close to the composition of production waters exhibited a decreasing precision with the number of readings R (1.65 $$\%$$ % (R = 2) and 6.56 $$\%$$ % (R = 3)). These membrane-electrodes should be used as disposable. The intra-batch mean precision was 14 $$\%$$ % (n = 3) while inter-batches precision was 20 $$\%$$ % (n = 15). Linear and linear-log calibrations allow exploitation of Zn(II) concentrations ranging from 10 to 500 \upmu μ g L $$^{-1}$$ - 1 and 100 to 1000 \upmu μ g L $$^{-1}$$ - 1 respectively. The LOD was 4.2 \upmu μ g L $$^{-1}$$ - 1 (3S/N). Thanks to obtained calibration, a detected Zn(II) content of 1 ppm in a raw production water from North Sea oil platform was determined

Characterization of crude oil interfacial material isolated by the wet silica method

COMInternational audienc

TIMPZ: an exquisite building block for metal/hydrogen coordination polymers

The novel polynitrogenated ligand tetra-[4(5)-imidazoyl]pyrazine (TIMPZ, 1) and its pincer complex of Fe-II are described. This ligand has an outstanding ability to aggregate in 1D-superstructures by means of hydrogen bonding or metal chelation. TIMPZ shows an unprecedented conformational control over the supramolecular assembly. Metal or hydrogen coordination switches the conformation of peripheral rings driving the assembly preferences. For [Fe-n(TIMPZ)(n+1)](2n+) complexes, UV/Vis spectroscopy shows a bathochromic shift of the main visible absorption band with higher n values. TIMPZ also has hydrogen-bond triggered excited-state intramolecular proton transfer (ESIPT) fluorescence, which is completely inhibited by chelation with transition metals20191722912294FAPESP – Fundação de Amparo à Pesquisa Do Estado De São Paulo14/25770‐