Cupferron

About: Cupferron is a research topic. Over the lifetime, 367 publications have been published within this topic receiving 4632 citations.

Determination of trace aluminium by adsorptive stripping voltammetry on a preplated bismuth-film electrode in the presence of cupferron.

Abstract: This work reports the use of adsorptive stripping voltammetry (AdSV) for the determination of aluminium on a rotating-disc bismuth-film electrode (BiFE). Al(III) ions in the non-deoxygenated sample were complexed with cupferron and the complex was accumulated by adsorption on the surface of the preplated BiFE. The stripping step was carried out by using a square-wave (SW) potential-time voltammetric excitation signal. The experimental variables as well as potential interferences were investigated and the figures of merit of the method were established. Using the selected conditions, the 3σ limit of detection for aluminium was 0.5 μg l−1 at a preconcentration time of 240 s and the relative standard deviation was 4.2% at the 5 μg 1−1 level for a preconcentration time of 120 s (n = 8). The accuracy of the method was established by analysing water and metallurgical samples.

Adsorptive stripping voltammetric measurements of trace uranium at the bismuth film electrode

Abstract: Bismuth-coated carbon-fiber electrodes have been successfully applied for adsorptive stripping voltammetric measurements of trace uranium in the presence of cupferron. The new protocol is based on the accumulation of the uranium–cupferron complex at a preplated bismuth film electrode held at −0.30 V (versus Ag/AgCl), followed by a negatively-sweeping square-wave voltammetric waveform. Factors influencing the stripping performance, including the film preparation, solution pH, cupferron concentration, adsorption potential and time have been optimized. The resulting performance compares well with that observed for analogous measurements at mercury film electrodes. A detection limit of 0.3 μg/L is obtained in connection to a 10 min adsorption time. The response is linear up to 50 μg/L and the relative standard deviation at 50 μg/L uranium is 3.8% (n = 15; 2 min adsorption). Potential interferences are examined. Applicability to seawater samples is demonstrated. The attractive behavior of the new ‘mercury-free’ uranium sensor holds great promise for on-site environmental and industrial monitoring of uranium.

New solvothermal routes for GaN nanocrystals

Abstract: GaN nanocrystals (see Figure) of hexagonal structure and varying diameters have been prepared by the reaction of hexamethyldisilazane (HMDS) with gallium cupferron or GaCl 3 under solvothermal conditions. The nanocrystals show a size-dependent photoluminescence band in the 260-320 nm region, characteristic of quantum confinement.

A solvothermal route to capped nanoparticles of γ-Fe2O3 and CoFe2O4

Abstract: The decomposition of single or multiple transition metal cupferron complexes in organic solvents under solvothermal conditions and in the presence of long chain amines yields the corresponding oxide nanoparticles. The examples presented here are maghemite γ-Fe2O3 nanoparticles from an FeIII–cupferron complex and spinel CoFe2O4 nanoparticles starting from CoII–cupferron complex and FeIII–cupferron complex taken in suitable proportions. The nanoparticles are capped with n-octylamine or n-dodecylamine. The presence of amine in the reaction is found to be essential for the formation of the product. The magnetic behavior of pressed pellets of these nanoparticles is presented.

Trace Determination of Chromium by Square-Wave Adsorptive Stripping Voltammetry on Bismuth Film Electrodes

Abstract: This works reports the use of adsorptive stripping voltammetry (AdSV) for the trace determination of chromium on a rotating-disk bismuth-film electrode (BFE). During the reductive accumulation step, all the chromium species in the sample were reduced to Cr(III) which was complexed with cupferron and the complex was accumulated by adsorption on the surface of a preplated BFE. The stripping step was carried out by using a square-wave (SW) potential-time voltammetric signal. Electrochemical cleaning of the bismuth film was employed, enabling the same bismuth film to be used for a series of measurements in the presence of dissolved oxygen. The experimental variables as well as potential interferences were investigated and the figures of merit of the method were established. Using the selected conditions, the 3σ limit of detection for chromium was 100 ng L−1 (for 120 s of preconcentration) and the relative standard deviation was 3.6% at the 2 μg L−1 level (n=8). Finally, the method was applied to the determination of chromium in real samples with satisfactory results.