Linear scan voltammetric indirect determination of AlIII by the catalytic cathodic response of norepinephrine at the hanging mercury drop electrode

Application of adsorptive stripping voltammetry based on PbFE for the determination of trace aluminum released into the environment during the corrosion process

This work presents a new fast and sensitive method for voltammetric determination of Al(III) as Al(III)-cupferron complexes, which was used for the analysis of solution after exposure of aluminum alloy AA2024. Experimental conditions of voltammetric measurement such as preconcentration time, potential, and operating parameters were optimized. The formed Al(III)-cupferron complexes were adsorbed on an in situ plated lead film electrode (PbFE) using the potentials of -1.2 V (15 s) and -0.7 V (60 s) versus Ag/AgCl electrode. The promising results were obtained in 0.1 mol L^-1 ammonia buffer at pH = 8.15 and 6 ∙ 10^-5 mol L^-1 Pb(II), 3 ∙ 10^-4 mol L^-1cupferron. The calibration graph was linear from 1 ∙ 10^-10 to 2 ∙ 10^-7 mol L^-1 with the calculated detection limit of 3.3 ∙ 10^-11 mol L^-1, repeatability with RSD of 4.9% (n = 5). The accuracy was established by analysis of the synthetic sample.

NiFe2O4 nanospheres functionalized with 2-(2, 4-Dihydroxyphenyl)-3, 5, 7-trihydroxychromen-4-one for selective solid-phase microextraction of aluminium

Herein, a rational combination of dispersive solid-phase sorbent and 2-(2, 4-Dihydroxyphenyl)-3, 5, 7-trihydroxychromen-4-one (morin) was proposed for sensitive and selective determination of Al³⁺ ion. Nickel ferrite nanospheres (NiFe₂O₄ NS) functionalized with morin was used to preconcentrate and estimate Al³⁺ via the formation of fluorescent complex at pH 7.0. The functionalization was assisted by anionic surfactant sodium dodecyl sulphate (SDS) and ultrasonication. The results revealed that the fluorescence intensity of Al-morin/SDS@ NiFe₂O₄ NS is higher than Al-morin. Functionalization of NiFe₂O₄ NS with morin was confirmed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR), powder X-ray diffractometer (PXRD), and fluorescence spectroscopy. Under the optimum conditions, the fluorescence intensity increased with increasing of Al³⁺ concentrations in the range of 0.28-500.0 ng mL^-1 with LOD (S/N = 3) of 0.09 ng mL^-1. The method was applied for the determination of Al³⁺ in natural waters and human serum samples with recoveries % of 97-104% and RSDs % of 2-4%.

The first report of X-ray characterized organosilatrane-based receptors for the electrochemical analysis of Al3+ ions

The electrochemical behaviour of aryl–alkyl ether functionalized organosilatranes has been studied by square wave voltammetry (SWV) using a gold electrode.

Quantitative Determining of Ultra-Trace Aluminum Ion in Environmental Samples by Liquid Phase Microextraction Assisted Anodic Stripping Voltammetry

Direct detecting of trace amount Al(III) in aqueous solution by stripping voltammetry is often frustrated by its irreversible reduction, resided at −1.75 V (vs. Ag/AgCl reference), which is in a proximal potential of proton reduction. Here, we described an electroanalytical approach, combined with liquid phase microextraction (LPME) using ionic liquid (IL), to quantitatively assess trace amount aluminum in environmental samples. The Al(III) was caged by 8-hydroxyquinoline, forming a superb hydrophobic metal⁻chelate, which sequentially transfers and concentrates in the bottom layer of IL-phase during LPME. The preconcentrated Al(III) was further analyzed by a square-wave anodic stripping voltammetry (SW-ASV). The resulting Al-deposited electrodes were characterized by scanning electron microscopy and powder X-ray diffraction, showing the intriguing amorphous nanostructures. The method developed provides a linear calibration ranging from 0.1 to 1.2 ng L^−1 with a correlation coefficient of 0.9978. The LOD attains as low as 1 pmol L^−1, which reaches the lowest report for Al(III) detection using electroanalytical techniques. The applicable methodology was implemented for monitoring Al(III) in commercial distilled water.

Acetylcholinesterase inhibition-based biosensor for aluminum(III) chronoamperometric determination in aqueous media

A novel amperometric biosensor for the determination of Al(III) based on the inhibition of the enzyme acetylcholinesterase has been developed. The immobilization of the enzyme was performed on screen-printed carbon electrodes modified with gold nanoparticles. The oxidation signal of acetylthiocholine iodide enzyme substrate was affected by the presence of Al(III) ions leading to a decrease in the amperometric current. The developed system has a detection limit of 2.1 ± 0.1 μM for Al(III). The reproducibility of the method is 8.1% (n = 4). Main interferences include Mo(VI), W(VI) and Hg(II) ions. The developed method was successfully applied to the determination of Al(III) in spiked tap water. The analysis of a certified standard reference material was also carried out. Both results agree with the certified values considering the respective associated uncertainties.