Abstract :

The presented work demonstrates a rapid, selective, ultrasensitive, and low operating cost voltammetric method for the determination of total aluminum at ultra-trace levels. New nanocomposite sensing platforms coated glassy carbon electrodes (GCE) were fabricated and tested for aluminum determination using square wave anodic stripping voltammetry (SWASV). Incorporation of quinalizarin (HAQ) and PtNi nanoparticles (PtNiNPs) into the carbon black ionic liquid paste (Vulcan XC72-IL) modified with Nafion solution was tested. The synthesized PtNiNPs were characterized by TEM, and the shape was octahedra with an average particle size of ca. 9 nm. SEM was used to examine the surface morphologies of the bare and modified electrodes. Vulcan XC72- IL@PtNiNPs@HAQ/GCE showed surprisingly higher activity than Vulcan XC72-IL@PtNiNPs/GCE and Vulcan XC72-IL@HAQ/GCE. The promising results were obtained after optimized the experimental conditions. The calibration curve was linear from 0.05 to 170 μg/L (R2 = 0.989) with a detection limit of 0.21 ng/L and repeatability below 2.1 %. The reproducibility of the sensing platform preparation was equal to 5.3 % (n = 4). Results were verified using recovery (98.6 ± 3.0) and GFAAS. Thus, the proposed sensing platform enhanced the sensitivity due to its large surface area and high electrical conductivity of its components. The study clearly showed that a small change in aluminum content could be followed with satisfactory results employing this approach.