Development of a novel polymer inclusion membrane sensor for sensitive and selective determination of aluminum in diverse real samples

Abstract

A new, sensitive and selective bulk sensor membrane has been designed for the quantification of trace amounts of aluminum [Al3+] employing a polymer inclusion membrane (PIM). This innovative membrane has been used analytical performance, including a low reported detection limit, a relatively broad calibration range, membrane regeneration, and application to several real samples. The PIM contains 35% di(2-ethylhexyl)phosphoric acid (D2EHPA) as the carrier, 50% poly(vinyl chloride) (PVC) as the base polymer, 12.5% dioctyl sebacate (DOS) as the plasticizer, and 2.5% of the colorimetric reagent for Al3+, 4-(2-amino-3-hydroxy-pyridine-4-ylazo)1,5-dimethyl-2-phenyl-1,2-dihydropyra-zol-3-one (AHDDO). In this research, Al3+ ions are absorbed into the PIM forming an Al3+-D2EHPA complex, which then interacts with AHDDO, resulting in a pink Al3+-AHDDO complex (λmax = 589 nm). A central composite design was utilized to optimize various parameters such as the quantity of additives and AHDDO, pH levels, and response time, all of which significantly influence the sensor’s performance. Under the ideal circumstances, the sensor membrane achieves a lower limit of quantification (LOQ) of 5.00 ng mL−1 and a limit of detection (LOD) of 1.50 ng mL−1 compared to other sensor reported early. The sensor membrane exhibits excellent stability and reproducibility with a relatively long lifetime, indicating its capability for accurate and reliable monitoring of Al3+ ion concentrations. The sensor was successfully regenerated by 0.10 M EDTA and 0.10 M NaF solution. The response was reproducible and reversible, with an RSD of 1.45% or more. The PIM- AHDDO sensor was successfully applied to determine Al3+ ions in real samples from pharmaceutical, biological, and environmental sources.