A New and All-Solid-State Potentiometric Aluminium Ion Sensor for Water Analysis

Abstract

An all-solid-state potentiometric electrode system for aluminium ion determination was developed with a new aluminium ion sensor as the working electrode based on a new ionophore for aluminium ion, 1,1′-[(methylazanediyl)bis(ethane-2,1-diyl)]bis[3-(naphthalen-1-yl)thiourea] (ACH). The reference electrode was a potassium ion sensor, which acts as a pseudo-reference. Both electrodes were made from Ag/AgCl screen-print electrodes fabricated from a non-plasticized and photocurable poly(n-butyl acrylate) membrane that contained various other membrane components. The pseudo-reference potential based on the potassium ion sensor was fixed in 0.050 M KNO3, and such concentration of K+ ion did not interfere with the measurement of the Al3+ ion using the aluminium sensor. With such a pseudo-reference and in the presence of 0.050 M KNO3 as a background medium, the aluminium sensor measured changes of aluminium ion concentrations linearly from 10−6 to 10−2 M Al3+ ion with a Nernstian response of 17.70 ± 0.13 mV/decade. A low detection limit of 2.45 × 10−7 M was achieved with this all-solid-state potentiometric system. The aluminium sensor was insensitive to pH effects from 2.0 to 8.0 with a response time of less than 50 s. Under optimum conditions, a lifetime of 49 days was achieved with good sensor selectivity, reversibility, repeatability, and reproducibility. The all-solid-state electrode system was applied to analyze the Al3+ ion content of water samples from a water treatment plant. Compared with the conventional potentiometric detection system for aluminium ions, the new all-solid-state aluminium ion sensor incorporating a pseudo-reference from the potassium sensor demonstrated similar analytical performance. It thus provided a convenient means of aluminium content analysis in water treatment plants.

Exploitation of bis(tert‐butylaminomethyl)pyridine as a chemical modifier in a carbon paste electrode for sensitive and selective potentiometric determination of Al3+ ion in pharmaceutical and water samples

“…Figure 3 depicts the actual potential against time for a bis(tert‐butylaminomethyl)pyridine‐based electrode. In the entire concentration range, the electrode‘s potential equilibrium was reached very quickly, in less than 5 s which can be considered as a good improvement from the previously published sensors [2, 26–30, 34, 35]. The complexation of fast‐moving Al 3+ ions with the ligand bis(tert‐butylaminomethyl)pyridine on the surface of the upper paste layer and Al 3+ solution is the cause of this.…”

“…Moreover, after this time, detection limit was increased from 1.0±(0.20)×10 −7 mol L −1 to 6.23±(0.75)×10 −7 mol L −1 . So, the proposed electrode can be utilised for more than 4 months without significantly changing its response criterion to Al 3+ and this was much longer than other reported Al 3+ sensors [2, 25, 26, 28, 30, 32]. Decreasing response after this time can be attributed to decay of the applied ionophore after a long period at ambient temperature.…”

“…The effectiveness of this MCPE for Al 3+ ion detection was compared with the Al 3+ ion sensors previously reported in PVC [28–30, 32, 34, 35], screen printed [2], and carbon paste [1, 25–27] matrices with various ionophores. Tables 6 reveal that the new method‘s pH range and was nearly comparable.…”

“…The naturally occurring form of aluminium is unreactive and stable towards biological structures. However, living things like plant life, algae, and fish can soak up its soluble formula when it is discharged into the acidic environment by soil and rocks [2,3]. Chronic kidney failure and other conditions including Alzheimer's, Parkinson's, and autism problems are all brought on by high amounts of aluminium [4,5].…”

Chamotte Clay: A Natural Adsorbent for Separation and Preconcentration of Aluminium

“…Aluminium mainly enters the human body through the consumption of food and water [5] whereas WHO set the tolerable value of aluminium in drinking water to 0.2 mg L -1 [6]. Studies over the last decade reveal that aluminium accumulates in internal organs and excessive levels can cause harmful effects to lungs and kidneys [7,8]. Parkinson's and Alzheimer's diseases are also linked to overdose of aluminium in the human body [9][10][11].…”