Sensing Cd(II) Using a Disposable Optical Sensor Based on a Schiff Base Immobilisation on a Polymer-Inclusion Membrane. Applications in Water and Art Paint Samples

Abstract

A disposable colour-changeable optical sensor based on an interesting polymer inclusion-membrane (PIM) was designed to determine Cd(II) ions in aqueous medium. The Schiff base 2-acetylpyridine benzoylhydrazone (2-APBH) immobilised on the polymer membrane was used as a sensing molecule. The amounts of the PIM components were optimised by a 32 fractional factorial design with two central points and two blocks. The best optical sensor composition consisted of 2.5 g of poly(vinylchloride) (PVC) as a base polymer, 3 mL of tributyl phosphate (TBP) as a plasticiser, and 0.02 g of 2-APBH as a reagent. The sensor showed a good linear response in the range from 0.02 mg L−1 (limit of detection) to 1 mg L−1 of Cd(II) under the following experimental conditions: pH 9.5 (adjusted using ammonium chloride buffer solution at 0.337 mol L−1), 60 min of exposure time plus 2 min of sonication (pulses at 2 s intervals), and 10 min of short-term stability. The relative standard deviation of the method was determined to be 4.04% for 0.4 mg L−1 of Cd(II). The optical sensor was successfully applied to the determination of Cd(II) in natural-water and art-paint samples.

Some Aromatic Schiff Bases and Their Metal Complexes

“…One of the good precursors for the synthesis of potentially biologically active imine derivatives is 2-acetylpyridine. Besides the potential for medicinal application, Schiff bases of this ketone have a wide range of other uses, such as fluorescent and luminescent probes [34,35], optical sensors for determination of cadmium(II) in natural water and art-paint samples [36], effective catalysts [37], etc. The research has shown that imine derivatives of 2-acetylpyridine and their metal complexes express substantial in vitro activity against various human tumor lines [38,39] and significant cytotoxicity against some solid tumors and leukemia cells [40].…”

Crystallization of Nano-Sized Macromolecules by the Example of Hexakis-[4-{(N-Allylimino)methyl}phenoxy]cyclotriphosphazene

“…Azomethines (Schiff bases) are promising compounds for use in various fields of science and technology: extraction of metals [1,2], analytical chemistry [3], chemosensorics [4], polymer photostabilization [5], etc. Azomethines inhibit steel corrosion in hydrochloric [6] and sulfuric [7] acid solutions since they are easily adsorbed at the metal/solution interface.…”