PVC-DOS membrane immobilized with 2-amino-4-(3-chloro-phenylazo) pyridine-3-ol for environmentally friendly detection of Cd(II) ions

Abstract

The present study demonstrates the green selective microdetermination of Cd²⁺employing a newly established polymer inclusion membrane (PIM) in an environmental process. The PIM is made up of 40 % di(2-ethylhexyl) phosphoric acid (D2EHPA), 9 % dioctyl sebacate (DOS), and 50 % polyvinyl chloride (PVC). 2-Amino-4-(3-chlorophenylazo) pyridine-3-ol (ACPAP) is the colorimetric reagent utilized to determine Cd²⁺ concentration. Cd²⁺ is elicited into the PIM in this system as the cadmium-D2EHPA complex, which then reacts with ACPAP. ACPAP yields a violet Cd²⁺−ACPAP complex. The λ_max for the PIM based optode was 657 nm. The variables pH, quantity of reagent, quantity of additive, and duration of response, which substantially influence the response of the proposed optode, were optimized using design of experiment (DOE) statistical method. At ideal conditions, the optode membrane's reproducibility, high stability, and relatively extended lifetime indicate its potential for accurate and precise monitoring of Cd²⁺ ion concentration. Under ideal conditions, the optode has a detection limit of 1.60 ng mL⁻¹ and a measurement (quantification) limit of 5.0 ng mL⁻¹. The PIM-ACPAP system was utilized effectively to detect Cd²⁺ ions in environmental real samples.