Silica Grafted Imprinted Mesoporous Polymer for the Development of SPE Coupled FAAS Method of Nickel Determination, Removal, and Spent Polymer for Reduction of Permanganate: Multivariate Optimization

Abstract

AbstractA novel silica fabricated allyloxy ethanol based imprinted polymer is synthesised with surface area of 333 m2 g−1 and average pore size of 6.5 nm by an environment friendly one pot surface imprinting process. It was employed for the selective solid‐phase extraction (SPE) of trace Ni(II) in real samples prior to FAAS determination. The factor settings produced via central composite design in response surface methodology (RSM) (pH: 3.6; initial concentration; 800 mg L−1 and time; 15 minute) provide adsorption capacity of 176 mg g−1. Artificial neural network model employed on the RSM data, provided better predictability. Sips isotherm model and BSf kinetic model describes best the sorption phenomena of the homogenous binding terrain. The developed SPE‐coupled FAAS method demonstrate a detection limit of 1.62 μg L−1, quantification limit of 4.17 μg L−1, and Linear dynamic range of 20–8000 μg L−1. It was successfully applied to determine nickel in food (Spinach, Radish, Green tea infusion, Black tea infusion, Coffee, Soya milk, Chocolate Soya milk, Tobacco) and wastewater samples (>99 % removal). For five replicate determinations, the method‘s relative standard deviation was 2.3 %. The method was validated by analysing two certified reference materials, and the outcomes were well‐congruent with standard values. For the synthesised polymer Ni(II) exhibits higher distribution ratio than other competing ions (Cu(II), Pb(II), Cd(II), and Zn(II)) with the imprinting factor; β values of 5.73, 4.98, 6.80, and 5.04 respectively. The reusability experiments revealed that APS@Ni‐IIP retains a strong adsorption efficacy even after 15 cycles and after its exhaustion it was employed as catalyst for reducing permanganate ions, further reducing pollution. The rigid structure of mesoporous silica contributes to its acid resilience and reusability, which can lead to a relative increase in polymer performance in absorption rate and selectivity. Apart from the novelty in the synthesis, thorough examination of the method and material selectivity (in binary, ternary and multielement system), multi fold applications of determination, removal of Ni(II) and reduction of permanganate ions, makes APS@Ni‐IIP a promising candidate for environmental remediation.