Preparation of carboxymethyl-α-cyclodextrin polymer grafted onto nano TiO2 as a novel solid phase extraction sorbent based on a host–guest mechanism

Abstract

Carboxymethyl-α-cyclodextrin polymer grafted onto nano TiO₂ (CM-α-CD PG/nano TiO₂) was fabricated and its feasibility for the determination of levodopa (L-DOPA) was investigated. The synthesized sorbent was characterized by Fourier transform infrared (FT-IR) spectroscopy, Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). The adsorption mechanism is based on the host–guest effect between L-DOPA and CM-α-CD PG grafted on nano TiO₂. The selectivity is due to the size of L-DOPA and also the hydrophobic interaction of CM-α-CD polymer with this compound. The experimental conditions were optimized for the separation/determination of L-DOPA. Under the optimum conditions, the adsorption capacity of CM-α-CD PG/nano TiO₂ for L-DOPA and the preconcentration factor were 63.8 μg g⁻¹ and 20, respectively. The limit of detection (LOD), the relative standard deviation (RSD), and the linear range were 0.016 μg mL⁻¹, 2.3%, and 0.05–1.3 μg mL⁻¹, respectively.