Molecularly Imprinted Polyaniline as Solid-Phase Material for the Extraction of UV Filters From Waters

Solid-phase extraction (SPE) using a polyaniline molecularly imprinted polymer (PANI@MIP) is optimized for the extraction of benzophenone-4 (BP4) from aqueous matrices. First, the three main variables influencing the washing step of the SPE method-type, composition, volume, and percolation flow rate of the washing solvent-were investigated. The optimal conditions for the washing step using the new PANI@MIP-SPE for maximum retention of BP4 and elimination of interfering molecules (benzophenone-3 [BP3] and benzophenone [BP]) were determined as follows: 1.25 mL acetonitrile/acetic acid/hexane (45/05/50 v/v/v) as wash solvent at a flow rate of 1 mL min-1. A multiple linear regression model was validated using Student's t-test to identify the most significant variables affecting this step, including the type and volume of each eluent solvent and the volume of the ternary mixture solvents. The reliability of the model was further confirmed by analysis of variance (ANOVA) and Fisher's F-test at alpha = 0.05. The extraction recoveries of the target analyte exceeded 92% over the range of concentrations (from 0.1 to 120 mg L-1), and the maximum retention capacity of PANI@MIP-SPE was 600 mu g g-1, in contrast to 50 mu g g-1 for PANI@NIP-SPE.