MIL-100(Fe)@PES composite polymer beads for adsorption and preconcentration of pharmaceuticals in water samples

• Novel MIL-100(Fe)@PES beads exhibit 109 mg/g capacity for diclofenac adsorption. • MIL-100(Fe)@PES beads show fast adsorption kinetics for diclofenac. • Excellent performance for low-level pollutant enrichment under flow conditions. In this study, we developed MOF@polymer composite beads by incorporating MIL-100(Fe) into polyethersulfone (PES) for the adsorption and preconcentration of pharmaceuticals from water. By varying the MOF/polymer ratio, composites with high porosity and surface areas up to 716 m 2 g −1 were obtained, whose adsorption performance improved with increasing MOF content. The optimized MIL-100(Fe)@PES composite exhibited a maximum adsorption capacity of 109 mg g −1 for diclofenac (DCF), with equilibrium reached in 6 h. Adsorption followed a Langmuir model, suggesting monolayer coverage, and was driven by hydrogen bonding between DCF and MIL-100(Fe). The composite demonstrated excellent reusability, maintaining adsorption efficiency over three consecutive cycles with a relative standard deviation of 0.5 %. By packing the compound on a flow-through solid phase extraction (SPE) HPLC column, limits of detection and quantification of 1.2 and 4.0 µg L- 1 were achieved for DCF, with intra- and inter-day precision below 6.7 %. The extraction efficiency increased with composite mass up to 1.0 g and was optimized at a flow rate of 1.0 mL min −1 . Finally, the MIL-100(Fe)@PES beads were tested for the extraction and preconcentration of diclofenac and ibuprofen from groundwater, achieving enrichment factors of 6 and 4, respectively, with no significant matrix effects.