MIL-101(Fe)@TiO2 nanotube composite material is used for the solid phase extraction of non-steroidal anti-inflammatory drugs under the synergy of multiple interactions

Abstract

Increasing the adsorption sites and effective interactions between sorbents and the targets can improve the solid-phase extraction (SPE) efficiency. Herein, based on the advantages of MOFs and TiO₂ nanotubes (TiO₂ NTs), an MIL-101(Fe)@TiO₂ NT composite was prepared and applied to extract non-steroidal anti-inflammatory drugs (NSAIDs) from water samples coupled with high performance liquid chromatography (HPLC). Through characterization, it was established that MIL-101(Fe) was effectively composited on the surface and inside the TiO₂ nanotubes, increasing effective adsorption sites. The obtained composite material well retains the structure and functional groups of the two original materials, and while retaining the original force with the target, it achieves a synergistic effect and produces more interactions with the target. Therefore, the extraction efficiency was greatly improved. The recovery efficiency reached 97.7–105.1% with an RSD of less than 6.71%, the detection limit was 0.1–0.2 μg L⁻¹, and the linear range was 1–200 μg L⁻¹ with a determination coefficient of 0.9972–0.9994. Owing to the stability of the two original materials, the composite material could be recycled and reused to extract NSAIDs up to 15 times without a loss of the recovery rate. Satisfactory results were obtained when it was used to extract NSAIDs from the Yellow River. These results indicate that the synthesized MIL-101(Fe)@TiO₂ NT material is a promising sorbent to extract NSAIDs at trace concentrations with high efficiency and long lifetimes.