MCM-41 based dispersive micro-solid phase extraction of selected cephalosporin antibiotic residues from water samples prior to liquid chromatographic quantification

• A D-µ-SPE–UHPLC-DAD method was developled for cephalosporins analysis in water. • Mesoporous silica (MCM-41) nanostructured material w as an sorbent in D-µ-SPE. • Factors that influence the extraction process oprmised using design of experiments. • The MCM-41 adsorbent showed high extraction efficiencies the target analytes. • Preconcentration and quantification of cephalosporins in real water was achieved. The occurrence of antibiotics in water bodies is of concern owing to the serious risk they pose to the environment, water security, aquatic organisms, and human health. In this study, mesoporous silica (MCM-41) nanostructured material was synthesised and characterized by various analytical techniques to determine its morphology and dimension, functional groups, surface charge, and textural properties. The nanostructured MCM-41 was used as an adsorbent in ultrasound-assisted dispersive micro solid-phase extraction (UA-D-µ-SPE) of cefadroxil (CFDX) and cephalexin (CPLX) in water samples. The concentration of the analytes in aqueous solution and real water samples was determined using high-performance liquid chromatography coupled with diode array detection (HPLC-DAD). The developed method for CFDX and CPLX in various water samples exhibited relative linear ranges of 0.1–600 µg/L and 0.1–550 µg/L, respectively, and correlation coefficients ranging from 0.9923–0.9993. Under optimum condition, the UA-D-µ-SPE/HPLC-DAD method displayed low limits of detection (LOD) and quantification (LOQ), with values ranging from 0.02–0.16 µg/L and 0.067–0.53 µg/L, respectively. The investigated intraday and interday accuracy in spiked water samples showed acceptable extraction efficiencies with a range of 73.5–98.1% and a relative standard deviation less than 6.0%. Moreover, the performance of MCM-41 was also assessed for the removal of cephalosporin antibiotics aqueous solutions. The kinetic and isotherm studies revealed that the adsorption process followed pseudo-second order and the Langmuir model, respectively. Furthermore, the maximum adsorption capacities for CFDX and CPLX were 43.2 and 47.8 mg/g. Lastly, the UA-D-µ-SPE/HPLC-DAD method was successfully applied in extracting, preconcentrating, separating and determining CFDX and CPLX in wastewater and surface water samples. These results demonstrated that MCM-41 can be applied in the removal of cephalosporin antibiotics from aquatic environments.