Micro solid phase extraction of Pb (II) and Cu (II) from water and food samples with MWCNTs@Nb₂O₅@ NiMn2O4 nanocomposite

Exposure to heavy metals through activity and food consumption is a common cause of concern, and metals such as Pb (II) and Cu (II) have been shown to exhibit toxic effects even at low concentrations. In order to enhance the sensitivity and selectivity of heavy metal analyses, a novel MWCNTs@Nb 2 O 5 @NiMn 2 O 4 nanocomposites was synthesized and utilised in micro solid-phase extraction (µ-SPE) technique. The robust, morphological, crystalline and surface properties of the synthesized adsorbent were obtained by a range of analytical techniques, including FT-IR (Fourier Transform Infrared Spectroscopy), FE-SEM (Field Emission Scanning Electron Microscopy), XRD (X-ray Diffraction), and BET (Brunauer-Emmett-Teller) analyses. Optimization of analytical conditions was conducted at a pH of 8.0, and the proposed method was successfully applied for a various samples including, coffee, tobacco, corn kernels, wheat chickpeas, semolina, roasted chickpeas, and tap water and river water. The determination of metal ions was performed by flame atomic absorption spectroscopy (FAAS); the enrichment factor was set at 20. A preconcentration factor of 20 was achieved under the optimized experimental conditions. The LOQ values for Pb (II) and Cu (II) were determined to be 18.5 µg/kg and 17.4 µg/kg, respectively. The suggested method’s intra-day and inter-day precision, measured as RSD%, were 3.1% and 4.2%, respectively, indicating acceptable repeatability and intermediate accuracy. In the process of modifying the method, the incorporation of 8433 Corn Bran and TMDA 64.3 sections as reference materials was undertaken. The resulting alternatives demonstrate that the proposed µ-SPE method offers a sensitive, selective, and applicable analytical solution for the determination of Pb (II) and Cu (II) in food and water matrices.