Extraction and determination of trace Pb(II) and Cd(II) from food and water samples using phosphorylated ceramic column

The consumption of water and food contaminated with potentially toxic metals causes serious health issues. It is beneficial to analyze the level of contamination of such water and food resources before supply for household utility. Here, we electrochemically prepared a porous aluminum oxide (AO) disk and studied for the microextraction analysis of Pb(II) and Cd(II) ions in food and water samples. The phosphorylated AO disk was characterized by SEM, EDX and XPS analysis for structural and functional group studies. The phosphorylation significantly increases the chelation of metal ions and enhances the hydrophilicity, leading to significantly shorter analysis time. The prepared material interestingly reduces the spectral interferences by sample cleanup and significantly increases the analyte concentration. Several experimental variables were optimized and the method shows a good detection limit of 0.02 ng mL-1 with RSD 3.52%. The enrichment factor for real samples was found to be 66.6. The presence of co-existing does not much affected and a good tolerance level for other coexisting ions was found for Pb(II) and Cd(II) analyses. The proposed method was validated for its accuracy by standard addition method and by analyzing certified reference materials (NIES 10c and SRM 1572b). The obtained results at 95% confidence level using the Student's t test, are below the critical Student's t value of 4.303, confirming the reliability of procedure. Furthermore, the method shows good precision, with RSD less than 5% for subsequent replicate measurements, reaffirming the consistency and robustness of the method.