Micro solid phase extraction of lead and cadmium using functionalized nanodiamonds@CuAl2O4@HKUST-1 nanocomposite for FAAS analysis in food and water samples

Abstract

This study focuses on the development and application of a novel nanocomposite (functionalized nanodiamonds@CuAl2O4@HKUST-1)-based µ-SPE method for the sensitive and selective extraction of Pb and Cd from food and water samples. The technique offers high sensitivity and selectivity, allowing accurate measurement of these metals at trace levels. The detection limit is 0.031 µg kg−1 for Cd and 0.052 µg kg−1 for Pb, with a relative standard deviation of 1.7 % for Cd and 4.8 % for Pb. The method was successfully applied to real samples and efficiently quantified Pb and Cd in food and natural water samples. The highest concentrations were found in red lentils (0.274 µg kg−1 Pb) and fresh mint (0.197 µg kg−1Cd), but still below recommended limits set by FAO/WHO (300 µg kg−1 for Pb and 200 µg kg−1 for Cd). It promises to ensure food safety, monitor environmental contamination, and informs regulatory decisions to protect public health.