Functionalization\nof Ti<sub>3</sub>C<sub>2</sub> MXene\nwith Diethylenetriamine for a Column-Based Solid-Phase Extraction\nof Heavy Metals

Transition metal carbides, nitrides, and carbonitrides,\nknown as\nMXenes, are attracting attention for their potential application in\ntrace detection of heavy metals. This study presents diethylenetriamine-functionalized\nTi<sub>3</sub>C<sub>2</sub> MXene for trace detection of cadmium and\nlead ions. Functionalization of Ti<sub>3</sub>C<sub>2</sub> significantly\nimproves the adsorption properties of MXenes by replacing native functional\ngroups with silane moieties that contain three amine groups, offering\nhigher affinity for heavy metals. We demonstrate the efficacy of this\nmaterial as a solid-phase extractor in column-based solid-phase extraction\nfor heavy metal analysis in various food samples. Diethylenetriamine-functionalized\nTi<sub>3</sub>C<sub>2</sub> coupled with the flame atomic absorption\nspectrometer exhibits exceptional analytical performance. While maintaining\na robust stability for 15 adsorption–desorption cycles, the\nproposed method shows detection limits of 0.09 ng mL<sup>–1</sup> for cadmium and 1.7 ng mL<sup>–1</sup> for lead, with a linear\ndynamic range of 0.3–50 ng mL<sup>–1</sup> for cadmium\nand 5–90 ng mL<sup>–1</sup> for lead, and relative recoveries\nof 97.50–101.05 and 98.65–100.80% for cadmium and lead\nions, respectively. Additionally, relative standard deviations and\nenrichment factors were calculated as 0.60–4.70% and 42.3 for\ncadmium ions and 0.65–1.24% and 44.2 for lead ions.