Functionalization of Ti₃C₂ MXene with Diethylenetriamine for a Column-Based Solid-Phase Extraction of Heavy Metals

Transition metal carbides, nitrides, and carbonitrides, known as MXenes, are attracting attention for their potential application in trace detection of heavy metals. This study presents diethylenetriamine-functionalized Ti₃C₂ MXene for trace detection of cadmium and lead ions. Functionalization of Ti₃C₂ significantly improves the adsorption properties of MXenes by replacing native functional groups with silane moieties that contain three amine groups, offering higher affinity for heavy metals. We demonstrate the efficacy of this material as a solid-phase extractor in column-based solid-phase extraction for heavy metal analysis in various food samples. Diethylenetriamine-functionalized Ti₃C₂ coupled with the flame atomic absorption spectrometer exhibits exceptional analytical performance. While maintaining a robust stability for 15 adsorption-desorption cycles, the proposed method shows detection limits of 0.09 ng mL^-1 for cadmium and 1.7 ng mL^-1 for lead, with a linear dynamic range of 0.3-50 ng mL^-1 for cadmium and 5-90 ng mL^-1 for lead, and relative recoveries of 97.50-101.05 and 98.65-100.80% for cadmium and lead ions, respectively. Additionally, relative standard deviations and enrichment factors were calculated as 0.60-4.70% and 42.3 for cadmium ions and 0.65-1.24% and 44.2 for lead ions.